diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 73c35760107e6b5e2e827d6514a9641bd9aa6b89..f7bfbec0aa051d5fe34b9bac771cc3de7f645013 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,5 +1,41 @@
-- repo: https://github.com/ambv/black
-  rev: 20.8b1
-  hooks:
-  - id: black
-    language_version: python3.6
+repos:
+-   repo: https://github.com/psf/black
+    rev: 21.5b0
+    hooks:
+    - id: black
+-   repo: https://github.com/PyCQA/isort
+    rev: 5.8.0
+    hooks:
+    - id: isort
+      args: ["--profile", "black"]
+-   repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v0.910
+    hooks:
+    - id: mypy
+      args:
+        - "--ignore-missing-imports"
+        - "--install-types"
+        - "--non-interactive"
+-   repo: local
+    hooks:
+    - id: pylint
+      name: pylint
+      entry: ./bin/pylint.sh
+      language: python
+      types: [python]
+-   repo: https://github.com/Lucas-C/pre-commit-hooks
+    rev: v1.1.10
+    hooks:
+    - id: insert-license
+      exclude: __init__\.py
+      files: \.py$
+      args:
+        - --license-filepath
+        - license_header.txt
+-   repo: https://gitlab.com/devopshq/gitlab-ci-linter
+    rev: v1.0.3
+    hooks:
+    - id: gitlab-ci-linter
+      args:
+        - "--server"
+        - "https://git.duniter.org"
diff --git a/.pylintrc b/.pylintrc
index 71a3c091e98cebc67ab84d84ee4b036550446af4..e9ba7a690aa7fcb71db55a815549ec0d60384e36 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -60,12 +60,36 @@ confidence=
 # --enable=similarities". If you want to run only the classes checker, but have
 # no Warning level messages displayed, use "--disable=all --enable=classes
 # --disable=W".
-disable=blacklisted-name,
+disable=missing-module-docstring,
+        missing-class-docstring,
+        line-too-long,
+        too-many-lines,
+        duplicate-code,
+        no-absolute-import,
+        fixme,
+        too-many-ancestors,
+        too-many-locals,
+        too-many-instance-attributes,
+        too-few-public-methods,
+        too-many-public-methods,
+        too-many-branches,
+        too-many-arguments,
+        too-many-statements,
         invalid-name,
+        broad-except,
+        locally-disabled,
+        suppressed-message,
+        no-self-use,
+        dict-keys-not-iterating,
+        ungrouped-imports
+
+# Enable the message, report, category or checker with the given id(s). You can
+# either give multiple identifier separated by comma (,) or put this option
+# multiple time (only on the command line, not in the configuration file where
+# it should appear only once). See also the "--disable" option for examples.
+enable=blacklisted-name,
         empty-docstring,
         unneeded-not,
-        missing-module-docstring,
-        missing-class-docstring,
         missing-function-docstring,
         misplaced-comparison-constant,
         unidiomatic-typecheck,
@@ -75,8 +99,6 @@ disable=blacklisted-name,
         bad-mcs-method-argument,
         bad-mcs-classmethod-argument,
         single-string-used-for-slots,
-        line-too-long,
-        too-many-lines,
         trailing-whitespace,
         missing-final-newline,
         trailing-newlines,
@@ -88,7 +110,6 @@ disable=blacklisted-name,
         invalid-characters-in-docstring,
         multiple-imports,
         wrong-import-order,
-        ungrouped-imports,
         wrong-import-position,
         useless-import-alias,
         import-outside-toplevel,
@@ -107,20 +128,10 @@ disable=blacklisted-name,
         non-ascii-bytes-literal,
         raw-checker-failed,
         bad-inline-option,
-        locally-disabled,
         file-ignored,
-        suppressed-message,
         useless-suppression,
         deprecated-pragma,
         use-symbolic-message-instead,
-        too-many-ancestors,
-        too-many-instance-attributes,
-        too-few-public-methods,
-        too-many-public-methods,
-        too-many-branches,
-        too-many-arguments,
-        too-many-locals,
-        too-many-statements,
         unused-argument,
         apply-builtin,
         basestring-builtin,
@@ -139,7 +150,6 @@ disable=blacklisted-name,
         delslice-method,
         getslice-method,
         setslice-method,
-        no-absolute-import,
         old-division,
         dict-iter-method,
         dict-view-method,
@@ -182,17 +192,11 @@ disable=blacklisted-name,
         xreadlines-attribute,
         deprecated-sys-function,
         exception-escape,
-        comprehension-escape
-
-# Enable the message, report, category or checker with the given id(s). You can
-# either give multiple identifier separated by comma (,) or put this option
-# multiple time (only on the command line, not in the configuration file where
-# it should appear only once). See also the "--disable" option for examples.
-enable=singleton-comparison,
-       bad-classmethod-argument,
-       multiple-statements,
-       c-extension-no-member
-
+        comprehension-escape,
+        singleton-comparison,
+        bad-classmethod-argument,
+        multiple-statements,
+        c-extension-no-member
 
 [REPORTS]
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000000000000000000000000000000000000..c10af392392e2d44214e7a72d4830a4d1d9685cf
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,75 @@
+# Contribute guide
+
+## Pre-commit
+We are using [`pre-commit`](https://pre-commit.com/) tool to perform checks on staged changes before committing.
+We are using it for `black` formatting, `isort` imports sorting, `pylint` code linting, `mypy` typing, licence headers and `gitlab-ci` linting.
+
+Install `pre-commit` from your distribution or install it from `pip`:
+```bash
+sudo apt install pre-commit
+```
+or
+```bash
+pip install --user pre-commit
+```
+
+To install the `git-hooks`, in the project folder, run:
+```bash
+pre-commit install
+```
+Then each time you commit changes, the hooks will perform checks.
+
+To manually run one of the tool above, run (eg for `isort`):
+```bash
+pre-commit run --all-files isort
+```
+To run all checks on all files:
+```bash
+pre-commit run -a
+```
+
+### Authorization for GitLab CI linter hook
+`pre-commit run -a (gitlab-ci-linter)` is failing due to authorization required for CI lint API accesses.
+When running this command, just ignore this failed hook.
+In case you want to commit a `.gitlab-ci.yml` edition, this hook will prevent the commit creation.
+You can [skip the hooks](https://stackoverflow.com/a/7230886) with `git commit -m "msg" --no-verify`.
+This is fine for occasional `.gitlab-ci.yml` editions. In case you would like to edit this file more often and have it checked, ask a maintainer to provide you with `GITLAB_PRIVATE_TOKEN` environment variable that can be set into a shell configuration.
+With Bash, in `$HOME/.bashrc` add the following:
+```bash
+export GITLAB_PRIVATE_TOKEN=""
+```
+
+With Fish, in `$HOME/.config/fish/config.fish` add the following:
+```fish
+set -xg GITLAB_PRIVATE_TOKEN ""
+```
+Check out #169 for more details.
+
+### Black formatting
+We are using [Black](https://github.com/psf/black) formatter tool.
+Run Black on a Python file to format it:
+```bash
+poetry run black duniterpy/file.py
+```
+With `pre-commit`, Black is called on staged files, so the commit should fail in case black would make changes.
+You will have to add Black changes in order to commit your changes.
+
+### Update copyright year
+Follow [this documentation](https://github.com/Lucas-C/pre-commit-hooks#removing-old-license-and-replacing-it-with-a-new-one)
+Only difference is to update the year in `license_header.txt` rather than `LICENSE.txt`.
+
+## Release workflow
+To handle a release, you have to respect this workflow:
+
+* Verify all features and bug fixes are merged in the `dev` branch.
+* Checkout on the `dev` branch
+* Update the `CHANGELOG.md` file and commit
+* Run the `release.sh` script with the version semantic number as argument:
+
+```bash
+./release.sh 0.50.0
+```
+
+* A new commit is added with the version number and a tag in git.
+* Merge all new commits from `dev` to `master` on GitLab with a merge request.
+* Release on PyPI from the GitLab pipeline manual job of the `master` branch.
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000000000000000000000000000000000000..ef7e7efc09c9d471c391f05b9567966928085840
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,674 @@
+GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+  The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works.  By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users.  We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors.  You can apply it to
+your programs, too.
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+  All other non-permissive additional terms are considered "further
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+received it, or any part of it, contains a notice stating that it is
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+restriction, you may remove that term.  If a license document contains
+a further restriction but permits relicensing or conveying under this
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+  If you add terms to a covered work in accord with this section, you
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+additional terms that apply to those files, or a notice indicating
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+
+  Additional terms, permissive or non-permissive, may be stated in the
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+
+  8. Termination.
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+  You may not propagate or modify a covered work except as expressly
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+in a country, would infringe one or more identifiable patents in that
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+
+  A patent license is "discriminatory" if it does not include within
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+contain the covered work, unless you entered into that arrangement,
+or that patent license was granted, prior to 28 March 2007.
+
+  Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+
+  12. No Surrender of Others' Freedom.
+
+  If conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
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+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
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+
+  13. Use with the GNU Affero General Public License.
+
+  Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensed
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+combination as such.
+
+  14. Revised Versions of this License.
+
+  The Free Software Foundation may publish revised and/or new versions of
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+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
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+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
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+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
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+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
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+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    {one line to give the program's name and a brief idea of what it does.}
+    Copyright (C) {year}  {name of author}
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    {project}  Copyright (C) {year}  {fullname}
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<http://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.
diff --git a/Makefile b/Makefile
index 69d21f73e8eb1a71b5d1f6939d33dacd0429f5fc..d86e33c003be9ec41043df5b030bc5838072fb6e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,26 +1,32 @@
-.PHONY: check_format format check mypy pylint i18n_extract i18n_build tests database database_rollback database_list
+.PHONY: format check mypy pylint isort insert-license gitlab-ci-linter i18n_extract i18n_build tests database database_rollback database_list
 
