diff --git a/lib/ucoinpy/documents/__init__.py b/lib/ucoinpy/documents/__init__.py
index 198b62b474c770b7440a0ac72c8d2d8d14eb61f7..9763c366155f445dd55be9022f8d2cacf381036a 100644
--- a/lib/ucoinpy/documents/__init__.py
+++ b/lib/ucoinpy/documents/__init__.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 3 déc. 2014
 
 @author: inso
-'''
+"""
 import base58
 import base64
 import re
@@ -23,10 +23,10 @@ class Document:
             self.signatures = []
 
     def sign(self, keys):
-        '''
+        """
         Sign the current document.
         Warning : current signatures will be replaced with the new ones.
-        '''
+        """
         self.signatures = []
         for key in keys:
             signing = base64.b64encode(key.signature(bytes(self.raw(), 'ascii')))
@@ -34,10 +34,10 @@ class Document:
             self.signatures.append(signing.decode("ascii"))
 
     def signed_raw(self):
-        '''
+        """
         If keys are None, returns the raw + current signatures
         If keys are present, returns the raw signed by these keys
-        '''
+        """
         raw = self.raw()
         signed = "\n".join(self.signatures)
         signed_raw = raw + signed + "\n"
diff --git a/lib/ucoinpy/documents/block.py b/lib/ucoinpy/documents/block.py
index dd17cb2f7e52f772c422eb4b93a3618943ddb29a..a02a550dac8f71302bf3140503ceae7c98a40bd6 100644
--- a/lib/ucoinpy/documents/block.py
+++ b/lib/ucoinpy/documents/block.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 2 déc. 2014
 
 @author: inso
-'''
+"""
 
 from .. import PROTOCOL_VERSION
 from . import Document
@@ -15,7 +15,7 @@ import logging
 
 
 class Block(Document):
-    '''
+    """
 Version: VERSION
 Type: Block
 Currency: CURRENCY
@@ -52,7 +52,7 @@ Transactions:
 COMPACT_TRANSACTION
 ...
 BOTTOM_SIGNATURE
-    '''
+    """
 
     re_type = re.compile("Type: (Block)\n")
     re_noonce = re.compile("Nonce: ([0-9]+)\n")
@@ -82,9 +82,9 @@ BOTTOM_SIGNATURE
                  parameters, members_count, identities, joiners,
                  actives, leavers, excluded, certifications,
                  transactions, signature):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(version, currency, [signature])
         self.noonce = noonce
         self.number = number
diff --git a/lib/ucoinpy/documents/certification.py b/lib/ucoinpy/documents/certification.py
index 3792839e593b9f46c2078b91fe867bad586192ac..d7e79adb550dcc1ce15c10dc20fa7e0629c40758 100644
--- a/lib/ucoinpy/documents/certification.py
+++ b/lib/ucoinpy/documents/certification.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 2 déc. 2014
 
 @author: inso
-'''
+"""
 import re
 import base64
 import logging
@@ -11,9 +11,9 @@ from . import Document
 
 
 class SelfCertification(Document):
-    '''
+    """
     A document discribing a self certification.
-    '''
+    """
 
     re_inline = re.compile("([1-9A-Za-z][^OIl]{42,45}):([A-Za-z0-9+/]+(?:=|==)?):([0-9]+):([^\n]+)\n")
     re_uid = re.compile("UID:([^\n]+)\n")
@@ -48,9 +48,9 @@ META:TS:{1}
 
 
 class Certification(Document):
-    '''
+    """
     A document describing a certification.
-    '''
+    """
 
     re_inline = re.compile("([1-9A-Za-z][^OIl]{42,45}):\
 ([1-9A-Za-z][^OIl]{42,45}):([0-9]+):([A-Za-z0-9+/]+(?:=|==)?)\n")
@@ -58,9 +58,9 @@ class Certification(Document):
 
     def __init__(self, version, currency, pubkey_from, pubkey_to,
                  blocknumber, blockhash, signature):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(version, currency, [signature])
         self.pubkey_from = pubkey_from
         self.pubkey_to = pubkey_to
@@ -85,10 +85,10 @@ class Certification(Document):
 
 
     def sign(self, selfcert, keys):
-        '''
+        """
         Sign the current document.
         Warning : current signatures will be replaced with the new ones.
-        '''
+        """
         self.signatures = []
         for key in keys:
             signing = base64.b64encode(key.signature(bytes(self.raw(selfcert), 'ascii')))
@@ -107,13 +107,13 @@ class Certification(Document):
 
 
 class Revocation(Document):
-    '''
+    """
     A document describing a self-revocation.
-    '''
+    """
     def __init__(self, version, currency, signature):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(version, currency, [signature])
 
     def raw(self, selfcert):
@@ -121,10 +121,10 @@ class Revocation(Document):
 """.format(selfcert.signed_raw())
 
     def sign(self, selfcert, keys):
-        '''
+        """
         Sign the current document.
         Warning : current signatures will be replaced with the new ones.
-        '''
+        """
         self.signatures = []
         for key in keys:
             signing = base64.b64encode(key.signature(bytes(self.raw(selfcert), 'ascii')))
diff --git a/lib/ucoinpy/documents/membership.py b/lib/ucoinpy/documents/membership.py
index af71a3a0e07c381decd50e6207a5513ac63f935a..570110e29772f1ed473f02a5c788cc4505cbe2ca 100644
--- a/lib/ucoinpy/documents/membership.py
+++ b/lib/ucoinpy/documents/membership.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 2 déc. 2014
 
 @author: inso
-'''
+"""
 from .. import PROTOCOL_VERSION
 from . import Document
 
@@ -10,7 +10,7 @@ import re
 
 
 class Membership(Document):
-    '''
+    """
     This is a utility class to generate membership documents :
     Version: VERSION
     Type: Membership
@@ -20,7 +20,7 @@ class Membership(Document):
     Membership: MEMBERSHIP_TYPE
     UserID: USER_ID
     CertTS: CERTIFICATION_TS
-    '''
+    """
 
     # PUBLIC_KEY:SIGNATURE:NUMBER:HASH:TIMESTAMP:USER_ID
     re_inline = re.compile("([1-9A-Za-z][^OIl]{42,45}):([A-Za-z0-9+/]+(?:=|==)?):\
@@ -36,9 +36,9 @@ class Membership(Document):
 
     def __init__(self, version, currency, issuer, block_number, block_hash,
                  membership_type, uid, cert_ts, signature):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(version, currency, [signature])
         self.issuer = issuer
         self.block_number = block_number
diff --git a/lib/ucoinpy/documents/peer.py b/lib/ucoinpy/documents/peer.py
index 6b437a6d3f72f05fcf65292075fac474dc273402..6ca7606c6429b7521318720b0336649676a70dd6 100644
--- a/lib/ucoinpy/documents/peer.py
+++ b/lib/ucoinpy/documents/peer.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 2 déc. 2014
 
 @author: inso
-'''
+"""
 
 import re
 
diff --git a/lib/ucoinpy/documents/status.py b/lib/ucoinpy/documents/status.py
index 2ba47ea89c585d9af302c7272a68943f103b0460..f11e7542c338f57831f6972f11a260a10d0d0254 100644
--- a/lib/ucoinpy/documents/status.py
+++ b/lib/ucoinpy/documents/status.py
@@ -1,15 +1,15 @@
-'''
+"""
 Created on 2 déc. 2014
 
 @author: inso
-'''
+"""
 
 import re
 from . import Document
 
 
 class Status(Document):
-    '''
+    """
     Version: VERSION
     Type: Status
     Currency: CURRENCY_NAME
@@ -17,7 +17,7 @@ class Status(Document):
     Block: BLOCK
     From: SENDER
     To: RECIPIENT
-    '''
+    """
 
     re_type = re.compile("Type: (Status)")
     re_status = re.compile("Status: (NEW|NEW_BACK|UP|UP_BACK|DOWN)")
@@ -27,9 +27,9 @@ class Status(Document):
 
     def __init__(self, version, currency, status, blockid, sender,
                  recipient, signature):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(version, currency, [signature])
 
         self.status = status
@@ -70,12 +70,12 @@ class Status(Document):
                    sender, recipient, signature)
 
     def raw(self):
-        return '''Version: {0}
+        return """Version: {0}
 Type: Status
 Currency: {1}
 Status: {2}
 Block: {3}
 From: {4}
 To: {5}
-'''.format(self.version, self.currency, self.status,
+""".format(self.version, self.currency, self.status,
            self.blockid, self.sender, self.recipient)
diff --git a/lib/ucoinpy/documents/transaction.py b/lib/ucoinpy/documents/transaction.py
index e84313f8c27a002eb5e4fd12fb69b7eafe1c9736..0a9d40d21b797cd1dfd7f35bcaac230c73170c6a 100644
--- a/lib/ucoinpy/documents/transaction.py
+++ b/lib/ucoinpy/documents/transaction.py
@@ -1,15 +1,15 @@
-'''
+"""
 Created on 2 déc. 2014
 
