Fix quoting in docstring, linting.

accountant/models/accounts.py

@@ -21,7 +21,7 @@ from .operations import Operation
 
 
 class Account(db.Model):
-    "Model class to handle accounts."
+    """Model class to handle accounts."""
     # pylint: disable=invalid-name
     id = db.Column(db.Integer, primary_key=True)
     name = db.Column(db.String(200), nullable=False)
@@ -33,7 +33,7 @@ class Account(db.Model):
 
     @classmethod
     def query(cls, begin=None, end=None):
-        "Return a query for this class method."
+        """Return a query for this class method."""
         return db.session.query(
             cls
         ).order_by(
@@ -41,7 +41,7 @@ class Account(db.Model):
         )
 
     def solds(self):
-        "Return the solds of this account."
+        """Return the solds of this account."""
         # TODO Alexis Lahouze 2017-05-04 Rename to "balances"
         return db.session.query(
             db.func.sum(Operation.value).label("future"),
@@ -64,7 +64,7 @@ class Account(db.Model):
         ).one()
 
     def balance(self, begin, end):
-        "Return the balance for a specific time period."
+        """Return the balance for a specific time period."""
         # TODO Alexis Lahouze 2017-05-04 Rename to "flow" or "cash flow"
         query = db.session.query(
             db.func.sum(
@@ -93,8 +93,9 @@ class Account(db.Model):
         return query.one()
 
     @db.validates('authorized_overdraft')
+    # pylint: disable=no-self-use
     def validate_authorized_overdraft(self, key, authorized_overdraft):
-        "Validator for authorized_overdraft : must be negative."
+        """Validator for authorized_overdraft : must be negative."""
         assert authorized_overdraft <= 0
 
         return authorized_overdraft