 SHELL := /bin/bash
 
 format:
-	poetry run black tikka
-	poetry run black tests
-
-check_format:
-	poetry run black --check tikka
-	poetry run black --check tests
-
-check: check_format mypy pylint
+	pre-commit run -a black
 
 # check static typing
 mypy:
-	 poetry run mypy tikka --ignore-missing-imports
-	 poetry run mypy tests --ignore-missing-imports
+	pre-commit run -a mypy
 
 # check code errors
 pylint:
-	poetry run pylint --disable=C,R0902,R0903,R0904,R0912,R0913,R0914,R0915,W0613,R0901,E0401,E0601,R0201,W0703 --enable=C0121,C0202,C0321 --jobs=0 tikka/
-	poetry run pylint --disable=C,R0902,R0903,R0904,R0912,R0913,R0914,R0915,W0613,R0901,E0401,E0601,R0201,W0703 --enable=C0121,C0202,C0321 --jobs=0 tests/
+	pre-commit run -a pylint
+
+# check import sorting
+isort:
+	pre-commit run -a isort
+
+# check licence headers
+insert-license:
+	pre-commit run -a insert-license
+
+# check gitlab-ci
+gitlab-ci-linter:
+	pre-commit run -a gitlab-ci-linter
+
+# full check
+check: format mypy pylint isort insert-license
 
 i18n_update:
 	find ./tikka -type f | grep .py$$ | xargs pygettext -v --output-dir=./tikka/locale -d application;
diff --git a/bin/pylint.sh b/bin/pylint.sh
new file mode 100755
index 0000000000000000000000000000000000000000..542a864d7831a14dad5f701d5b2bbc2abc493541
--- /dev/null
+++ b/bin/pylint.sh
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+source .venv/bin/activate
+pylint --jobs=0 tikka tests
diff --git a/license_header.txt b/license_header.txt
new file mode 100644
index 0000000000000000000000000000000000000000..f7c7156220a2af3e65eeb2e136fb7e2573146571
--- /dev/null
+++ b/license_header.txt
@@ -0,0 +1,14 @@
+Copyright 2021 Vincent Texier <vit@free.fr>
+
+This software is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This software is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
diff --git a/tests/conftest.py b/tests/conftest.py
index d1652e8ec8380c90d079a9384cb488d0c99d31ff..3a4592037a03bbd4ba2cda87f06c3a8c5625db4d 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import json
 import os
 import shutil
@@ -8,8 +23,8 @@ import wx
 
 from tikka.data.account import Account
 from tikka.data.constants import DEFAULT_CONFIG_PATH
-from tikka.domains.application import Application
 from tikka.data.signing_key import TikkaSigningKey
+from tikka.domains.application import Application
 from tikka.gui.main_window import MainWindow
 
 PYTEST_TMP_FOLDER = Path("/tmp/tikka_test")
@@ -42,6 +57,11 @@ def test_folder():
 
 @pytest.fixture(name="application")
 def fixture_application():
+    """
+    Return Application instance
+
+    :return:
+    """
     return Application(PYTEST_TMP_FOLDER)
 
 
@@ -49,6 +69,7 @@ def fixture_application():
 def main_window(application):
     """
     Return Tikka MainWindow instance
+
     :return:
     """
     # create wx.App
@@ -69,21 +90,42 @@ def main_window(application):
 
 @pytest.fixture(name="mnemonic_access_code")
 def fixture_mnemonic_access_code():
+    """
+    Return MNEMONIC_ACCESS_CODE
+
+    :return:
+    """
     return MNEMONIC_ACCESS_CODE
 
 
 @pytest.fixture
 def wallet_access_code():
+    """
+    Return WALLET_ACCESS_CODE
+
+    :return:
+    """
     return WALLET_ACCESS_CODE
 
 
 @pytest.fixture
 def account(mnemonic_access_code):
+    """
+    Return Account instance from mnemonic_access_code
+
+    :param mnemonic_access_code: Mnemonic code
+    :return:
+    """
     _account = Account(TikkaSigningKey.from_dubp_mnemonic(mnemonic_access_code).pubkey)
     return _account
 
 
 @pytest.fixture
 def config_default():
+    """
+    Return default config dict
+
+    :return:
+    """
     with open(DEFAULT_CONFIG_PATH) as file_handler:
         return json.load(file_handler)
diff --git a/tests/domains/test_signing_key.py b/tests/domains/test_signing_key.py
index e7d1308ed6ccc25991e33c1f4dc37b50bf453fa1..7856ca50f1567fa222af4237d69120cd855af0b3 100644
--- a/tests/domains/test_signing_key.py
+++ b/tests/domains/test_signing_key.py
@@ -1,13 +1,28 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import base64
 from hashlib import scrypt
 from pathlib import Path
 
 from duniterpy.key.scrypt_params import ScryptParams
 
-from tikka.data.signing_key import TikkaSigningKey, DEWIF_CURRENCY_CODE_G1_TEST
+from tikka.data.signing_key import DEWIF_CURRENCY_CODE_G1_TEST, TikkaSigningKey
 
 
-def test_dubp_keypair():
+def test_dubp_keypair():  # pylint: disable=missing-function-docstring
     mnemonic = (
         "tongue cute mail fossil great frozen same social weasel impact brush kind"
     )
@@ -21,7 +36,7 @@ def test_dubp_keypair():
     assert keypair.pubkey == "732SSfuwjB7jkt9th1zerGhphs6nknaCBCTozxUcPWPU"
 
 
-def test_dewif():
+def test_dewif():  # pylint: disable=missing-function-docstring
     path = "/tmp/test.dewif"
     password = "toto titi tata"
     scrypt_params = ScryptParams()
diff --git a/tests/gui/menus/test_account_popup.py b/tests/gui/menus/test_account_popup.py
index bf86808b399ad7fac51c5f926fb00ee218e32008..501b64cc9e7c359b3a3e029bf2fe134c066cec52 100644
--- a/tests/gui/menus/test_account_popup.py
+++ b/tests/gui/menus/test_account_popup.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import wx
 from wx import MenuItem
 
@@ -5,7 +20,7 @@ from tikka.data.pubkey import PublicKey
 from tikka.gui.menus.account_popup import AccountPopupMenu
 
 
-def trigger_menu_event(menu, item):
+def trigger_menu_event(menu, item):  # pylint: disable=missing-function-docstring
     menu_event = wx.CommandEvent(wx.EVT_MENU.evtType[0], item.GetId())
     menu.ProcessEvent(menu_event)
 
@@ -28,7 +43,9 @@ def trigger_menu_event(menu, item):
 #     evt_loop.YieldFor(events_to_process)
 
 
-def test_account_popup_menu(test_folder, main_window, account):
+def test_account_popup_menu(
+    test_folder, main_window, account
+):  # pylint: disable=missing-function-docstring,unused-argument
     popup_menu = AccountPopupMenu(main_window, account)
 