 @author: inso
-'''
+"""
 
 from . import Document
 import re
 import logging
 
 class Transaction(Document):
-    '''
+    """
 Document format :
 Version: VERSION
 Type: Transaction
@@ -38,7 +38,7 @@ PUBLIC_KEY:AMOUNT
 COMMENT
 SIGNATURE
 ...
-    '''
+    """
 
     re_type = re.compile("Type: (Transaction)\n")
     re_header = re.compile("TX:([0-9]+):([0-9]+):([0-9]+):([0-9]+):(0|1)\n")
@@ -51,9 +51,9 @@ SIGNATURE
 
     def __init__(self, version, currency, issuers, inputs, outputs,
                  comment, signatures):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(version, currency, signatures)
 
         self.issuers = issuers
@@ -181,9 +181,9 @@ Issuers:
         return doc
 
     def compact(self):
-        '''
+        """
         Return a transaction in its compact format.
-        '''
+        """
         """TX:VERSION:NB_ISSUERS:NB_INPUTS:NB_OUTPUTS:HAS_COMMENT
 PUBLIC_KEY:INDEX
 ...
@@ -213,26 +213,26 @@ COMMENT
 
 
 class SimpleTransaction(Transaction):
-    '''
+    """
 As transaction class, but for only one issuer.
 ...
-    '''
+    """
     def __init__(self, version, currency, issuer,
                  single_input, outputs, comment, signature):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(version, currency, [issuer], [single_input],
               outputs, comment, [signature])
 
 
 class InputSource():
-    '''
+    """
     A Transaction INPUT
 
     Compact :
     INDEX:SOURCE:FINGERPRINT:AMOUNT
-    '''
+    """
     re_inline = re.compile("([0-9]+):(D|T):([0-9]+):\
 ([0-9a-fA-F]{5,40}):([0-9]+)\n")
     re_compact = re.compile("([0-9]+):(D|T):([0-9a-fA-F]{5,40}):([0-9]+)\n")
@@ -278,9 +278,9 @@ class InputSource():
 
 
 class OutputSource():
-    '''
+    """
     A Transaction OUTPUT
-    '''
+    """
     re_inline = re.compile("([1-9A-Za-z][^OIl]{42,45}):([0-9]+)")
 
     def __init__(self, pubkey, amount):
diff --git a/lib/ucoinpy/key/__init__.py b/lib/ucoinpy/key/__init__.py
index 191bf3786c47f93b4fa9daaf4f10f58874063482..f0813ef87b1962e027593dd312548c61d78c2f5d 100644
--- a/lib/ucoinpy/key/__init__.py
+++ b/lib/ucoinpy/key/__init__.py
@@ -1,8 +1,8 @@
-'''
+"""
 Ucoin public and private keys
 
 @author: inso
-'''
+"""
 
 import base58
 import base64
diff --git a/lib/ucoinpy/key/hdwallet.py b/lib/ucoinpy/key/hdwallet.py
index dffb5fffa8515b8d8433e9af2b965bf16ae3b459..1a135d7da916fb4155d1fb8116859ec753d2e91d 100644
--- a/lib/ucoinpy/key/hdwallet.py
+++ b/lib/ucoinpy/key/hdwallet.py
@@ -1,9 +1,9 @@
-'''
+"""
 HD Wallet inspired from Bip32 wallets.
 
 @author: inso
-'''
-'''
+"""
+"""
 import os
 import hmac
 import hashlib
@@ -375,4 +375,4 @@ if __name__ == "__main__":
     print "* [Chain m/0/2147483647h/1/2147483646h/2]"
     m = m.ChildKey(2)
     m.dump()
-'''
\ No newline at end of file
+"""
\ No newline at end of file
diff --git a/src/cutecoin/core/account.py b/src/cutecoin/core/account.py
index c14a42751ce454f1debba8c6b48d26f28cfc5725..e8b0152d1f9ddbd15e24b77becd66dd242f54e1f 100644
--- a/src/cutecoin/core/account.py
+++ b/src/cutecoin/core/account.py
@@ -130,7 +130,7 @@ class Account(QObject):
     broadcast_error = pyqtSignal(int, str)
 
     def __init__(self, salt, pubkey, name, communities, wallets, contacts, identities_registry):
-        '''
+        """
         Create an account
 
         :param str salt: The root key salt
@@ -144,7 +144,7 @@ class Account(QObject):
         :param cutecoin.core.registry.IdentitiesRegistry: The identities registry intance
 
         .. warnings:: The class methods create and load should be used to create an account
-        '''
+        """
         super().__init__()
         self.salt = salt
         self.pubkey = pubkey
@@ -158,7 +158,7 @@ class Account(QObject):
 
     @classmethod
     def create(cls, name, identities_registry):
-        '''
+        """
         Factory method to create an empty account object
         This new account doesn't have any key and it should be given
         one later
@@ -168,20 +168,20 @@ class Account(QObject):
 
         :param str name: The account name, same as network identity uid
         :return: A new empty account object
-        '''
+        """
         account = cls(None, None, name, [], [], [], identities_registry)
         return account
 
     @classmethod
     def load(cls, json_data, network_manager, identities_registry):
-        '''
+        """
         Factory method to create an Account object from its json view.
         :rtype : cutecoin.core.account.Account
         :param dict json_data: The account view as a json dict
         :param PyQt5.QtNetwork import QNetworkManager: network_manager
         :param cutecoin.core.registry.self._identities_registry: identities_registry
         :return: A new account object created from the json datas
-        '''
+        """
         salt = json_data['salt']
         pubkey = json_data['pubkey']
 
@@ -205,22 +205,22 @@ class Account(QObject):
         return account
 
     def __eq__(self, other):
-        '''
+        """
         :return: True if account.pubkey == other.pubkey
-        '''
+        """
         if other is not None:
             return other.pubkey == self.pubkey
         else:
             return False
 
     def check_password(self, password):
-        '''
+        """
         Method to verify the key password validity
 
         :param str password: The key password
         :return: True if the generated pubkey is the same as the account
         .. warnings:: Generates a new temporary SigningKey
-        '''
+        """
         key = SigningKey(self.salt, password)
         return (key.pubkey == self.pubkey)
 
@@ -233,11 +233,11 @@ class Account(QObject):
         self.contacts.append(new_contact)
 
     def add_community(self, community):
-        '''
+        """
         Add a community to the account
 
         :param community: A community object to add
-        '''
+        """
         self.communities.append(community)
         return community
 
@@ -324,12 +324,12 @@ class Account(QObject):
         return Account.referentials[self.referential][5]
 
     def set_walletpool_size(self, size, password):
-        '''
+        """
         Change the size of the wallet pool
 
         :param int size: The new size of the wallet pool
         :param str password: The password of the account, same for all wallets
-        '''
+        """
         logging.debug("Defining wallet pool size")
         if len(self.wallets) < size:
             for i in range(len(self.wallets), size):
@@ -341,13 +341,13 @@ class Account(QObject):
         self.wallets_changed.emit()
 
     def transfers(self, community):
-        '''
+        """
         Get all transfers done in a community by all the wallets
         owned by this account
 
         :param community: The target community of this request
         :return: All account wallets transfers
-        '''
+        """
         sent = []
         for w in self.wallets:
             sent.extend(w.transfers(community))
@@ -355,13 +355,13 @@ class Account(QObject):
 
     @asyncio.coroutine
     def future_amount(self, community):
-        '''
+        """
         Get amount of money owned in a community by all the wallets
         owned by this account
 
         :param community: The target community of this request
         :return: The value of all wallets values accumulated
-        '''
+        """
         value = 0
         for w in self.wallets:
             val = yield from w.future_value(community)
@@ -369,13 +369,13 @@ class Account(QObject):
         return value
 
     def amount(self, community):
-        '''
+        """
         Get amount of money owned in a community by all the wallets
         owned by this account
 
         :param community: The target community of this request
         :return: The value of all wallets values accumulated
-        '''
+        """
         value = 0
         for w in self.wallets:
             val = w.value(community)
@@ -384,12 +384,12 @@ class Account(QObject):
 
     @asyncio.coroutine
     def send_selfcert(self, password, community):
-        '''
+        """
         Send our self certification to a target community
 
         :param str password: The account SigningKey password
         :param community: The community target of the self certification
-        '''
+        """
         selfcert = SelfCertification(PROTOCOL_VERSION,
                                      community.currency,
                                      self.pubkey,
@@ -432,14 +432,14 @@ class Account(QObject):
 
     @asyncio.coroutine
     def send_membership(self, password, community, mstype):
-        '''
+        """
         Send a membership document to a target community.
         Signal "document_broadcasted" is emitted at the end.
 
         :param str password: The account SigningKey password
         :param community: The community target of the membership document
         :param str mstype: The type of membership demand. "IN" to join, "OUT" to leave
-        '''
+        """
         logging.debug("Send membership")
 
         blockid = yield from community.blockid()
@@ -600,11 +600,11 @@ class Account(QObject):
             w.stop_coroutines()
 
     def jsonify(self):
-        '''
+        """
         Get the account in a json format.
 
         :return: A dict view of the account to be saved as json
-        '''
+        """
         data_communities = []
         for c in self.communities:
             data_communities.append(c.jsonify())
diff --git a/src/cutecoin/core/app.py b/src/cutecoin/core/app.py
index d410e53a16fe264e19cad8d52f42159c013ac9f1..75f7961242e97649a5933e46069c8794fae82bce 100644
--- a/src/cutecoin/core/app.py
+++ b/src/cutecoin/core/app.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 1 févr. 2014
 
 @author: inso
-'''
+"""
 
 import os
 import logging
@@ -25,20 +25,20 @@ from ..tools.exceptions import NameAlreadyExists, BadAccountFile
 
 class Application(QObject):
 
-    '''
+    """
     Managing core application datas :
     Accounts list and general configuration
     Saving and loading the application state
-    '''
+    """
 
     version_requested = pyqtSignal()
 
     def __init__(self, argv, qapp, loop):
-        '''
+        """
         Create a new "cutecoin" application
 
         :param argv: The argv parameters of the call
-        '''
+        """
         super().__init__()
         self.accounts = {}
         self.current_account = None
@@ -68,12 +68,12 @@ class Application(QObject):
             logging.debug("Couldn't load translation")
 
     def get_account(self, name):
-        '''
+        """
         Load an account then return it
 
         :param str name: The account name
         :return: The loaded account if it's a success, else return None
-        '''
+        """
         self.load_account(name)
         if name in self.accounts.keys():
             return self.accounts[name]
@@ -81,13 +81,13 @@ class Application(QObject):
             return None
 
     def create_account(self, name):
-        '''
+        """
         Create a new account from its name
 