     # locked account menu items
@@ -37,7 +54,7 @@ def test_account_popup_menu(test_folder, main_window, account):
 
     copy_pubkey_item = items[0]  # type: MenuItem
     unlock_account_item = items[1]  # type: MenuItem
-    delete_account_item = items[2]  # type: MenuItem
+    # delete_account_item = items[2]  # type: MenuItem
 
     wx.TheClipboard.Open()
     wx.TheClipboard.Clear()
@@ -73,7 +90,7 @@ def test_account_popup_menu(test_folder, main_window, account):
 
 def test_account_popup_menu_unlocked_account(
     test_folder, main_window, account, mnemonic_access_code
-):
+):  # pylint: disable=missing-function-docstring,unused-argument
 
     main_window.application.accounts.unlock_account(account, mnemonic_access_code)
     assert account.signing_key is not None
@@ -84,10 +101,10 @@ def test_account_popup_menu_unlocked_account(
     items = popup_menu.GetMenuItems()
     assert len(items) == 4
 
-    copy_pubkey_item = items[0]  # type: MenuItem
+    # copy_pubkey_item = items[0]  # type: MenuItem
     lock_account_item = items[1]  # type: MenuItem
     wallet_save_item = items[2]  # type: MenuItem
-    delete_account_item = items[3]  # type: MenuItem
+    # delete_account_item = items[3]  # type: MenuItem
 
     # open save wallet window
     trigger_menu_event(popup_menu, wallet_save_item)
diff --git a/tests/gui/tabs/test_account.py b/tests/gui/tabs/test_account.py
index a3face2a906ef72e83f995653a616ca8f49d278d..32b07956d8f809d6ca2b097ca3d458677b63f699 100644
--- a/tests/gui/tabs/test_account.py
+++ b/tests/gui/tabs/test_account.py
@@ -1,15 +1,34 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import builtins
+
 import wx
 
 from tikka.gui.tabs.account import AccountPanel
 
+builtins.__dict__["_"] = wx.GetTranslation
 
-def test_account_panel(test_folder, main_window, account):
 
+def test_account_panel(
+    test_folder, main_window, account
+):  # pylint: disable=missing-function-docstring,unused-argument
     main_window.application.accounts.add_account(account)
     notebook = wx.Notebook(main_window)
     notebook.SetSize((300, 300))
     account_panel = AccountPanel(notebook)
-    notebook.AddPage(account_panel, _("Account"))
+    notebook.AddPage(account_panel, _("Account"))  # pylint: disable=undefined-variable
     main_window.SetClientSize(notebook.GetBestSize())
 
     # def right_click():
diff --git a/tests/gui/windows/test_about.py b/tests/gui/windows/test_about.py
index 81cb4910e049f54c9abc10dda52812becd1c3ee1..84eda6fc4f19c6457c2848b189b9cbcc95597c03 100644
--- a/tests/gui/windows/test_about.py
+++ b/tests/gui/windows/test_about.py
@@ -1,5 +1,22 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from tikka.gui.windows.about import AboutWindow
 
 
-def test_about_window(test_folder, main_window):
+def test_about_window(
+    test_folder, main_window
+):  # pylint: disable=missing-function-docstring,unused-argument
     AboutWindow(None).Show()
diff --git a/tests/gui/windows/test_account_add.py b/tests/gui/windows/test_account_add.py
index 412ea5db9fa4a1231525f6fd042d7937b29f77c6..cd88cbc2bbff6b3dee3331ef04e5c51bf2f6ab77 100644
--- a/tests/gui/windows/test_account_add.py
+++ b/tests/gui/windows/test_account_add.py
@@ -1,12 +1,29 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from tikka.gui.windows.account_add import AddAccountWindow
 
 
-def test_account_add_window(test_folder, main_window, account):
+def test_account_add_window(
+    test_folder, main_window, account
+):  # pylint: disable=missing-function-docstring,unused-argument
     window = AddAccountWindow(main_window)
     window.Show()
 
     window.pubkey_entry.SetValue(account.pubkey)
-    window._button_ok()
+    window._button_ok()  # pylint: disable=protected-access
 
     assert main_window.application.accounts.current_account == account
     assert main_window.application.accounts.list[0] == account
diff --git a/tests/gui/windows/test_account_create.py b/tests/gui/windows/test_account_create.py
index 8520cad06276fd5b5806e4de2e2c2099479f27c2..794ea9aab3b622271b3975ae260bf8ea79fc9433 100644
--- a/tests/gui/windows/test_account_create.py
+++ b/tests/gui/windows/test_account_create.py
@@ -1,15 +1,32 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from tikka.data.pubkey import PublicKey
 from tikka.gui.windows.account_create import CreateAccountWindow
 
 
-def test_account_create_window(test_folder, main_window, account):
+def test_account_create_window(
+    test_folder, main_window, account
+):  # pylint: disable=missing-function-docstring,unused-argument
     window = CreateAccountWindow(main_window)
     window.Show()
 
-    window._generate_mnemonic_and_pubkey()
+    window._generate_mnemonic_and_pubkey()  # pylint: disable=protected-access
     pubkey = window.pubkey_value.GetValue()
 
-    window._button_ok()
+    window._button_ok()  # pylint: disable=protected-access
 
     assert pubkey == str(
         PublicKey.from_pubkey(main_window.application.accounts.current_account.pubkey)
diff --git a/tests/gui/windows/test_account_list.py b/tests/gui/windows/test_account_list.py
index cf3b9d2d56c520d4ca63043acbb9228dbccc2712..7aa0547f6114f755dfda4938747a6cdac2fa3814 100644
--- a/tests/gui/windows/test_account_list.py
+++ b/tests/gui/windows/test_account_list.py
@@ -1,11 +1,28 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import wx
+from wx.dataview import DataViewListStore
 
 from tikka.data.pubkey import PublicKey
 from tikka.gui.windows.account_list import AccountListWindow
-from wx.dataview import DataViewListStore
 
 
-def test_account_list_window_empty(test_folder, main_window):
+def test_account_list_window_empty(
+    test_folder, main_window
+):  # pylint: disable=missing-function-docstring,unused-argument
     window = AccountListWindow(main_window)
     window.Show()
 
@@ -19,7 +36,9 @@ def test_account_list_window_empty(test_folder, main_window):
     assert main_window.account_list_window is None
 
 
-def test_account_list_window(test_folder, main_window, account):
+def test_account_list_window(
+    test_folder, main_window, account
+):  # pylint: disable=missing-function-docstring,unused-argument
 
     window = AccountListWindow(main_window)
     window.Show()
diff --git a/tests/gui/windows/test_account_unlock.py b/tests/gui/windows/test_account_unlock.py
index 6f748a1e8b065ffc5282513687a556e33475ea5b..0bc7fbf1281a5059a9ea31cd0e0b85bb6962ff48 100644
--- a/tests/gui/windows/test_account_unlock.py
+++ b/tests/gui/windows/test_account_unlock.py
@@ -1,14 +1,31 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from tikka.data.pubkey import PublicKey
 from tikka.gui.windows.account_unlock import UnlockAccountWindow
 
 
-def test_account_unlock_window(test_folder, main_window, account, mnemonic_access_code):
+def test_account_unlock_window(
+    test_folder, main_window, account, mnemonic_access_code
+):  # pylint: disable=missing-function-docstring,unused-argument
     window = UnlockAccountWindow(main_window, account)
     window.Show()
     assert window.pubkey_value.GetLabel() == str(PublicKey.from_pubkey(account.pubkey))
 
     window.access_code_entry.SetValue(mnemonic_access_code)
-    window._button_ok()
+    window._button_ok()  # pylint: disable=protected-access
     assert account.signing_key is not None
 
     main_window.application.accounts.lock_account(account)
diff --git a/tests/gui/windows/test_configuration.py b/tests/gui/windows/test_configuration.py
index 4346787c6e5259099eabd77b63126982c45b800c..8237e496c04a4b9f16c89baa6c7c9039fe9fc5ac 100644
--- a/tests/gui/windows/test_configuration.py
+++ b/tests/gui/windows/test_configuration.py
@@ -1,8 +1,25 @@
-from tikka.data.constants import LANGUAGES, CURRENCIES
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from tikka.data.constants import CURRENCIES, LANGUAGES
 from tikka.gui.windows.configuration import ConfigurationWindow
 
 
-def test_configuration_window(test_folder, main_window, config_default):
+def test_configuration_window(
+    test_folder, main_window, config_default
+):  # pylint: disable=missing-function-docstring,unused-argument
     window = ConfigurationWindow(main_window, main_window.application.config)
     window.Show()
     assert window.languages_radio_box.GetSelection() == list(LANGUAGES.keys()).index(
@@ -13,11 +30,11 @@ def test_configuration_window(test_folder, main_window, config_default):
     )
 
     window.languages_radio_box.SetSelection(0)
-    window._select_language()
+    window._select_language()  # pylint: disable=protected-access
     assert main_window.application.config.get("language") == list(LANGUAGES.keys())[0]
 
     window.currencies_radio_box.SetSelection(1)
-    window._select_currency()
+    window._select_currency()  # pylint: disable=protected-access
     assert main_window.application.config.get("currency") == list(CURRENCIES.keys())[1]
 
     window.Close()
diff --git a/tests/gui/windows/test_licence.py b/tests/gui/windows/test_licence.py
index 6119bf121ed5f9d8e92f709d0f6db54aceaf48f9..101c5cda4911b9f8a28f14e0257e22f679574053 100644
--- a/tests/gui/windows/test_licence.py
+++ b/tests/gui/windows/test_licence.py
@@ -1,8 +1,25 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from tikka.data.constants import LANGUAGES
 from tikka.gui.windows.licence import LicenceWindow
 
 
-def test_licence_window(test_folder, main_window, config_default):
+def test_licence_window(
+    test_folder, main_window, config_default
+):  # pylint: disable=missing-function-docstring,unused-argument
     for language in list(LANGUAGES.keys()):
         main_window.application.config.set("language", language)
         window = LicenceWindow(main_window)
diff --git a/tests/gui/windows/test_wallet_load.py b/tests/gui/windows/test_wallet_load.py
index 6330aa59acf16c98781b3ced59a4f09902c8ea68..4771ca1d1d1aca2104ae06d4051a453ba0fe5994 100644
--- a/tests/gui/windows/test_wallet_load.py
+++ b/tests/gui/windows/test_wallet_load.py
@@ -1,13 +1,28 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from pathlib import Path
 
 from tikka.data.pubkey import PublicKey
-from tikka.gui.windows.wallet_save import WalletSaveWindow
 from tikka.gui.windows.wallet_load import WalletLoadWindow
+from tikka.gui.windows.wallet_save import WalletSaveWindow
 
 
 def test_wallet_load_window(
     test_folder, main_window, account, mnemonic_access_code, wallet_access_code
-):
+):  # pylint: disable=missing-function-docstring
     main_window.application.accounts.unlock_account(account, mnemonic_access_code)
     assert account.signing_key is not None
 
@@ -18,7 +33,7 @@ def test_wallet_load_window(
     filepath = Path(test_folder).joinpath(filename)
     window_save.path_value.SetLabel(str(filepath))
     window_save.access_code_value.SetValue(wallet_access_code)
-    window_save._click_ok()
+    window_save._click_ok()  # pylint: disable=protected-access
     assert filepath.exists() is True
 
     # load wallet window
@@ -27,11 +42,11 @@ def test_wallet_load_window(
 
     window.path_value.SetLabel(str(filepath))
     window.access_code_entry.SetValue(wallet_access_code)
-    window._unlock()
+    window._unlock()  # pylint: disable=protected-access
 
     assert window.pubkey_value.GetLabel() == str(PublicKey.from_pubkey(account.pubkey))
 
-    window._button_ok()
+    window._button_ok()  # pylint: disable=protected-access
     assert len(main_window.application.accounts.list) == 1
     assert main_window.application.accounts.current_account == account
 
diff --git a/tests/gui/windows/test_wallet_save.py b/tests/gui/windows/test_wallet_save.py
index b47b63d55c94b5948dec793daeeb77bfeee55715..17523a8a53e4f0b1faca38ac53f852de96d7084c 100644
--- a/tests/gui/windows/test_wallet_save.py
+++ b/tests/gui/windows/test_wallet_save.py
@@ -1,10 +1,27 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from pathlib import Path
 
 from tikka.data.pubkey import PublicKey
 from tikka.gui.windows.wallet_save import WalletSaveWindow
 
 
-def test_wallet_save_window(test_folder, main_window, account, mnemonic_access_code):
+def test_wallet_save_window(
+    test_folder, main_window, account, mnemonic_access_code
+):  # pylint: disable=missing-function-docstring
 
     main_window.application.accounts.unlock_account(account, mnemonic_access_code)
     assert account.signing_key is not None
@@ -23,7 +40,7 @@ def test_wallet_save_window(test_folder, main_window, account, mnemonic_access_c
         )
         filepath = Path(test_folder).joinpath(filename)
         window.path_value.SetLabel(str(filepath))
-        window._click_ok()
+        window._click_ok()  # pylint: disable=protected-access
         assert filepath.exists() is True
         filepath.unlink()
 
diff --git a/tests/libs/test_dewif.py b/tests/libs/test_dewif.py
index 830d47a4b86a071c3278ec28ba6705d387e8c682..f7d986aeeec73ab6bed44d24cf724a3b89d224ad 100644
--- a/tests/libs/test_dewif.py
+++ b/tests/libs/test_dewif.py
@@ -1,8 +1,23 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from tikka.data.signing_key import TikkaSigningKey
-from tikka.libs.dewif import DEWIF_CURRENCY_CODE_G1_TEST, Ed25519V1, Bip32Ed25519V1
+from tikka.libs.dewif import DEWIF_CURRENCY_CODE_G1_TEST, Bip32Ed25519V1, Ed25519V1
 
 
-def test_dewif_ed25519():
+def test_dewif_ed25519():  # pylint: disable=missing-function-docstring
     password = "toto titi tata"
     seed = 0xBFA3F6E322CF21D0E652F79A69DF9498FDF5347665E5646D9041F756496A1143 .to_bytes(
         32, "big"
@@ -23,7 +38,7 @@ def test_dewif_ed25519():
     assert len(bytes(dewif_instance)) == 86  # Size
 
 
-def test_dewif_bip32_ed25519():
+def test_dewif_bip32_ed25519():  # pylint: disable=missing-function-docstring
     password = "toto titi tata"
     dewif_instance = Bip32Ed25519V1(
         password,
diff --git a/tikka/__main__.py b/tikka/__main__.py
index d7e6fdb35095ffc1a91bb920c837e8de899e138f..7b4c13f3cccdfc4ef77ad73849d214d18381513e 100644
--- a/tikka/__main__.py
+++ b/tikka/__main__.py
@@ -1,12 +1,27 @@
 #!/usr/bin/env python3
 
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import logging
 
 import wx
 
 from tikka.data.constants import DATA_PATH
-from tikka.gui.main_window import MainWindow
 from tikka.domains.application import Application
+from tikka.gui.main_window import MainWindow
 
 logging.basicConfig(level=logging.DEBUG)
 
diff --git a/tikka/adapters/config.py b/tikka/adapters/config.py
index 3bb00d3c1fc2219a9746ee662eea50640f09f382..88beafcc1eb2bed2c93d90cde907f35b6224e1c0 100644
--- a/tikka/adapters/config.py
+++ b/tikka/adapters/config.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import json
 import shutil
 from pathlib import Path
diff --git a/tikka/adapters/database.py b/tikka/adapters/database.py
index 8bf1574fa6f139cafd46154c06a6b4d7443ad1bf..e8c8ff58eb28aa6e7869739e5a444f3a562e85f0 100644
--- a/tikka/adapters/database.py
+++ b/tikka/adapters/database.py
@@ -1,15 +1,30 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import json
 import logging
 import sqlite3
 from pathlib import Path
-from typing import List, Any
+from typing import Any, List
 
 from yoyo import get_backend, read_migrations
 
 from tikka.data.constants import (
+    CURRENCIES,
     DATABASE_FILE_EXTENSION,
     DATABASE_MIGRATIONS_PATH,
-    CURRENCIES,
 )
 