         :param str name: The account name
         :return: The new account
         :raise: NameAlreadyExists if the account name is already used locally
-        '''
+        """
         for a in self.accounts:
             if a == name:
                 raise NameAlreadyExists(a)
@@ -104,10 +104,10 @@ class Application(QObject):
         self.accounts[account.name] = account
 
     def delete_account(self, account):
-        '''
+        """
         Delete an account.
         Current account changes to None if it is deleted.
-        '''
+        """
         self.accounts.pop(account.name)
         if self.current_account == account:
             self.current_account = None
@@ -158,10 +158,10 @@ class Application(QObject):
             pass
 
     def load_registries(self):
-        '''
+        """
         Load the Person instances of the person module.
         Each instance is unique, and can be find by its public key.
-        '''
+        """
         try:
             identities_path = os.path.join(config.parameters['home'],
                                         '__identities__')
@@ -311,11 +311,11 @@ class Application(QObject):
             json.dump(data, outfile, indent=4, sort_keys=True)
 
     def save_cache(self, account):
-        '''
+        """
         Save the cache of an account
 
         :param account: The account object to save the cache
-        '''
+        """
         if not os.path.exists(os.path.join(config.parameters['home'],
                                         account.name, '__cache__')):
             os.makedirs(os.path.join(config.parameters['home'],
@@ -344,12 +344,12 @@ class Application(QObject):
                 json.dump(data, outfile, indent=4, sort_keys=True)
 
     def import_account(self, file, name):
-        '''
+        """
         Import an account from a tar file and open it
 
         :param str file: The file path of the tar file
         :param str name: The account name
-        '''
+        """
         with tarfile.open(file, "r") as tar:
             path = os.path.join(config.parameters['home'],
                                 name)
@@ -371,12 +371,12 @@ class Application(QObject):
         self.change_current_account(account)
 
     def export_account(self, file, account):
-        '''
+        """
         Export an account to a tar file
 
         :param str file: The filepath of the tar file
         :param account: The account object to export
-        '''
+        """
         with tarfile.open(file, "w") as tar:
             for file in ["properties"]:
                 path = os.path.join(config.parameters['home'],
@@ -384,11 +384,11 @@ class Application(QObject):
                 tar.add(path, file)
 
     def jsonify_accounts(self):
-        '''
+        """
         Jsonify an account
 
         :return: The account as a dict to format as json
-        '''
+        """
         data = []
         logging.debug("{0}".format(self.accounts))
         for account in self.accounts:
@@ -396,11 +396,11 @@ class Application(QObject):
         return data
 
     def jsonify(self):
-        '''
+        """
         Jsonify the app datas
 
         :return: The accounts of the app to format as json
-        '''
+        """
         data = {'local_accounts': self.jsonify_accounts()}
         return data
 
diff --git a/src/cutecoin/core/community.py b/src/cutecoin/core/community.py
index 7a612d09dfeb4bb937e3d7fd224de0bcec6985d1..23409733a5db1285e368547be381fdf099a628f2 100644
--- a/src/cutecoin/core/community.py
+++ b/src/cutecoin/core/community.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 1 févr. 2014
 
 @author: inso
-'''
+"""
 
 import logging
 import hashlib
@@ -207,33 +207,33 @@ class Community(QObject):
         return self.bma_access.get(self, qtbma.blockchain.Parameters)
 
     def certification_expired(self, certtime):
-        '''
+        """
         Return True if the certificaton time is too old
-        '''
+        """
         return time.time() - certtime > self.parameters['sigValidity']
 
     def add_node(self, node):
-        '''
+        """
         Add a peer to the community.
 
         :param peer: The new peer as a ucoinpy Peer object.
-        '''
+        """
         self._network.add_root_node(node)
 
     def remove_node(self, index):
-        '''
+        """
         Remove a node from the community.
 
         :param index: The index of the removed node.
-        '''
+        """
         self._network.remove_root_node(index)
 
     def get_block(self, number=None):
-        '''
+        """
         Get a block
 
         :param int number: The block number. If none, returns current block.
-        '''
+        """
         if number is None:
             data = self.bma_access.get(self, qtbma.blockchain.Current)
         else:
@@ -244,11 +244,11 @@ class Community(QObject):
 
     @asyncio.coroutine
     def blockid(self):
-        '''
+        """
         Get the block id.
 
         :return: The current block ID as [NUMBER-HASH] format.
-        '''
+        """
         block = yield from self.bma_access.future_request(qtbma.blockchain.Current)
         signed_raw = "{0}{1}\n".format(block['raw'], block['signature'])
         block_hash = hashlib.sha1(signed_raw.encode("ascii")).hexdigest().upper()
@@ -256,11 +256,11 @@ class Community(QObject):
         return {'number': block_number, 'hash': block_hash}
 
     def members_pubkeys(self):
-        '''
+        """
         Listing members pubkeys of a community
 
         :return: All members pubkeys.
-        '''
+        """
         memberships = self.bma_access.get(self, qtbma.wot.Members)
         return [m['pubkey'] for m in memberships["results"]]
 
@@ -268,11 +268,11 @@ class Community(QObject):
         self.network.stop_coroutines()
 
     def jsonify(self):
-        '''
+        """
         Jsonify the community datas.
 
         :return: The community as a dict in json format.
-        '''
+        """
 
         nodes_data = []
         for node in self._network.root_nodes:
diff --git a/src/cutecoin/core/config.py b/src/cutecoin/core/config.py
index 3f35a2550146a95f62a0ac582008859d25aeb341..8a4202d20e3481342de0b88d55335eebc5ff3808 100644
--- a/src/cutecoin/core/config.py
+++ b/src/cutecoin/core/config.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 7 févr. 2014
 
 @author: inso
-'''
+"""
 
 import logging
 from logging import FileHandler
diff --git a/src/cutecoin/core/net/api/bma/access.py b/src/cutecoin/core/net/api/bma/access.py
index 06f2eeb3f8c721947ff8ec07e8217937a8329399..3c6aeffd14365e83e53717652b948001456a56b5 100644
--- a/src/cutecoin/core/net/api/bma/access.py
+++ b/src/cutecoin/core/net/api/bma/access.py
@@ -8,9 +8,9 @@ import asyncio
 import random
 
 class BmaAccess(QObject):
-    '''
+    """
     This class is used to access BMA API.
-    '''
+    """
 
     __saved_requests = [str(blockchain.Block), str(blockchain.Parameters)]
 
@@ -28,13 +28,13 @@ class BmaAccess(QObject):
 
     @classmethod
     def create(cls, network):
-        '''
+        """
         Initialize a new BMAAccess object with empty data.
 
         :param cutecoin.core.net.network.Network network:
         :return: A new BmaAccess object
         :rtype: cutecoin.core.net.api.bma.access.BmaAccess
-        '''
+        """
         return cls({}, network)
 
     @property
@@ -42,11 +42,11 @@ class BmaAccess(QObject):
         return self._data.copy()
 
     def load_from_json(self, json_data):
-        '''
+        """
         Put data in the cache from json datas.
 
         :param dict data: The cache in json format
-        '''
+        """
         data = {}
         for entry in json_data:
             key = entry['key']
@@ -55,11 +55,11 @@ class BmaAccess(QObject):
         self._data = data
 
     def jsonify(self):
-        '''
+        """
         Get the cache in json format
 
         :return: The cache as a dict in json format
-        '''
+        """
         data = {k: self._data[k] for k in self._data.keys()}
         entries = []
         for d in data:
@@ -226,7 +226,7 @@ class BmaAccess(QObject):
                     logging.debug("{0} is not present anymore in pending requests".format(cache_key))
 
     def future_request(self, request, req_args={}, get_args={}):
-        '''
+        """
         Start a request to the network and returns a future.
 
         :param class request: A bma request class calling for data
@@ -234,7 +234,7 @@ class BmaAccess(QObject):
         :param dict get_args: Arguments to pass to the request __get__ method
         :return: The future data
         :rtype: dict
-        '''
+        """
         def handle_future_reply(reply):
             if reply.error() == QNetworkReply.NoError:
                 strdata = bytes(reply.readAll()).decode('utf-8')
@@ -265,14 +265,14 @@ class BmaAccess(QObject):
         return future_data
 
     def simple_request(self, request, req_args={}, get_args={}):
-        '''
+        """
         Start a request to the network but don't cache its result.
 
         :param class request: A bma request class calling for data
         :param dict req_args: Arguments to pass to the request constructor
         :param dict get_args: Arguments to pass to the request __get__ method
         :return: The returned data if cached = True else return the QNetworkReply
-        '''
+        """
         nodes = self._network.synced_nodes
         if len(nodes) > 0:
             node = random.choice(nodes)
@@ -286,7 +286,7 @@ class BmaAccess(QObject):
             raise NoPeerAvailable(self.currency, len(nodes))
 
     def broadcast(self, request, req_args={}, post_args={}):
-        '''
+        """
         Broadcast data to a network.
         Sends the data to all knew nodes.
 