 
@@ -58,7 +73,7 @@ class Database:
         # Creating a cursor object using the cursor() method
         cursor = self.connection.cursor()
         fields_string = ",".join(kwargs.keys())
-        values_string = ",".join(["?" for _ in range(len(kwargs.keys()))])
+        values_string = ",".join(["?" for _ in range(len(kwargs))])
         filtered_values = list()
         for value in kwargs.values():
             # serialize dict to json string
diff --git a/tikka/adapters/wallets.py b/tikka/adapters/wallets.py
index 5c67951e7b1d4d0da9a55f64d551ccf6f20371e3..403a112a3d11dd2a765e17eb3cd207b23f123fea 100644
--- a/tikka/adapters/wallets.py
+++ b/tikka/adapters/wallets.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from pathlib import Path
 from typing import Optional
 
@@ -61,9 +76,10 @@ class Wallet:
         :param password: Password to open the file (default=None)
         :return:
         """
+        if password is None:
+            return False
         if self.type == "EWIF":
-            if password is None:
-                return False
+
             signing_key = TikkaSigningKey.from_ewif_file(
                 str(self.path), password
             )  # type: TikkaSigningKey
@@ -76,10 +92,11 @@ class Wallet:
 
 class Wallets:
     """
-    Class to deal with hard wallets
+    Class to deal with file wallets
     """
 
-    def get(self, path: str, password: Optional[str] = None) -> Wallet:
+    @staticmethod
+    def get(path: str, password: Optional[str] = None) -> Wallet:
         """
         Return WalletFile instance
 
diff --git a/tikka/data/account.py b/tikka/data/account.py
index 76ba276419bdce7d521ccda3ac3778e398d17d71..5ce2ea41b62e9eb43928ce40ee9d9251bb7bda99 100644
--- a/tikka/data/account.py
+++ b/tikka/data/account.py
@@ -1,6 +1,20 @@
-from typing import TypeVar, Optional
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from dataclasses import dataclass
+from typing import Optional, TypeVar
 
 from tikka.data.pubkey import PublicKey
 from tikka.data.signing_key import TikkaSigningKey
@@ -22,18 +36,40 @@ class Account:
 
     @property
     def signing_key(self) -> Optional[TikkaSigningKey]:
+        """
+        SigningKey instance getter
+
+        :return:
+        """
         return self._signing_key
 
     @signing_key.setter
     def signing_key(self, signing_key: TikkaSigningKey):
+        """
+        SigningKey instance setter
+
+        :param signing_key: SigningKey instance
+        :return:
+        """
         self._signing_key = signing_key
 
     @property
     def entropy(self) -> Optional[bytearray]:
+        """
+        entropy getter
+
+        :return:
+        """
         return self._entropy
 
     @entropy.setter
     def entropy(self, entropy: bytearray):
+        """
+        entropy setter
+
+        :param entropy: Entropy as bytes
+        :return:
+        """
         self._entropy = entropy
 
     def __str__(self):
@@ -56,3 +92,6 @@ class Account:
         if not isinstance(other, self.__class__):
             return False
         return other.pubkey == self.pubkey
+
+    def __hash__(self):
+        return self.pubkey
diff --git a/tikka/data/constants.py b/tikka/data/constants.py
index ccda86664271a819422b22668a31f64abd393f13..78f246f139906768586630fbcf2835573b48ab4b 100644
--- a/tikka/data/constants.py
+++ b/tikka/data/constants.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from collections import OrderedDict
 from pathlib import Path
 
diff --git a/tikka/data/pubkey.py b/tikka/data/pubkey.py
index 1f5d49f262df1308455f42d54e6777d37730d104..c86af768e7a1742690b1044ab3c5152c759831d6 100644
--- a/tikka/data/pubkey.py
+++ b/tikka/data/pubkey.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import hashlib
 import re
 from typing import Type, TypeVar
@@ -128,11 +143,14 @@ class PublicKey:
         if not isinstance(other, PublicKey):
             return False
 
-        if self.base58 == other.base58 and self.checksum == other.checksum:
+        if self.base58 == other.base58:
             return True
 
         return False
 
+    def __hash__(self):
+        return self.base58
+
 
 class PubkeyNotValid(Exception):
     pass
diff --git a/tikka/data/signing_key.py b/tikka/data/signing_key.py
index 4c713e231fa645c62cbcb3f0131467b9b9d5cd81..6bca7598932a6487778126b8da756f1af8848e04 100644
--- a/tikka/data/signing_key.py
+++ b/tikka/data/signing_key.py
@@ -1,13 +1,27 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import hashlib
 import struct
 from os import PathLike
-from typing import Union, TypeVar
+from typing import TypeVar, Union
 
 from duniterpy.key import SigningKey
 from duniterpy.key.scrypt_params import ScryptParams
 from pyaes import AESModeOfOperationECB
 
-
 DEWIF_CURRENCY_CODE_NONE = 0x00000000
 DEWIF_CURRENCY_CODE_G1 = 0x00000001
 DEWIF_CURRENCY_CODE_G1_TEST = 0x10000001
diff --git a/tikka/domains/accounts.py b/tikka/domains/accounts.py
index d3a64c861bd2229404386a5f073dbac21de749a3..ef841c375c5c4cea55392b3950669c3c546ced1e 100644
--- a/tikka/domains/accounts.py
+++ b/tikka/domains/accounts.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import logging
 from pathlib import Path
 from typing import Optional
@@ -5,8 +20,8 @@ from typing import Optional
 from mnemonic import Mnemonic
 
 from tikka.adapters.database import Database
-from tikka.adapters.wallets import Wallets, Wallet
-from tikka.data.account import Account, TABLE_NAME
+from tikka.adapters.wallets import Wallet, Wallets
+from tikka.data.account import TABLE_NAME, Account
 from tikka.data.constants import MNEMONIC_LANGUAGES
 from tikka.data.pubkey import PublicKey
 from tikka.data.signing_key import TikkaSigningKey
diff --git a/tikka/domains/application.py b/tikka/domains/application.py
index d55026e7323adee93d64cc09401dbbc4960b0ef3..20269c61bcd7ed6c6d401c2f2b02f7edd8992252 100644
--- a/tikka/domains/application.py
+++ b/tikka/domains/application.py
@@ -1,9 +1,24 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import gettext
 from pathlib import Path
 
-from tikka.adapters.wallets import Wallets
-from tikka.adapters.database import Database
 from tikka.adapters.config import Config
+from tikka.adapters.database import Database
+from tikka.adapters.wallets import Wallets
 from tikka.domains.accounts import Accounts
 
 
diff --git a/tikka/gui/images/images.py b/tikka/gui/images/images.py
index f418abdd5db8f13399101fc8b386de5fe3d12482..383985f1282a459e4eaee2a5f912d40fdf649989 100644
--- a/tikka/gui/images/images.py
+++ b/tikka/gui/images/images.py
@@ -1,8 +1,22 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 from pathlib import Path
 
 import wx
 
-
 # images index
 logo = ("logo_tikka_01.jpeg", wx.BITMAP_TYPE_JPEG)
 safe = ("safe_400x400.png", wx.BITMAP_TYPE_PNG)
@@ -18,6 +32,13 @@ config_symbol = ("config_symbol.png", wx.BITMAP_TYPE_PNG)
 
 
 def load(image_attributes: tuple) -> wx.Image:
+    """
+    Load image file in wxPython
+
+    :param image_attributes: (filename, type)
+
+    :return:
+    """
     filename, _type = image_attributes
 
     image = wx.Image(
diff --git a/tikka/gui/main_window.py b/tikka/gui/main_window.py
index 4b06feff264297d7a7861a1d210e8e811c19e607..25557f647748bc450bd7d355e878e0f60c2e0a3c 100644
--- a/tikka/gui/main_window.py
+++ b/tikka/gui/main_window.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
 import sys
 from typing import TYPE_CHECKING
@@ -5,16 +20,15 @@ from typing import TYPE_CHECKING
 import wx
 
 from tikka import __version__
-
 from tikka.data.account import Account
 from tikka.data.constants import CURRENCIES
-from tikka.gui.tabs.account import AccountPanel
-from tikka.gui.menus.menubar import MenuBar
 from tikka.domains.application import Application
+from tikka.gui.menus.menubar import MenuBar
+from tikka.gui.tabs.account import AccountPanel
 from tikka.gui.tabs.identity import IdentityPanel
 
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 builtins.__dict__["_"] = wx.GetTranslation
 