@@ -298,7 +298,7 @@ class BmaAccess(QObject):
 
         .. note:: If one node accept the requests (returns 200),
         the broadcast should be considered accepted by the network.
-        '''
+        """
         nodes = self._network.online_nodes
         replies = []
         for node in nodes:
diff --git a/src/cutecoin/core/net/network.py b/src/cutecoin/core/net/network.py
index 7646ff120cab1f338cee05141407aab53ec1fe1a..f483db38b2bb6a992ec36f7b32196f7ae89e5694 100644
--- a/src/cutecoin/core/net/network.py
+++ b/src/cutecoin/core/net/network.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 24 févr. 2015
 
 @author: inso
-'''
+"""
 from cutecoin.core.net.node import Node
 
 import logging
@@ -14,20 +14,20 @@ from PyQt5.QtCore import pyqtSignal, pyqtSlot, QObject, QCoreApplication, QTimer
 
 
 class Network(QObject):
-    '''
+    """
     A network is managing nodes polling and crawling of a
     given community.
-    '''
+    """
     nodes_changed = pyqtSignal()
     new_block_mined = pyqtSignal(int)
 
     def __init__(self, network_manager, currency, nodes):
-        '''
+        """
         Constructor of a network
 
         :param str currency: The currency name of the community
         :param list nodes: The root nodes of the network
-        '''
+        """
         super().__init__()
         self._root_nodes = nodes
         self._nodes = []
@@ -41,24 +41,24 @@ class Network(QObject):
 
     @classmethod
     def create(cls, network_manager, node):
-        '''
+        """
         Create a new network with one knew node
         Crawls the nodes from the first node to build the
         community network
 
         :param node: The first knew node of the network
-        '''
+        """
         nodes = [node]
         network = cls(network_manager, node.currency, nodes)
         return network
 
     def merge_with_json(self, json_data):
-        '''
+        """
         We merge with knew nodes when we
         last stopped cutecoin
 
         :param dict json_data: Nodes in json format
-        '''
+        """
         for data in json_data:
             node = Node.from_json(self.network_manager, self.currency, data)
             if node.pubkey not in [n.pubkey for n in self.nodes]:
@@ -73,12 +73,12 @@ class Network(QObject):
 
     @classmethod
     def from_json(cls, network_manager, currency, json_data):
-        '''
+        """
         Load a network from a configured community
 
         :param str currency: The currency name of a community
         :param dict json_data: A json_data view of a network
-        '''
+        """
         nodes = []
         for data in json_data:
             node = Node.from_json(network_manager, currency, data)
@@ -87,11 +87,11 @@ class Network(QObject):
         return network
 
     def jsonify(self):
-        '''
+        """
         Get the network in json format.
 
         :return: The network as a dict in json format.
-        '''
+        """
         data = []
         for node in self.nodes:
             data.append(node.jsonify())
@@ -99,18 +99,18 @@ class Network(QObject):
 
     @property
     def quality(self):
-        '''
+        """
         Get a ratio of the synced nodes vs the rest
-        '''
+        """
         synced = len(self.synced_nodes)
         total = len(self.nodes)
         ratio_synced = synced / total
         return ratio_synced
 
     def stop_coroutines(self):
-        '''
+        """
         Stop network nodes crawling.
-        '''
+        """
         self._must_crawl = False
 
     def continue_crawling(self):
@@ -118,80 +118,80 @@ class Network(QObject):
 
     @property
     def synced_nodes(self):
-        '''
+        """
         Get nodes which are in the ONLINE state.
-        '''
+        """
         return [n for n in self.nodes if n.state == Node.ONLINE]
 
     @property
     def online_nodes(self):
-        '''
+        """
         Get nodes which are in the ONLINE state.
-        '''
+        """
         return [n for n in self.nodes if n.state in (Node.ONLINE, Node.DESYNCED)]
 
     @property
     def nodes(self):
-        '''
+        """
         Get all knew nodes.
-        '''
+        """
         return self._nodes
 
     @property
     def root_nodes(self):
-        '''
+        """
         Get root nodes.
-        '''
+        """
         return self._root_nodes
 
     @property
     def latest_block(self):
-        '''
+        """
         Get latest block known
-        '''
+        """
         return max([n.block for n in self.nodes])
 
     def add_node(self, node):
-        '''
+        """
         Add a node to the network.
-        '''
+        """
         self._nodes.append(node)
         node.changed.connect(self.handle_change)
         node.neighbour_found.connect(self.handle_new_node)
         logging.debug("{:} connected".format(node.pubkey[:5]))
 
     def add_root_node(self, node):
-        '''
+        """
         Add a node to the root nodes list
-        '''
+        """
         self._root_nodes.append(node)
 
     def remove_root_node(self, index):
-        '''
+        """
         Remove a node from the root nodes list
-        '''
+        """
         self._root_nodes.pop(index)
 
     def is_root_node(self, node):
-        '''
+        """
         Check if this node is in the root nodes
-        '''
+        """
         return node in self._root_nodes
 
     def root_node_index(self, index):
-        '''
+        """
         Get the index of a root node from its index
         in all nodes list
-        '''
+        """
         node = self.nodes[index]
         return self._root_nodes.index(node)
 
     @asyncio.coroutine
     def discover_network(self):
-        '''
+        """
         Start crawling which never stops.
         To stop this crawling, call "stop_crawling" method.
-        '''
+        """
         self._must_crawl = True
         while self.continue_crawling():
             for node in self.nodes:
diff --git a/src/cutecoin/core/net/node.py b/src/cutecoin/core/net/node.py
index f37776ae03fc9838748afaa4b789a4fd047427a9..ef8bd443286882e96801d53c3b6ffaf79d81d08e 100644
--- a/src/cutecoin/core/net/node.py
+++ b/src/cutecoin/core/net/node.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 21 févr. 2015
 
 @author: inso
-'''
+"""
 
 from ucoinpy.documents.peer import Peer, BMAEndpoint, Endpoint
 from requests.exceptions import RequestException, ConnectionError
@@ -21,14 +21,14 @@ from PyQt5.QtCore import QObject, pyqtSignal, pyqtSlot
 from PyQt5.QtNetwork import QNetworkReply, QNetworkRequest
 
 class Node(QObject):
-    '''
+    """
     A node is a peer seend from the client point of view.
     This node can have multiple states :
     - ONLINE : The node is available for requests
     - OFFLINE: The node is disconnected
     - DESYNCED : The node is online but is desynced from the network
     - CORRUPTED : The node is corrupted, some weird behaviour is going on
-    '''
+    """
 
     ONLINE = 1
     OFFLINE = 2
@@ -40,9 +40,9 @@ class Node(QObject):
 
     def __init__(self, network_manager, currency, endpoints, uid, pubkey, block,
                  state, last_change, last_merkle, software, version):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.network_manager = network_manager
         self._endpoints = endpoints
@@ -59,14 +59,14 @@ class Node(QObject):
 
     @classmethod
     def from_address(cls, network_manager, currency, address, port):
-        '''
+        """
         Factory method to get a node from a given address
 
         :param str currency: The node currency. None if we don't know\
          the currency it should have, for example if its the first one we add
         :param str address: The node address
         :param int port: The node port
-        '''
+        """
         peer_data = qtbma.network.Peering(ConnectionHandler(network_manager, address, port)).get()
 
         peer = Peer.from_signed_raw("{0}{1}\n".format(peer_data['raw'],
@@ -84,13 +84,13 @@ class Node(QObject):
 
     @classmethod
     def from_peer(cls, network_manager, currency, peer):
-        '''
+        """
         Factory method to get a node from a peer document.
 
         :param str currency: The node currency. None if we don't know\
          the currency it should have, for example if its the first one we add
         :param peer: The peer document
-        '''
+        """
         if currency is not None:
             if peer.currency != currency:
                 raise InvalidNodeCurrency(peer.currency, currency)
diff --git a/src/cutecoin/core/registry/identity.py b/src/cutecoin/core/registry/identity.py
index ad26e014a25719491ab1a6a08f9f40bd289cf5f9..23d35a1c509ec6522d204ebf15fe5b7a1e53c3db 100644
--- a/src/cutecoin/core/registry/identity.py
+++ b/src/cutecoin/core/registry/identity.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 11 févr. 2014
 
 @author: inso
-'''
+"""
 
 import logging
 import time
@@ -173,12 +173,12 @@ class Identity(QObject):
         return False
 
     def is_member(self, community):
-        '''
+        """
         Check if the person is a member of a community
 
         :param cutecoin.core.community.Community community: The community target to request the join date
         :return: True if the person is a member of a community
-        '''
+        """
         certifiers = community.bma_access.get(self, qtbma.wot.CertifiersOf, {'search': self.pubkey})
         if certifiers != qtbma.wot.CertifiersOf.null_value:
             return certifiers['isMember']
@@ -241,12 +241,12 @@ class Identity(QObject):
         return unique_valid
 
     def certified_by(self, community):
-        '''
+        """
         Get the list of persons certified by this person
 
         :param cutecoin.core.community.Community community: The community target to request the join date
         :return: The list of the certified persons of this community in BMA json format
-        '''
+        """
         certified_list = community.bma_access.get(self, qtbma.wot.CertifiedBy, {'search': self.pubkey})
         if certified_list == qtbma.wot.CertifiedBy.null_value:
             logging.debug('bma.wot.CertifiersOf request error')
@@ -295,10 +295,10 @@ class Identity(QObject):
         return expiration_date - current_time
 
     def jsonify(self):
-        '''
+        """
         Get the community as dict in json format.
         :return: The community as a dict in json format
-        '''
+        """
         data = {'uid': self.uid,
                 'pubkey': self.pubkey,
                 'status': self.status}
diff --git a/src/cutecoin/core/transfer.py b/src/cutecoin/core/transfer.py
index c7edf796b642f4c3d0141c874de5c94897ac9c43..95b316a6014e56a584801ea7ade6535e954b899e 100644
--- a/src/cutecoin/core/transfer.py
+++ b/src/cutecoin/core/transfer.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 31 janv. 2015
 
 @author: inso
-'''
+"""
 import logging
 import asyncio
 from .net.api import bma as qtbma
@@ -11,7 +11,7 @@ from PyQt5.QtNetwork import QNetworkReply
 import hashlib
 
 class Transfer(QObject):
-    '''
+    """
     A transfer is the lifecycle of a transaction.
     TO_SEND means the transaction wasn't sent yet
     AWAITING means the transaction is waiting for a blockchain validation
@@ -20,7 +20,7 @@ class Transfer(QObject):
     therefore it is considered as refused
     DROPPED means the transaction was canceled locally. It can still be validated
     in the blockchain if it was sent, if the guy is unlucky ;)
-    '''
+    """
     TO_SEND = 0
     AWAITING = 1
     VALIDATED = 2
@@ -31,7 +31,7 @@ class Transfer(QObject):
     broadcast_error = pyqtSignal(int, str)
 
     def __init__(self, hash, state, metadata):
-        '''
+        """
         The constructor of a transfer.
         Check for metadata keys which must be present :
         - receiver
@@ -44,7 +44,7 @@ class Transfer(QObject):
         :param txdoc: The Transaction ucoinpy object
         :param state: The state of the Transfer (TO_SEND, AWAITING, VALIDATED, REFUSED or DROPPED)
         :param metadata: The transfer metadata
-        '''
+        """
         assert('receiver' in metadata)
         assert('block' in metadata)
         assert('time' in metadata)
@@ -62,50 +62,50 @@ class Transfer(QObject):
 
     @classmethod
     def initiate(cls, metadata):
-        '''
+        """
         Create a new transfer in a "TO_SEND" state.
-        '''
+        """
         return cls(None, Transfer.TO_SEND, metadata)
 
     @classmethod
     def create_validated(cls, hash, metadata):
-        '''
+        """
         Create a new transfer in a "VALIDATED" state.
-        '''
+        """
         return cls(hash, Transfer.VALIDATED, metadata)
 
     @classmethod
     def load(cls, data):
-        '''
+        """
         Create a new transfer from a dict in json format.
-        '''
+        """
         return cls(data['hash'], data['state'], data['metadata'])
 
     @property
     def metadata(self):
-        '''
+        """
         :return: this transfer metadata
-        '''
+        """
         return self._metadata
 
     def jsonify(self):
-        '''
+        """
         :return: The transfer as a dict in json format
-        '''
+        """
         return {'hash': self.hash,
                 'state': self.state,
                 'metadata': self._metadata}
 
     @asyncio.coroutine
     def send(self, txdoc, community):
-        '''
+        """
         Send a transaction and update the transfer state to AWAITING if accepted.
         If the transaction was refused (return code != 200), state becomes REFUSED
         The txdoc is saved as the transfer txdoc.
 
         :param txdoc: A transaction ucoinpy object
         :param community: The community target of the transaction
-        '''
+        """
         replies = community.bma_access.broadcast(qtbma.tx.Process,
                     post_args={'transaction': txdoc.signed_raw()})
         for r in replies:
@@ -135,53 +135,53 @@ class Transfer(QObject):
             self.broadcast_error.emit(r.error(), strdata)
 
     def check_registered(self, tx, block, time):
-        '''
+        """
         Check if the transfer was registered in a block.
         Update the transfer state to VALIDATED if it was registered.
 
         :param tx: A transaction ucoinpy object found in the block
         :param int block: The block number checked
         :param int time: The time of the block
-        '''
+        """
         if tx.signed_raw() == self.txdoc.signed_raw():
             self.state = Transfer.VALIDATED
             self._metadata['block'] = block
             self._metadata['time'] = time
 
     def check_refused(self, block):
-        '''
+        """
         Check if the transfer was refused
         If more than 15 blocks were mined since the transaction
         transfer, it is considered as refused.
 
         :param int block: The current block number
-        '''
+        """
         if block > self._metadata['block'] + 15:
             self.state = Transfer.REFUSED
 
     def drop(self):
-        '''
+        """
         Cancel the transfer locally.
         The transfer state becomes "DROPPED".
-        '''
+        """
         self.state = Transfer.DROPPED
 
 
 class Received(Transfer):
     def __init__(self, hash, metadata):
-        '''
+        """
         A transfer were the receiver is the local user.
 
         :param txdoc: The transaction document of the received transfer
         :param metadata: The metadata of the transfer
-        '''
+        """
         super().__init__(hash, Transfer.VALIDATED, metadata)
 
     @classmethod
     def load(cls, data):
-        '''
+        """
         Create a transfer from a dict in json format.
 
         :param data: The transfer as a dict in json format
-        '''
+        """
         return cls(data['hash'], data['metadata'])
diff --git a/src/cutecoin/core/wallet.py b/src/cutecoin/core/wallet.py
index 0d76ee22ad0be423ff42815a64891fc91fc458de..3d996beef8d0d8378ccd1699cca50180fbac6e15 100644
--- a/src/cutecoin/core/wallet.py
+++ b/src/cutecoin/core/wallet.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 1 févr. 2014
 
 @author: inso
-'''
+"""
 
 from ucoinpy.documents.transaction import InputSource, OutputSource, Transaction
 from ucoinpy.key import SigningKey
@@ -21,9 +21,9 @@ import asyncio
 
 
 class Wallet(QObject):
-    '''
+    """
     A wallet is used to manage money with a unique key.
-    '''
+    """
 
     inner_data_changed = pyqtSignal(str)
     refresh_progressed = pyqtSignal(int, int, str)
@@ -32,13 +32,13 @@ class Wallet(QObject):
     broadcast_error = pyqtSignal(int, str)
 
     def __init__(self, walletid, pubkey, name, identities_registry):
-        '''
+        """
         Constructor of a wallet object
 
         :param int walletid: The wallet number, unique between all wallets
         :param str pubkey: The wallet pubkey
         :param str name: The wallet name
-        '''
+        """
         super().__init__()
         self.coins = []
         self.walletid = walletid
@@ -49,14 +49,14 @@ class Wallet(QObject):
 
     @classmethod
     def create(cls, walletid, salt, password, name, identities_registry):
-        '''
+        """
         Factory method to create a new wallet
 
         :param int walletid: The wallet number, unique between all wallets
         :param str salt: The account salt
         :param str password: The account password
         :param str name: The account name
-        '''
+        """
         if walletid == 0:
             key = SigningKey(salt, password)
         else:
@@ -65,66 +65,66 @@ class Wallet(QObject):
 
     @classmethod
     def load(cls, json_data, identities_registry):
-        '''
+        """
         Factory method to load a saved wallet.
 
         :param dict json_data: The wallet as a dict in json format
-        '''
+        """
         walletid = json_data['walletid']
         pubkey = json_data['pubkey']
         name = json_data['name']
         return cls(walletid, pubkey, name, identities_registry)
 
     def load_caches(self, json_data):
-        '''
+        """
         Load this wallet caches.
         Each cache correspond to one different community.
 
         :param dict json_data: The caches as a dict in json format
-        '''
+        """
         for currency in json_data:
             if currency != 'version':
                 self.caches[currency] = TxHistory(self)
                 self.caches[currency].load_from_json(json_data[currency])
 
     def jsonify_caches(self):
-        '''
+        """
         Get this wallet caches as json.
 
         :return: The wallet caches as a dict in json format
-        '''
+        """
         data = {}
         for currency in self.caches:
             data[currency] = self.caches[currency].jsonify()
         return data
 
     def init_cache(self, community):
-        '''
+        """
         Init the cache of this wallet for the specified community.
 
         :param community: The community to refresh its cache
-        '''
+        """
         if community.currency not in self.caches:
             self.caches[community.currency] = TxHistory(self)
 
     def refresh_transactions(self, community, received_list):
-        '''
+        """
         Refresh the cache of this wallet for the specified community.
 
         :param community: The community to refresh its cache
-        '''
+        """
         logging.debug("Refresh transactions for {0}".format(self.pubkey))
         asyncio.async(self.caches[community.currency].refresh(community, received_list))
 
     def check_password(self, salt, password):
-        '''
+        """
         Check if wallet password is ok.
 
         :param salt: The account salt
         :param password: The given password
         :return: True if (salt, password) generates the good public key
         .. warning:: Generates a new temporary SigningKey from salt and password
-        '''
+        """
         key = None
         if self.walletid == 0:
             key = SigningKey(salt, password)
@@ -133,12 +133,12 @@ class Wallet(QObject):
         return (key.pubkey == self.pubkey)
 
     def relative_value(self, community):
-        '''
+        """
         Get wallet value relative to last generated UD
 
         :param community: The community to get value
         :return: The wallet relative value
-        '''
+        """
         value = self.value(community)
         ud = community.dividend
         relative_value = value / float(ud)
@@ -146,12 +146,12 @@ class Wallet(QObject):
 
     @asyncio.coroutine
     def future_value(self, community):
-        '''
+        """
         Get wallet absolute value
 
         :param community: The community to get value
         :return: The wallet absolute value
-        '''
+        """
         value = 0
         sources = yield from self.future_sources(community)
         for s in sources:
@@ -159,12 +159,12 @@ class Wallet(QObject):
         return value
 
     def value(self, community):
-        '''
+        """
         Get wallet absolute value
 
         :param community: The community to get value
         :return: The wallet absolute value
-        '''
+        """
         value = 0
         sources = self.sources(community)
         for s in sources:
@@ -172,14 +172,14 @@ class Wallet(QObject):
         return value
 
     def tx_inputs(self, amount, community):
-        '''
+        """
         Get inputs to generate a transaction with a given amount of money
 
         :param int amount: The amount target value
         :param community: The community target of the transaction
 
         :return: The list of inputs to use in the transaction document
-        '''
+        """
         value = 0
         inputs = []
         cache = self.caches[community.currency]
@@ -198,7 +198,7 @@ class Wallet(QObject):
                                   len(inputs), amount)
 
     def tx_outputs(self, pubkey, amount, inputs):
-        '''
+        """
         Get outputs to generate a transaction with a given amount of money
 
         :param str pubkey: The target pubkey of the transaction
@@ -206,7 +206,7 @@ class Wallet(QObject):
         :param list inputs: The inputs used to send the given amount of money
 
         :return: The list of outputs to use in the transaction document
-        '''
+        """
         outputs = []
         inputs_value = 0
         for i in inputs:
@@ -222,7 +222,7 @@ class Wallet(QObject):
     @asyncio.coroutine
     def send_money(self, salt, password, community,
                    recipient, amount, message):
-        '''
+        """
         Send money to a given recipient in a specified community
 