@@ -54,7 +68,9 @@ class MainWindow(wx.Frame):
         if self.application.accounts.current_account:
             self.account_panel.set_account(self.application.accounts.current_account)
         self.identity_panel = IdentityPanel(self.notebook)
-        self.notebook.AddPage(self.account_panel, _("Account"))
+        self.notebook.AddPage(
+            self.account_panel, _("Account")  # pylint: disable=used-before-assignment
+        )
         self.notebook.AddPage(self.identity_panel, _("Identity"))
         self.notebook.SetSelection(0)
 
diff --git a/tikka/gui/menus/account_popup.py b/tikka/gui/menus/account_popup.py
index 1df82239df8438f5b3f4939a30a9ab05d11eb57e..62c3a37c76e2294e1276e29b1f395badf2c0e90b 100644
--- a/tikka/gui/menus/account_popup.py
+++ b/tikka/gui/menus/account_popup.py
@@ -1,5 +1,20 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
-from typing import TypeVar, TYPE_CHECKING
+from typing import TYPE_CHECKING, TypeVar
 
 import wx
 
@@ -10,8 +25,9 @@ from tikka.gui.windows.wallet_load import WalletLoadWindow
 from tikka.gui.windows.wallet_save import WalletSaveWindow
 
 if TYPE_CHECKING:
+    import _  # pylint: disable=import-error
+
     from tikka.gui.main_window import MainWindow
-    import _
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -36,7 +52,11 @@ class AccountPopupMenu(wx.Menu):
         self.main_window = main_window
         self.confirm_dialog = None
 
-        item = wx.MenuItem(self, wx.Window.NewControlId(), _("Copy public key"))
+        item = wx.MenuItem(
+            self,
+            wx.Window.NewControlId(),
+            _("Copy public key"),  # pylint: disable=used-before-assignment
+        )
         self.Append(item)
         self.Bind(
             wx.EVT_MENU, lambda event: self._copy_pubkey_to_clipboard(account), item
diff --git a/tikka/gui/menus/accounts.py b/tikka/gui/menus/accounts.py
index a40ebb46be6204d17f2ef2c7e99b691173987387..ed6b4fce25c2db38bbd106b7d5fddf3eefe26afc 100644
--- a/tikka/gui/menus/accounts.py
+++ b/tikka/gui/menus/accounts.py
@@ -1,6 +1,22 @@
-import wx
-from typing import TYPE_CHECKING, TypeVar
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
+from typing import TYPE_CHECKING, TypeVar
+
+import wx
 
 from tikka.data.constants import DATA_PATH
 from tikka.domains.application import Application
@@ -13,7 +29,7 @@ if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 builtins.__dict__["_"] = wx.GetTranslation
 
@@ -34,7 +50,9 @@ class AccountsMenu(wx.Menu):
         # The "\t..." syntax defines an accelerator key that also triggers
         # the same event
         account_list_item = self.Append(
-            -1, _("&Account list\tCtrl-L"), _("Open the account list")
+            -1,
+            _("&Account list\tCtrl-L"),  # pylint: disable=used-before-assignment
+            _("Open the account list"),
         )
         self.AppendSeparator()
         add_account_item = self.Append(
diff --git a/tikka/gui/menus/help.py b/tikka/gui/menus/help.py
index a1b41661ccbbcbb994bd1a212422662c9712379d..df859fa8dea3b237e4a63d56a795160883814e56 100644
--- a/tikka/gui/menus/help.py
+++ b/tikka/gui/menus/help.py
@@ -1,6 +1,22 @@
-import wx
-from typing import TYPE_CHECKING, TypeVar
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
+from typing import TYPE_CHECKING, TypeVar
+
+import wx
 
 from tikka.data.constants import DATA_PATH
 from tikka.domains.application import Application
@@ -12,7 +28,7 @@ if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 builtins.__dict__["_"] = wx.GetTranslation
 
@@ -32,7 +48,11 @@ class HelpMenu(wx.Menu):
 
         # The "\t..." syntax defines an accelerator key that also triggers
         # the same event
-        licence_item = self.Append(-1, _("&Ğ1 licence"), _("Display the Ğ1 Licence"))
+        licence_item = self.Append(
+            -1,
+            _("&Ğ1 licence"),  # pylint: disable=used-before-assignment
+            _("Display the Ğ1 Licence"),
+        )
         configuration_item = self.Append(
             -1, _("&Configuration"), _("Open the configuration window")
         )
diff --git a/tikka/gui/menus/menubar.py b/tikka/gui/menus/menubar.py
index 4e7833f4233eaa02c8655538e3632786c5f66b81..9e908d4612e386d2c7192245b47a3e1d3fa36444 100644
--- a/tikka/gui/menus/menubar.py
+++ b/tikka/gui/menus/menubar.py
@@ -1,18 +1,33 @@
-import wx
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
+from typing import TYPE_CHECKING, TypeVar
+
+import wx
 
 from tikka.data.constants import DATA_PATH
 from tikka.domains.application import Application
 from tikka.gui.menus.accounts import AccountsMenu
-from typing import TYPE_CHECKING, TypeVar
-
 from tikka.gui.menus.help import HelpMenu
 
 if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 builtins.__dict__["_"] = wx.GetTranslation
 
@@ -28,7 +43,10 @@ class MenuBar(wx.MenuBar):
         """
         super().__init__()
 
-        self.Append(AccountsMenu(main_window), _("&Accounts"))
+        self.Append(
+            AccountsMenu(main_window),
+            _("&Accounts"),  # pylint: disable=used-before-assignment
+        )
         self.Append(HelpMenu(main_window), _("&Help"))
 
 
diff --git a/tikka/gui/tabs/account.py b/tikka/gui/tabs/account.py
index 9cec09a7da0553d444aae2ecceb273475f4b0858..9ad63ca55619f13f7196d0863105e929f87784e6 100644
--- a/tikka/gui/tabs/account.py
+++ b/tikka/gui/tabs/account.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
 from typing import TYPE_CHECKING, Optional
 
@@ -9,7 +24,7 @@ from tikka.gui.images import images
 from tikka.gui.menus.account_popup import AccountPopupMenu
 
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 builtins.__dict__["_"] = wx.GetTranslation
 
@@ -142,7 +157,9 @@ if __name__ == "__main__":
     main_window_ = MockMainWindow(None, application=app)
     notebook = wx.Notebook(main_window_)
     account_panel = AccountPanel(notebook)
-    notebook.AddPage(account_panel, _("Account"))
+    notebook.AddPage(
+        account_panel, _("Account")  # pylint: disable=used-before-assignment
+    )
     main_window_.SetClientSize(notebook.GetBestSize())
     main_window_.Show()
 
diff --git a/tikka/gui/tabs/identity.py b/tikka/gui/tabs/identity.py
index 2a5a0b820289ec09345db805ea451215c7d8b592..7e716a04b69c045fd09c7318336573346b6e7ac1 100644
--- a/tikka/gui/tabs/identity.py
+++ b/tikka/gui/tabs/identity.py
@@ -1,5 +1,19 @@
-import builtins
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import builtins
 from typing import TYPE_CHECKING
 
 import wx
@@ -7,7 +21,7 @@ import wx
 from tikka.data.account import Account
 
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 builtins.__dict__["_"] = wx.GetTranslation
 
@@ -19,7 +33,9 @@ class IdentityPanel(wx.Panel):
         default_font = self.GetFont()
         default_bold_font = default_font.Bold()
 
-        uid_label = wx.StaticText(self, label=_("Nickname"))
+        uid_label = wx.StaticText(
+            self, label=_("Nickname")  # pylint: disable=used-before-assignment
+        )
         uid_label.SetFont(default_bold_font)
         self.uid = wx.StaticText(self, label="Not implemented")
 
diff --git a/tikka/gui/widgets/password.py b/tikka/gui/widgets/password.py
index c31222ca953a3615ea266b6dcdcfc87d84bb5091..065d7f405540f536a0085ea118e4f350efc6a7f0 100644
--- a/tikka/gui/widgets/password.py
+++ b/tikka/gui/widgets/password.py
@@ -1,4 +1,17 @@
-from typing import Optional, Callable
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import wx
 
@@ -53,11 +66,11 @@ class PasswordCtrl(wx.Panel):
 
         return self.clear_password_entry.GetValue()
 
-    def ToggleHiddenMode(self, event: Optional[wx.Event] = None):
+    def ToggleHiddenMode(self):
         """
         Toggle hidden password mode
 
-        :param event:
+        :param _: dummy event
         :return:
         """
         self.password_hidden = not self.password_hidden
@@ -98,10 +111,10 @@ if __name__ == "__main__":
         wx.EVT_KEY_DOWN, lambda event: print(event.GetKeyCode(), event.GetRawKeyCode())
     )
 