         :param str salt: The account salt
@@ -231,7 +231,7 @@ class Wallet(QObject):
         :param str recipient: The pubkey of the recipient
         :param int amount: The amount of money to transfer
         :param str message: The message to send with the transfer
-        '''
+        """
         blockid = yield from community.blockid()
         block_number = blockid['number']
         block = yield from community.bma_access.future_request(qtbma.blockchain.Block,
@@ -292,12 +292,12 @@ class Wallet(QObject):
 
     @asyncio.coroutine
     def future_sources(self, community):
-        '''
+        """
         Get available sources in a given community
 
         :param cutecoin.core.community.Community community: The community where we want available sources
         :return: List of InputSource ucoinpy objects
-        '''
+        """
         data = yield from community.bma_access.future_request(qtbma.tx.Sources,
                                  req_args={'pubkey': self.pubkey})
         tx = []
@@ -306,12 +306,12 @@ class Wallet(QObject):
         return tx
 
     def sources(self, community):
-        '''
+        """
         Get available sources in a given community
 
         :param cutecoin.core.community.Community community: The community where we want available sources
         :return: List of InputSource ucoinpy objects
-        '''
+        """
         data = community.bma_access.get(self, qtbma.tx.Sources,
                                  req_args={'pubkey': self.pubkey})
         tx = []
@@ -320,12 +320,12 @@ class Wallet(QObject):
         return tx
 
     def transfers(self, community):
-        '''
+        """
         Get all transfers objects of this wallet
 
         :param community: The community we want to get the executed transfers
         :return: A list of Transfer objects
-        '''
+        """
         if community.currency in self.caches:
             return self.caches[community.currency].transfers
         else:
@@ -336,11 +336,11 @@ class Wallet(QObject):
             c.stop_coroutines()
 
     def jsonify(self):
-        '''
+        """
         Get the wallet as json format.
 
         :return: The wallet as a dict in json format.
-        '''
+        """
         return {'walletid': self.walletid,
                 'pubkey': self.pubkey,
                 'name': self.name}
diff --git a/src/cutecoin/gen_resources/__init__.py b/src/cutecoin/gen_resources/__init__.py
index 82d70b56cad15bed8a6accdacfde0024af7e40a8..260b8d64fc04e27477f54b75e0ced47834eb159f 100644
--- a/src/cutecoin/gen_resources/__init__.py
+++ b/src/cutecoin/gen_resources/__init__.py
@@ -1,5 +1,5 @@
-'''
+"""
 Created on 11 mars 2014
 
 @author: inso
-'''
+"""
diff --git a/src/cutecoin/gui/__init__.py b/src/cutecoin/gui/__init__.py
index 19560381f7b99b47389d0bd8d6fddad655d596eb..3d5bba2e32c7b314ba23fc09e9d0566c0319d4c8 100644
--- a/src/cutecoin/gui/__init__.py
+++ b/src/cutecoin/gui/__init__.py
@@ -1,6 +1,6 @@
-'''
+"""
 Created on 11 mars 2014
 
 @author: inso
-'''
+"""
 from PyQt5 import QtSvg
\ No newline at end of file
diff --git a/src/cutecoin/gui/certification.py b/src/cutecoin/gui/certification.py
index 9de66b8fd2d86333b2a9feb339b39c801dd77b6b..25f860710127a02bf4cc545a0fcf874d251efae9 100644
--- a/src/cutecoin/gui/certification.py
+++ b/src/cutecoin/gui/certification.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 24 dec. 2014
 
 @author: inso
-'''
+"""
 from PyQt5.QtWidgets import QDialog, QMessageBox, QDialogButtonBox, QApplication
 from PyQt5.QtCore import Qt, pyqtSlot
 import quamash
@@ -13,14 +13,14 @@ import asyncio
 
 class CertificationDialog(QDialog, Ui_CertificationDialog):
 
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, certifier, app, password_asker):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.setupUi(self)
         self.app = app
diff --git a/src/cutecoin/gui/community_tab.py b/src/cutecoin/gui/community_tab.py
index 38f7cdd81a358dffd8cd311a373150fb695e2951..1096583e991852deecf572c9bccabdcc47afb8cd 100644
--- a/src/cutecoin/gui/community_tab.py
+++ b/src/cutecoin/gui/community_tab.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 2 févr. 2014
 
 @author: inso
-'''
+"""
 
 import logging
 from PyQt5.QtCore import Qt, pyqtSlot
@@ -24,9 +24,9 @@ from ..core.net.api import bma as qtbma
 
 class CommunityTabWidget(QWidget, Ui_CommunityTabWidget):
 
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, app, account, community, password_asker, parent):
         """
@@ -325,10 +325,10 @@ Revoking your UID can only success if it is not already validated by the network
         self.refresh(identities)
 
     def refresh(self, identities):
-        '''
+        """
         Refresh the table with specified identities.
         If no identities is passed, use the account connections.
-        '''
+        """
         self.table_identities.model().sourceModel().refresh_identities(identities)
         self.table_identities.resizeColumnsToContents()
 
diff --git a/src/cutecoin/gui/contact.py b/src/cutecoin/gui/contact.py
index 59e2f0042f4c7a8341caf5123a32c78d604d3ce4..8e26de9708940be7b1212853d6e42f004d327564 100644
--- a/src/cutecoin/gui/contact.py
+++ b/src/cutecoin/gui/contact.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 2 févr. 2014
 
 @author: inso
-'''
+"""
 import re
 import logging
 
@@ -14,14 +14,14 @@ from ..gen_resources.contact_uic import Ui_ConfigureContactDialog
 
 class ConfigureContactDialog(QDialog, Ui_ConfigureContactDialog):
 
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, account, parent=None, contact=None, index_edit=None):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.setupUi(self)
         self.account = account
diff --git a/src/cutecoin/gui/currency_tab.py b/src/cutecoin/gui/currency_tab.py
index 603d3e027c886147d99efc07b3f254e58b823db2..2c687842bc6d461c30bd2756f646960184f7c323 100644
--- a/src/cutecoin/gui/currency_tab.py
+++ b/src/cutecoin/gui/currency_tab.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 2 févr. 2014
 
 @author: inso
-'''
+"""
 
 import time
 import logging
@@ -24,14 +24,14 @@ from ..core.registry import IdentitiesRegistry
 
 class CurrencyTabWidget(QWidget, Ui_CurrencyTabWidget):
 
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, app, community, password_asker, status_label):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.setupUi(self)
         self.app = app
@@ -121,10 +121,10 @@ class CurrencyTabWidget(QWidget, Ui_CurrencyTabWidget):
 
     @pyqtSlot(int)
     def refresh_block(self, block_number):
-        '''
+        """
         When a new block is found, start handling data.
         @param: block_number: The number of the block mined
-        '''
+        """
         logging.debug("Refresh block")
         self.status_info.clear()
         try:
@@ -156,9 +156,9 @@ class CurrencyTabWidget(QWidget, Ui_CurrencyTabWidget):
         self.refresh_data()
 
     def refresh_data(self):
-        '''
+        """
         Refresh data when the blockchain watcher finished handling datas
-        '''
+        """
         if self.tab_wallets:
             self.tab_wallets.refresh()
 
@@ -167,9 +167,9 @@ class CurrencyTabWidget(QWidget, Ui_CurrencyTabWidget):
 
     @pyqtSlot()
     def refresh_status(self):
-        '''
+        """
         Refresh status bar
-        '''
+        """
         logging.debug("Refresh status")
         text = self.tr(" Block {0}").format(self.community.network.latest_block)
         if self.community.network.quality > 0.66:
diff --git a/src/cutecoin/gui/import_account.py b/src/cutecoin/gui/import_account.py
index dae6192c02afc00e3fddef31ab2e000ebedf5be4..bd3c0a52eea9d20f6fe0e5edb6059bf58a8713de 100644
--- a/src/cutecoin/gui/import_account.py
+++ b/src/cutecoin/gui/import_account.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 22 mai 2014
 
 @author: inso
-'''
+"""
 import re
 from PyQt5.QtWidgets import QDialog, QDialogButtonBox, QMessageBox, QFileDialog
 
@@ -12,14 +12,14 @@ from cutecoin.gen_resources.import_account_uic import Ui_ImportAccountDialog
 
 class ImportAccountDialog(QDialog, Ui_ImportAccountDialog):
 
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, app, parent=None):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.setupUi(self)
         self.app = app
diff --git a/src/cutecoin/gui/mainwindow.py b/src/cutecoin/gui/mainwindow.py
index 8cb5815e537a2f32d763de607a36f78c0a15bfbc..8caaeb1b35d9b2fbaa58edbbfcf009b8603e716d 100644
--- a/src/cutecoin/gui/mainwindow.py
+++ b/src/cutecoin/gui/mainwindow.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 1 févr. 2014
 
 @author: inso
-'''
+"""
 from ..gen_resources.mainwindow_uic import Ui_MainWindow
 from ..gen_resources.about_uic import Ui_AboutPopup
 
@@ -29,9 +29,9 @@ import logging
 
 
 class MainWindow(QMainWindow, Ui_MainWindow):
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, app):
         """
@@ -296,11 +296,11 @@ class MainWindow(QMainWindow, Ui_MainWindow):
                 delete_action.triggered.connect(self.delete_contact)
 
     def refresh(self):
-        '''
+        """
         Refresh main window
         When the selected account changes, all the widgets
         in the window have to be refreshed
-        '''
+        """
         logging.debug("Refresh started")
         self.refresh_accounts()
 
diff --git a/src/cutecoin/gui/network_tab.py b/src/cutecoin/gui/network_tab.py
index bd97eda945c8d2e48e7f0d1c6fa2f923870b7237..1816942cc45a17b3c4b64616cdb860c3f1dd25bd 100644
--- a/src/cutecoin/gui/network_tab.py
+++ b/src/cutecoin/gui/network_tab.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 20 févr. 2015
 