-    sizer = wx.BoxSizer()
-    sizer.Add(password)
-    sizer.Add(toggle_button, wx.EXPAND)
-    main_window.SetSizer(sizer)
+    sizer_ = wx.BoxSizer()
+    sizer_.Add(password)
+    sizer_.Add(toggle_button, wx.EXPAND)
+    main_window.SetSizer(sizer_)
 
     main_window.Show()
     # start gui event loop
diff --git a/tikka/gui/windows/about.py b/tikka/gui/windows/about.py
index 8a0ad34a3d39bbcf5aa3faaeb6e34e8f5f449722..a89446db8abc4af483bfdf0f3a5fd9ab038c25ec 100644
--- a/tikka/gui/windows/about.py
+++ b/tikka/gui/windows/about.py
@@ -1,14 +1,30 @@
-import wx
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
+from typing import TYPE_CHECKING, Optional, TypeVar
 
-from typing import TYPE_CHECKING, TypeVar, Optional
+import wx
 
 from tikka import __version__
 from tikka.gui.images import images
 
 if TYPE_CHECKING:
+    import _  # pylint: disable=import-error
+
     from tikka.gui.main_window import MainWindow
-    import _
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -24,7 +40,7 @@ class AboutWindow(wx.Frame):
         """
         super().__init__(parent)
 
-        self.SetTitle(_("About"))
+        self.SetTitle(_("About"))  # pylint: disable=used-before-assignment
         self.SetBackgroundColour("white")
 
         default_font = self.GetFont()
diff --git a/tikka/gui/windows/account_add.py b/tikka/gui/windows/account_add.py
index 4a583d9cea8aae3e9575ddf6b536e057d84a9109..f7ebb2a0b004d2e00b966d64577341a20ea960fc 100644
--- a/tikka/gui/windows/account_add.py
+++ b/tikka/gui/windows/account_add.py
@@ -1,18 +1,33 @@
-import wx
-import builtins
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import builtins
 from typing import TYPE_CHECKING, TypeVar
 
+import wx
+
 from tikka.data.account import Account
 from tikka.data.constants import DATA_PATH
-from tikka.data.pubkey import PublicKey, PubkeyChecksumNotValid, PubkeyNotValid
+from tikka.data.pubkey import PubkeyChecksumNotValid, PubkeyNotValid, PublicKey
 from tikka.domains.application import Application
 from tikka.gui.images import images
 
 if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -28,7 +43,7 @@ class AddAccountWindow(wx.Frame):
         """
         super().__init__(parent)
 
-        self.SetTitle(_("Add account"))
+        self.SetTitle(_("Add account"))  # pylint: disable=used-before-assignment
 
         self.pubkey = None
 
diff --git a/tikka/gui/windows/account_create.py b/tikka/gui/windows/account_create.py
index 3222243ad935735cc382ea46e748f68685355789..6acd87741f0d456d8a33a3874283f1afc58f36f3 100644
--- a/tikka/gui/windows/account_create.py
+++ b/tikka/gui/windows/account_create.py
@@ -1,20 +1,35 @@
-import wx
-import builtins
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import builtins
 from typing import TYPE_CHECKING, TypeVar
 
+import wx
+
 from tikka.data.account import Account
-from tikka.data.constants import DATA_PATH, ACCESS_TYPE_MNEMONIC
+from tikka.data.constants import ACCESS_TYPE_MNEMONIC, DATA_PATH
 from tikka.data.pubkey import PublicKey
-from tikka.libs.secret import generate_mnemonic
-from tikka.domains.application import Application
 from tikka.data.signing_key import TikkaSigningKey
+from tikka.domains.application import Application
 from tikka.gui.images import images
+from tikka.libs.secret import generate_mnemonic
 
 if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -30,7 +45,7 @@ class CreateAccountWindow(wx.Frame):
         """
         super().__init__(parent)
 
-        self.SetTitle(_("Create account"))
+        self.SetTitle(_("Create account"))  # pylint: disable=used-before-assignment
 
         default_font = self.GetFont()
         default_bold_font = default_font.Bold()
diff --git a/tikka/gui/windows/account_list.py b/tikka/gui/windows/account_list.py
index 8e95d56d85841058901daea3f6943a401aabe9a3..1bd3f129f349a596263e7bba28973af1a3abef76 100644
--- a/tikka/gui/windows/account_list.py
+++ b/tikka/gui/windows/account_list.py
@@ -1,11 +1,24 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
+from typing import TYPE_CHECKING, TypeVar
 
 import wx
 from wx import dataview
 
-from typing import TYPE_CHECKING, TypeVar
-
-
 from tikka.data.account import Account
 from tikka.data.constants import DATA_PATH
 from tikka.data.pubkey import PublicKey
@@ -16,7 +29,7 @@ from tikka.gui.menus.account_popup import AccountPopupMenu
 if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -32,7 +45,7 @@ class AccountListWindow(wx.Frame):
         """
         super().__init__(parent)
 
-        self.SetTitle(_("Account list"))
+        self.SetTitle(_("Account list"))  # pylint: disable=used-before-assignment
         self.SetSize(600, 300)
 
         locked_image = images.load(images.locked)
@@ -69,7 +82,7 @@ class AccountListWindow(wx.Frame):
         self.account_listctrl.Bind(
             wx.EVT_LEFT_DCLICK, lambda event: self._select_item()
         )
-        self.Bind(wx.EVT_CLOSE, self._close, self)
+        self.Bind(wx.EVT_CLOSE, lambda event: self._close(), self)
 
         # expose listbox window instance in main window
         self.GetParent().account_list_window = self  # type: ignore
@@ -116,11 +129,10 @@ class AccountListWindow(wx.Frame):
         # show popup menu
         self.account_listctrl.PopupMenu(popup_menu)
 
-    def _close(self, event: wx.CloseEvent):
+    def _close(self):
         """
         CloseEvent handler
 
-        :param event: CloseEvent instance
         :return:
         """
         # tell main_window
diff --git a/tikka/gui/windows/account_unlock.py b/tikka/gui/windows/account_unlock.py
index d9eaf128a4c87020386f2da30b9b61c54913d462..1cdfd7b9b04100bca3c644359d5b153df83732b9 100644
--- a/tikka/gui/windows/account_unlock.py
+++ b/tikka/gui/windows/account_unlock.py
@@ -1,12 +1,26 @@
-import builtins
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import wx
+import builtins
 import logging
-
 from typing import TYPE_CHECKING, TypeVar
 
+import wx
+
 from tikka.data.account import Account
-from tikka.data.constants import DATA_PATH, ACCESS_TYPE_MNEMONIC, ACCESS_TYPE_CLASSIC
+from tikka.data.constants import ACCESS_TYPE_CLASSIC, ACCESS_TYPE_MNEMONIC, DATA_PATH
 from tikka.data.pubkey import PublicKey
 from tikka.domains.application import Application
 from tikka.gui.images import images
@@ -15,7 +29,7 @@ from tikka.gui.widgets.password import PasswordCtrl
 if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -32,7 +46,9 @@ class UnlockAccountWindow(wx.Frame):
         """
         super().__init__(parent)
 
-        self.SetTitle(_("Unlock account access"))
+        self.SetTitle(
+            _("Unlock account access")  # pylint: disable=used-before-assignment
+        )
 
         default_font = self.GetFont()
         default_bold_font = default_font.Bold()
diff --git a/tikka/gui/windows/configuration.py b/tikka/gui/windows/configuration.py
index 82fa1ae19a5370465515431a8ffb68690ee8cb53..b3fd49fbfa53602fc18c7ba1bc1075643898f378 100644
--- a/tikka/gui/windows/configuration.py
+++ b/tikka/gui/windows/configuration.py
@@ -1,18 +1,32 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
+from typing import TYPE_CHECKING, TypeVar
 
 import wx
 
-from typing import TYPE_CHECKING, TypeVar
-
 from tikka.adapters.config import Config
-from tikka.data.constants import LANGUAGES, CURRENCIES, DATA_PATH
+from tikka.data.constants import CURRENCIES, DATA_PATH, LANGUAGES
 from tikka.domains.application import Application
 from tikka.gui.images import images
 
 if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -32,7 +46,7 @@ class ConfigurationWindow(wx.Frame):
         # access to config adapter
         self.config_ = config
 