 @author: inso
-'''
+"""
 
 import logging
 from PyQt5.QtGui import QCursor
@@ -13,14 +13,14 @@ from ..gen_resources.network_tab_uic import Ui_NetworkTabWidget
 
 
 class NetworkTabWidget(QWidget, Ui_NetworkTabWidget):
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, community):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.setupUi(self)
         model = NetworkTableModel(community)
diff --git a/src/cutecoin/gui/password_asker.py b/src/cutecoin/gui/password_asker.py
index 2009f8720f92613fed576275609968eddfba08b6..dcb65ddd1851dab1c0ae2cd21365f3a06a2979a8 100644
--- a/src/cutecoin/gui/password_asker.py
+++ b/src/cutecoin/gui/password_asker.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 24 dec. 2014
 
 @author: inso
-'''
+"""
 
 import logging
 import re
@@ -14,14 +14,14 @@ from ..gen_resources.password_asker_uic import Ui_PasswordAskerDialog
 
 class PasswordAskerDialog(QDialog, Ui_PasswordAskerDialog):
 
-    '''
+    """
     A dialog to get password.
-    '''
+    """
 
     def __init__(self, account):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.setupUi(self)
         self.account = account
diff --git a/src/cutecoin/gui/preferences.py b/src/cutecoin/gui/preferences.py
index 91f0026efef99365da97c6b115bc59a7aea559c1..c674625c1a8fe27d58cfe6f39e4dfdb9a874dc36 100644
--- a/src/cutecoin/gui/preferences.py
+++ b/src/cutecoin/gui/preferences.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 11 mai 2015
 
 @author: inso
-'''
+"""
 
 from PyQt5.QtCore import QCoreApplication
 
@@ -15,14 +15,14 @@ from ..gen_resources.preferences_uic import Ui_PreferencesDialog
 
 class PreferencesDialog(QDialog, Ui_PreferencesDialog):
 
-    '''
+    """
     A dialog to get password.
-    '''
+    """
 
     def __init__(self, app):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.setupUi(self)
         self.app = app
diff --git a/src/cutecoin/gui/process_cfg_account.py b/src/cutecoin/gui/process_cfg_account.py
index 50b1bc7271b5708a95131ee8a63d779084cf9212..a13516f607710098b66ddb82d1f0e451b8b20794 100644
--- a/src/cutecoin/gui/process_cfg_account.py
+++ b/src/cutecoin/gui/process_cfg_account.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 6 mars 2014
 
 @author: inso
-'''
+"""
 import logging
 import requests
 from ucoinpy.documents.peer import Peer
@@ -24,9 +24,9 @@ class Step():
 
 
 class StepPageInit(Step):
-    '''
+    """
     First step when adding a community
-    '''
+    """
 
     def __init__(self, config_dialog):
         super().__init__(config_dialog)
@@ -59,9 +59,9 @@ class StepPageInit(Step):
 
 
 class StepPageKey(Step):
-    '''
+    """
     First step when adding a community
-    '''
+    """
 
     def __init__(self, config_dialog):
         super().__init__(config_dialog)
@@ -107,9 +107,9 @@ class StepPageKey(Step):
 
 
 class StepPageCommunities(Step):
-    '''
+    """
     First step when adding a community
-    '''
+    """
 
     def __init__(self, config_dialog):
         super().__init__(config_dialog)
@@ -140,14 +140,14 @@ class StepPageCommunities(Step):
 
 
 class ProcessConfigureAccount(QDialog, Ui_AccountConfigurationDialog):
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, app, account):
-        '''
+        """
         Constructor
-        '''
+        """
         # Set up the user interface from Designer.
         super().__init__()
         self.setupUi(self)
diff --git a/src/cutecoin/gui/process_cfg_community.py b/src/cutecoin/gui/process_cfg_community.py
index eb6d49ac2bb429b263093321be6cb23dd25ee6f8..05e16fdc3b9fa7e9dd5107476ebf7b32e95234c9 100644
--- a/src/cutecoin/gui/process_cfg_community.py
+++ b/src/cutecoin/gui/process_cfg_community.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 8 mars 2014
 
 @author: inso
-'''
+"""
 
 import logging
 import requests
@@ -25,9 +25,9 @@ class Step():
 
 
 class StepPageInit(Step):
-    '''
+    """
     First step when adding a community
-    '''
+    """
     def __init__(self, config_dialog):
         super().__init__(config_dialog)
         self.node = None
@@ -47,9 +47,9 @@ class StepPageInit(Step):
         return True
 
     def process_next(self):
-        '''
+        """
         We create the community
-        '''
+        """
         account = self.config_dialog.account
         logging.debug("Account : {0}".format(account))
         self.config_dialog.community = Community.create(self.node)
@@ -59,9 +59,9 @@ class StepPageInit(Step):
 
 
 class StepPageAddpeers(Step):
-    '''
+    """
     The step where the user add peers
-    '''
+    """
     def __init__(self, config_dialog):
         super().__init__(config_dialog)
 
@@ -85,14 +85,14 @@ class StepPageAddpeers(Step):
 
 
 class ProcessConfigureCommunity(QDialog, Ui_CommunityConfigurationDialog):
-    '''
+    """
     Dialog to configure or add a community
-    '''
+    """
 
     def __init__(self, account, community, password_asker, default_node=None):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.setupUi(self)
         self.community = community
@@ -143,9 +143,9 @@ class ProcessConfigureCommunity(QDialog, Ui_CommunityConfigurationDialog):
             self.step.display_page()
 
     def add_node(self):
-        '''
+        """
         Add node slot
-        '''
+        """
         server = self.lineedit_add_address.text()
         port = self.spinbox_add_port.value()
 
@@ -158,9 +158,9 @@ class ProcessConfigureCommunity(QDialog, Ui_CommunityConfigurationDialog):
         self.tree_peers.setModel(PeeringTreeModel(self.community))
 
     def remove_node(self):
-        '''
+        """
         Remove node slot
-        '''
+        """
         logging.debug("Remove node")
         index = self.sender().data()
         self.community.remove_node(index)
@@ -188,7 +188,7 @@ class ProcessConfigureCommunity(QDialog, Ui_CommunityConfigurationDialog):
 
     def accept(self):
         try:
-            Person.lookup(self.account.pubkey, self.community, cached=False)
+            yield from Person.lookup(self.account.pubkey, self.community, cached=False)
         except LookupFailureError as e:
             reply = QMessageBox.question(self, self.tr("Pubkey not found"),
                                  self.tr("""The public key of your account wasn't found in the community. :\n
diff --git a/src/cutecoin/gui/toast.py b/src/cutecoin/gui/toast.py
index 52fddab8a7e2cc0d868553a1bfe281c21e55095f..a259e9e9acbe78a7163f379bbd6d23925caf42c5 100644
--- a/src/cutecoin/gui/toast.py
+++ b/src/cutecoin/gui/toast.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 1 mai 2015
 
 @author: inso
-'''
+"""
 import sys, time
 import logging
 from PyQt5.QtCore import Qt, QThread
diff --git a/src/cutecoin/gui/transfer.py b/src/cutecoin/gui/transfer.py
index 9fe89882ed519c95e3fb16d6fa20007a614dcf82..b62f1e7acc0764a6330f875515816704b7abfab1 100644
--- a/src/cutecoin/gui/transfer.py
+++ b/src/cutecoin/gui/transfer.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 2 févr. 2014
 
 @author: inso
-'''
+"""
 from PyQt5.QtWidgets import QDialog, QMessageBox, QApplication
 from PyQt5.QtCore import QRegExp, Qt, QLocale, pyqtSlot
 from PyQt5.QtGui import QRegExpValidator
@@ -14,14 +14,14 @@ import asyncio
 
 class TransferMoneyDialog(QDialog, Ui_TransferMoneyDialog):
 
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, sender, password_asker):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__()
         self.setupUi(self)
         self.account = sender
diff --git a/src/cutecoin/gui/wallets_tab.py b/src/cutecoin/gui/wallets_tab.py
index cb39c8f937cdba08a203dbffa90478d2618061e8..b386a743e435da984f48e5f3b35dafdf5455366b 100644
--- a/src/cutecoin/gui/wallets_tab.py
+++ b/src/cutecoin/gui/wallets_tab.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 15 févr. 2015
 
 @author: inso
-'''
+"""
 
 import logging
 from PyQt5.QtWidgets import QWidget, QMenu, QAction, QApplication, QDialog
@@ -18,9 +18,9 @@ from ..gen_resources.wallets_tab_uic import Ui_WalletsTab
 
 
 class WalletsTabWidget(QWidget, Ui_WalletsTab):
-    '''
+    """
     classdocs
-    '''
+    """
 
     def __init__(self, app, account, community, password_asker):
         """
diff --git a/src/cutecoin/models/communities.py b/src/cutecoin/models/communities.py
index 2e1479b5de3da5939c4829066f25f8c7ff4ad911..d782ad461a4bcf380af6bbb6dbff24a3f624089d 100644
--- a/src/cutecoin/models/communities.py
+++ b/src/cutecoin/models/communities.py
@@ -1,22 +1,22 @@
-'''
+"""
 Created on 5 févr. 2014
 
 @author: inso
-'''
+"""
 
 from PyQt5.QtCore import QAbstractListModel, Qt
 
 
 class CommunitiesListModel(QAbstractListModel):
 
-    '''
+    """
     A Qt abstract item model to display communities in a tree
-    '''
+    """
 
     def __init__(self, account, parent=None):
-        '''
+        """
         Constructor
-        '''
+        """
         super(CommunitiesListModel, self).__init__(parent)
         self.communities = account.communities
 
diff --git a/src/cutecoin/models/community.py b/src/cutecoin/models/community.py
index 61a239b902c28a67a99101cff5eefdeeb3914094..16babb17f50b415a760af1d68a148f18bcd8ab4d 100644
--- a/src/cutecoin/models/community.py
+++ b/src/cutecoin/models/community.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 5 fevr. 2014
 
 @author: inso
-'''
+"""
 
 
 class CommunityItemModel(object):
diff --git a/src/cutecoin/models/identities.py b/src/cutecoin/models/identities.py
index e30af70dfb8389267fc3110e730d21d1db6e17c6..7e32c77ce057d733d79efe9859aaf0daabd3742f 100644
--- a/src/cutecoin/models/identities.py
+++ b/src/cutecoin/models/identities.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 5 févr. 2014
 
 @author: inso
-'''
+"""
 
 from ..core.net.api import bma as qtbma
 from ..tools.exceptions import NoPeerAvailable, MembershipNotFoundError
@@ -69,14 +69,14 @@ class IdentitiesFilterProxyModel(QSortFilterProxyModel):
 
 class IdentitiesTableModel(QAbstractTableModel):
 
-    '''
+    """
     A Qt abstract item model to display communities in a tree
-    '''
+    """
 
     def __init__(self, community, parent=None):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(parent)
         self.community = community
         self.columns_titles = {
@@ -91,9 +91,9 @@ class IdentitiesTableModel(QAbstractTableModel):
 
     @property
     def pubkeys(self):
-        '''
+        """
         Get pubkeys of displayed identities
-        '''
+        """
         return [i[1] for i in self.identities_data]
 
     def identity_data(self, identity):
diff --git a/src/cutecoin/models/network.py b/src/cutecoin/models/network.py
index 31c801ab12c9be818a69aa0e1bcbeea4d3fc05a3..6056a9feeb6d16b072d8d05e9e25f6cc2aaaefc5 100644
--- a/src/cutecoin/models/network.py
+++ b/src/cutecoin/models/network.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 5 févr. 2014
 
 @author: inso
-'''
+"""
 
 import logging
 
@@ -83,14 +83,14 @@ class NetworkFilterProxyModel(QSortFilterProxyModel):
 
 
 class NetworkTableModel(QAbstractTableModel):
-    '''
+    """
     A Qt abstract item model to display
-    '''
+    """
 
     def __init__(self, community, parent=None):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(parent)
         self.community = community
         self.columns_types = (
diff --git a/src/cutecoin/models/peering.py b/src/cutecoin/models/peering.py
index 307949da2ec871d6cbfc70105420d6d6f45169be..4b2e48c2b4a5a4c2f2041d5eb9836a81751d6b56 100644
--- a/src/cutecoin/models/peering.py
+++ b/src/cutecoin/models/peering.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 5 févr. 2014
 
 @author: inso
-'''
+"""
 
 from PyQt5.QtCore import QAbstractItemModel, QModelIndex, Qt
 import logging
@@ -84,14 +84,14 @@ class NodeItem(object):
 
 class PeeringTreeModel(QAbstractItemModel):
 
-    '''
+    """
     A Qt abstract item model to display nodes of a community
-    '''
+    """
 
     def __init__(self, community):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(None)
         self.nodes = community._network.root_nodes
         self.root_item = RootItem(community.currency)
diff --git a/src/cutecoin/models/txhistory.py b/src/cutecoin/models/txhistory.py
index 328f94a7eb98b952bd0712f035f81c144eba1f41..c34c231ff9639662fd769cf634d8f20f9112e39f 100644
--- a/src/cutecoin/models/txhistory.py
+++ b/src/cutecoin/models/txhistory.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 5 févr. 2014
 
 @author: inso
-'''
+"""
 
 import datetime
 import logging
@@ -150,14 +150,14 @@ class TxFilterProxyModel(QSortFilterProxyModel):
 
 
 class HistoryTableModel(QAbstractTableModel):
-    '''
+    """
     A Qt abstract item model to display communities in a tree
-    '''
+    """
 
     def __init__(self, account, community, parent=None):
-        '''
+        """
         Constructor
-        '''
+        """
         super().__init__(parent)
         self.account = account
         self.community = community
diff --git a/src/cutecoin/models/wallets.py b/src/cutecoin/models/wallets.py
index cb7de68bb83e65ed21704a3f50c5693b8b3549e6..1d4f1cad813aac12e9677b57dfdecec638bd90ff 100644
--- a/src/cutecoin/models/wallets.py
+++ b/src/cutecoin/models/wallets.py
@@ -1,8 +1,8 @@
-'''
+"""
 Created on 8 févr. 2014
 
 @author: inso
-'''
+"""
 import asyncio
 from PyQt5.QtCore import QAbstractTableModel, QSortFilterProxyModel, Qt, QLocale, pyqtSlot
 
@@ -56,9 +56,9 @@ class WalletsFilterProxyModel(QSortFilterProxyModel):
 
 class WalletsTableModel(QAbstractTableModel):
 
-    '''
+    """
     A Qt list model to display wallets and edit their names
-    '''
+    """
 
     def __init__(self, account, community, parent=None):
         """
diff --git a/src/cutecoin/tools/exceptions.py b/src/cutecoin/tools/exceptions.py
index 9f2da1cc73e1cf1d79bb9dd270eb4eb94c0cd8d7..8821d1c8ed90662e22ae4c5f57bc47a6b78581f2 100644
--- a/src/cutecoin/tools/exceptions.py
+++ b/src/cutecoin/tools/exceptions.py
@@ -1,16 +1,16 @@
-'''
+"""
 Created on 9 févr. 2014
 
 @author: inso
-'''
+"""
 
 
 class Error(Exception):
 
     def __init__(self, message):
-        '''
+        """
         Constructor
-        '''
+        """
         self.message = "Error : " + message
 
     def __str__(self):
@@ -19,44 +19,44 @@ class Error(Exception):
 
 class NotMemberOfCommunityError(Error):
 
-    '''
+    """
     Exception raised when adding a community the account is not a member of
-    '''
+    """
 
     def __init__(self, account, community):
-        '''
+        """
         Constructor
-        '''
+        """
         super() \
             .__init__(account + " is not a member of " + community)
 
 
 class LookupFailureError(Error):
 
-    '''
+    """
     Exception raised when looking for a person in a community
     who isnt present in key list
-    '''
+    """
 
     def __init__(self, value, community):
-        '''
+        """
         Constructor
-        '''
+        """
         super() .__init__(
             "Person looked by {0} in {1} not found ".format(value, community))
 
 
 class MembershipNotFoundError(Error):
 
-    '''
+    """
     Exception raised when looking for a person in a community
     who isnt present in key list
-    '''
+    """
 
     def __init__(self, value, community):
-        '''
+        """
         Constructor
-        '''
+        """
         super() .__init__(
             "Membership searched by " +
             value +
@@ -67,29 +67,29 @@ class MembershipNotFoundError(Error):
 
 class AlgorithmNotImplemented(Error):
 
-    '''
+    """
     Exception raised when a coin uses an algorithm not known
-    '''
+    """
 
     def __init__(self, algo_name):
-        '''
+        """
         Constructor
-        '''
+        """
         super() \
             .__init__("Algorithm " + algo_name + " not implemented.")
 
 
 class KeyAlreadyUsed(Error):
 
-    '''
+    """
     Exception raised trying to add an account using
     a key already used for another account.
-    '''
+    """
 
     def __init__(self, new_account, keyid, found_account):
-        '''
+        """
         Constructor
-        '''
+        """
         super() .__init__(
 """Cannot add account {0} :
 the key {1} is already used by {2}""".format(new_account,
@@ -100,15 +100,15 @@ the key {1} is already used by {2}""".format(new_account,
 
 class NameAlreadyExists(Error):
 
-    '''
+    """
     Exception raised trying to add an account using
     a key already used for another account.
-    '''
+    """
 
     def __init__(self, account_name):
-        '''
+        """
         Constructor
-        '''
+        """
         super() .__init__(
             "Cannot add account " +
             account_name +
@@ -117,30 +117,30 @@ class NameAlreadyExists(Error):
 
 class BadAccountFile(Error):
 
-    '''
+    """
     Exception raised trying to add an account using
     a key already used for another account.
-    '''
+    """
 
     def __init__(self, path):
-        '''
+        """
         Constructor
-        '''
+        """
         super() .__init__(
             "File " + path + " is not an account file")
 
 
 class NotEnoughMoneyError(Error):
 
-    '''
+    """
     Exception raised trying to add an account using
     a key already used for another account.
-    '''
+    """
 
     def __init__(self, available, currency, nb_inputs, requested):
-        '''
+        """
         Constructor
-        '''
+        """
         super() .__init__(
             "Only {0} {1} available in {2} sources, needs {3}"
             .format(available,
@@ -150,41 +150,41 @@ class NotEnoughMoneyError(Error):
 
 
 class NoPeerAvailable(Error):
-    '''
+    """
     Exception raised when a community doesn't have any
     peer available.
-    '''
+    """
     def __init__(self, currency, peers):
-        '''
+        """
         Constructor
-        '''
+        """
         super() .__init__(
             "No peer answered in {0} community ({1} peers available)"
             .format(currency, peers))
 
 
 class InvalidNodeCurrency(Error):
-    '''
+    """
     Exception raised when a node doesn't use the intended currency
-    '''
+    """
     def __init__(self, currency, node_currency):
-        '''
+        """
         Constructor
-        '''
+        """
         super() .__init__(
             "Node is working for {0} currency, but should be {1}"
             .format(node_currency, currency))
 
 
 class ContactAlreadyExists(Error):
-    '''
+    """
     Exception raised when a community doesn't have any
     peer available.
-    '''
+    """
     def __init__(self, new_contact, already_contact):
-        '''
+        """
         Constructor
-        '''
+        """
         super() .__init__(
             "Cannot add {0}, he/she has the same pubkey as {1} contact"
             .format(new_contact, already_contact))