-        self.SetTitle(_("Configuration"))
+        self.SetTitle(_("Configuration"))  # pylint: disable=used-before-assignment
 
         default_font = self.GetFont()
         default_italic_font = default_font.Italic()
diff --git a/tikka/gui/windows/licence.py b/tikka/gui/windows/licence.py
index bdbf541e003cb247d7dfc1d17ea80d1dc22b447c..4da9002e40b57a09d70e17a0c0c1cf8817d6477d 100644
--- a/tikka/gui/windows/licence.py
+++ b/tikka/gui/windows/licence.py
@@ -1,10 +1,23 @@
-import builtins
-
-import wx
-import markdown
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import builtins
 from typing import TYPE_CHECKING, TypeVar
 
+import markdown
+import wx
 from wx.html import HtmlWindow
 
 from tikka.data.constants import DATA_PATH
@@ -13,7 +26,7 @@ from tikka.domains.application import Application
 if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -29,7 +42,7 @@ class LicenceWindow(wx.Frame):
         """
         super().__init__(parent)
 
-        self.SetTitle(_("Ğ1 licence"))
+        self.SetTitle(_("Ğ1 licence"))  # pylint: disable=used-before-assignment
         self.SetSize((800, 600))
 
         with open(
diff --git a/tikka/gui/windows/wallet_load.py b/tikka/gui/windows/wallet_load.py
index d32282653f6568dba9d22486fa3ab2c8f5a32acf..65560d2c3003d420b3809ffd75fbc2aeba4737f0 100644
--- a/tikka/gui/windows/wallet_load.py
+++ b/tikka/gui/windows/wallet_load.py
@@ -1,9 +1,23 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import builtins
+from typing import TYPE_CHECKING, TypeVar
 
 import wx
 
-from typing import TYPE_CHECKING, TypeVar
-
 from tikka.data.constants import DATA_PATH
 from tikka.data.pubkey import PublicKey
 from tikka.domains.application import Application
@@ -14,7 +28,7 @@ if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -33,7 +47,9 @@ class WalletLoadWindow(wx.Frame):
         # variables
         self.wallet = None
 
-        self.SetTitle(_("Load wallet from disk"))
+        self.SetTitle(
+            _("Load wallet from disk")  # pylint: disable=used-before-assignment
+        )
 
         default_font = self.GetFont()
         default_bold_font = default_font.Bold()
diff --git a/tikka/gui/windows/wallet_save.py b/tikka/gui/windows/wallet_save.py
index 54816c222666f602970a980fb17529a4acd1da90..bfb7cb08254a7184fe7e7a56e05c86a9da5bc5e4 100644
--- a/tikka/gui/windows/wallet_save.py
+++ b/tikka/gui/windows/wallet_save.py
@@ -1,19 +1,34 @@
-import wx
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from typing import TYPE_CHECKING, TypeVar
 
+import wx
+
 from tikka.data.account import Account
 from tikka.data.constants import DATA_PATH
 from tikka.data.pubkey import PublicKey
-from tikka.libs.secret import generate_alphabetic
 from tikka.domains.application import Application
 from tikka.gui.images import images
+from tikka.libs.secret import generate_alphabetic
 
 if TYPE_CHECKING or __name__ == "__main__":
     from tikka.gui.main_window import MainWindow
 
 if TYPE_CHECKING:
-    import _
+    import _  # pylint: disable=import-error
 
 MainWindowType = TypeVar("MainWindowType", bound="MainWindow")
 
@@ -30,15 +45,17 @@ class WalletSaveWindow(wx.Frame):
 
         self.account = account
 
-        self.SetTitle(_("Save wallet to disk"))
+        self.SetTitle(
+            _("Save wallet to disk")  # pylint: disable=used-before-assignment
+        )
 
         default_font = self.GetFont()
         default_bold_font = default_font.Bold()
 
         # images
-        disk_image = images.load(images.keys)
-        disk_image.Rescale(200, 200, wx.IMAGE_QUALITY_HIGH)
-        keys_bitmap = wx.StaticBitmap(self, -1, disk_image.ConvertToBitmap())
+        keys_image = images.load(images.keys)
+        keys_image.Rescale(200, 200, wx.IMAGE_QUALITY_HIGH)
+        keys_bitmap = wx.StaticBitmap(self, -1, keys_image.ConvertToBitmap())
 
         arrow_right_image = images.load(images.arrow_right)
         arrow_right_image.Rescale(200, 200, wx.IMAGE_QUALITY_HIGH)
diff --git a/tikka/libs/dewif.py b/tikka/libs/dewif.py
index 67eb8e7a2d48d4d90d0ca7656ca1a343a11cd542..ab2abee0715d6bcab98c9668a5cd4d16dd1c1c3d 100644
--- a/tikka/libs/dewif.py
+++ b/tikka/libs/dewif.py
@@ -1,15 +1,29 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 """
 Dewif lib module
 """
 import base64
 import hashlib
 import random
-
-from mnemonic import Mnemonic
 import struct
-
 from dataclasses import dataclass
+
 from duniterpy.key.scrypt_params import ScryptParams
+from mnemonic import Mnemonic
 
 DEWIF_CURRENCY_CODE_NONE = 0x00000000
 DEWIF_CURRENCY_CODE_G1 = 0x00000001
@@ -49,16 +63,16 @@ def byte_xor(bytes1, bytes2):
     return bytes([_a ^ _b for _a, _b in zip(bytes1, bytes2)])
 
 
-def scrypt_maxmem(n, r, p):
+def scrypt_maxmem(n_value, r_value, p_value):
     """
     Get sufficient maxmem scrypt parameter
 
-    :param n: N value
-    :param r: r value
-    :param p: p value
+    :param n_value: N value
+    :param r_value: r value
+    :param p_value: p value
     :return:
     """
-    return 128 * r * (n + p + 2)
+    return 128 * r_value * (n_value + p_value + 2)
 
 
 @dataclass
@@ -71,7 +85,7 @@ class DewifV1:
     currency: int
     log_n: int
 
-    VERSION = 1
+    version = 1
 
     def __bytes__(self) -> bytes:
         raise NotImplementedError
@@ -92,7 +106,7 @@ class Ed25519V1(DewifV1):
     seed: bytes
     pubkey: bytes
 
-    ALGORITHM = DEWIF_ALGORITHM_CODE_ED25519
+    algorithm = DEWIF_ALGORITHM_CODE_ED25519
 
     def __bytes__(self):
         nonce = random_bytes(12)
@@ -100,11 +114,11 @@ class Ed25519V1(DewifV1):
         # # test RFC
         # nonce = 0x013194f1286512cf094295cb.to_bytes(12, "big")
 
-        header = struct.pack(">ii", self.VERSION, self.currency)
+        header = struct.pack(">ii", self.version, self.currency)
         data = (
             header
             + self.log_n.to_bytes(1, "big")
-            + self.ALGORITHM.to_bytes(1, "big")
+            + self.algorithm.to_bytes(1, "big")
             + nonce
         )
 
@@ -140,7 +154,7 @@ class Bip32Ed25519V1(DewifV1):
     mnemonic: str
     language: str
 
-    ALGORITHM = DEWIF_ALGORITHM_CODE_BIP32_ED25519
+    algorithm = DEWIF_ALGORITHM_CODE_BIP32_ED25519
 
     def __bytes__(self):
         nonce = random_bytes(12)
@@ -148,11 +162,11 @@ class Bip32Ed25519V1(DewifV1):
         # test RFC
         # nonce = 0xc54299ae71fe2a4ecdc7d58a.to_bytes(12, "big")
 
-        header = struct.pack(">ii", self.VERSION, self.currency)
+        header = struct.pack(">ii", self.version, self.currency)
         data = (
             header
             + self.log_n.to_bytes(1, "big")
-            + self.ALGORITHM.to_bytes(1, "big")
+            + self.algorithm.to_bytes(1, "big")
             + nonce
         )
 
diff --git a/tikka/libs/secret.py b/tikka/libs/secret.py
index af656b6c7858dc624a5bd55f1a86f3ee8a312177..11080bd68e9100a299e5141796393a6ca5ec9a3e 100644
--- a/tikka/libs/secret.py
+++ b/tikka/libs/secret.py
@@ -1,3 +1,18 @@
+# Copyright 2021 Vincent Texier <vit@free.fr>
+#
+# This software is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This software is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 import random
 import string