diff --git a/accountant/__init__.py b/accountant/__init__.py
index 9964e2d..6b5eefb 100644
--- a/accountant/__init__.py
+++ b/accountant/__init__.py
@@ -14,27 +14,40 @@
     You should have received a copy of the GNU Affero General Public License
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
 """
+from contextlib import contextmanager
 
-from .api import api
-#from api.controller import login_manager
-from .api.model import db
 from flask import Flask
 from flask.ext.sqlalchemy import SQLAlchemy
-from .frontend import frontend
-from sqlalchemy.orm import sessionmaker
+
 from . import config
 
 # The app
-app = Flask(__name__, static_folder = None)
+app = Flask(__name__, static_folder=None)
 
 app.config['SQLALCHEMY_DATABASE_URI'] = config.db_uri
 app.config['SQLALCHEMY_RECORD_QUERIES'] = config.debug
 app.config['WTF_CSRF_ENABLED'] = False
 app.config['SECRET_KEY'] = 'my_secret_key'
 
-db.init_app(app)
-#login_manager.init_app(app)
+db = SQLAlchemy(app)
+
+@contextmanager
+def session_scope():
+    from accountant import db
+    session = db.session
+
+    try:
+        yield session
+        session.commit()
+    except:
+        session.rollback()
+        raise
+    finally:
+        session.close()
+
+# Must be after db declaration because the blueprints may need it.
+from .api import api
+from .frontend import frontend
 
 app.register_blueprint(frontend, url_prefix='')
 app.register_blueprint(api, url_prefix='/api')
-
diff --git a/accountant/api/__init__.py b/accountant/api/__init__.py
index c1bb42d..ddfb551 100644
--- a/accountant/api/__init__.py
+++ b/accountant/api/__init__.py
@@ -1,6 +1,22 @@
+"""
+    This file is part of Accountant.
+
+    Accountant is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Accountant 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 Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
+"""
 from flask import Blueprint
 
 api = Blueprint('api', __name__)
 
+# Load all views.
 from .controller import *
-
diff --git a/accountant/api/controller/__init__.py b/accountant/api/controller/__init__.py
index a27d8eb..44ca585 100644
--- a/accountant/api/controller/__init__.py
+++ b/accountant/api/controller/__init__.py
@@ -1,3 +1,19 @@
+"""
+    This file is part of Accountant.
+
+    Accountant is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Accountant 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 Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
+"""
 import pkgutil
 from flask.ext.httpauth import HTTPBasicAuth
 
@@ -7,6 +23,3 @@ __all__ = []
 
 for loader, module_name, is_pkg in pkgutil.walk_packages(__path__):
     __all__.append(module_name)
-
-from . import *
-
diff --git a/accountant/api/controller/accounts.py b/accountant/api/controller/accounts.py
index c7ce08c..a93602d 100644
--- a/accountant/api/controller/accounts.py
+++ b/accountant/api/controller/accounts.py
@@ -14,15 +14,21 @@
     You should have received a copy of the GNU Affero General Public License
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
 """
+from flask import json, request
+
+from sqlalchemy import func, case, cast, extract, distinct
+
+from forms.accounts import AccountForm
+
+from accountant import db, session_scope
+
 from . import auth
 from .. import api
-from ..model import db, session_scope
+
 from ..model.accounts import Account
 from ..model.entries import Entry
 from ..model.operations import Operation
-from flask import json, request
-from sqlalchemy import func, case, cast, extract, distinct
-from forms.accounts import AccountIdForm, AccountForm
+
 
 @api.route("/accounts", methods=["GET"])
 @auth.login_required
@@ -32,12 +38,14 @@ def get_accounts():
     """
     with session_scope() as session:
         query = session.query(
-          Account.id.label("id"),
-          Account.name.label("name"),
-          Account.authorized_overdraft.label("authorized_overdraft"),
-          func.sum(Entry.value).label("future"),
-          func.sum(case([(Entry.pointed, Entry.value,)], else_=cast(0, db.Numeric(15, 2)))).label("pointed"),
-          func.sum(case([(Entry.operation_date < func.now(), Entry.value,)], else_=cast(0, db.Numeric(15, 2)))).label("current")
+            Account.id.label("id"),
+            Account.name.label("name"),
+            Account.authorized_overdraft.label("authorized_overdraft"),
+            func.sum(Entry.value).label("future"),
+            func.sum(case([(Entry.pointed, Entry.value,)],
+                          else_=cast(0, db.Numeric(15, 2)))).label("pointed"),
+            func.sum(case([(Entry.operation_date < func.now(), Entry.value,)],
+                          else_=cast(0, db.Numeric(15, 2)))).label("current")
         ).outerjoin(Entry).group_by(Account.id).order_by(Account.id)
 
         return json.dumps([{
@@ -49,18 +57,23 @@ def get_accounts():
             "future": str(i.future)
         } for i in query.all()])
 
+
 @api.route("/accounts/<account_id>/<year>/<month>/")
 @auth.login_required
 def get_account_status(account_id, year, month):
     with session_scope() as session:
         query = session.query(
-            func.sum(case([(func.sign(Operation.value) == -1, Operation.value)], else_=0)).label("expenses"),
-            func.sum(case([(func.sign(Operation.value) == 1, Operation.value)], else_=0)).label("revenues"),
+            func.sum(case([(func.sign(Operation.value) == -1, Operation.value)],
+                          else_=0)).label("expenses"),
+            func.sum(case([(func.sign(Operation.value) == 1, Operation.value)],
+                          else_=0)).label("revenues"),
             func.sum(Operation.value).label("balance")
         ).filter(
             Operation.account_id == account_id
         ).filter(
-            func.date_trunc('month', Operation.operation_date) == "%s-%s-01" % (year, month)
+            func.date_trunc('month',
+                            Operation.operation_date) == "%s-%s-01" % (year,
+                                                                       month)
         ).group_by(Operation.account_id)
 
         if query.count() == 1:
@@ -79,13 +92,16 @@ def get_account_status(account_id, year, month):
             "balance": str(balance)
         })
 
+
 @api.route("/accounts/<account_id>/months")
 @auth.login_required
 def get_months(account_id):
     with session_scope() as session:
         query = session.query(
-          distinct(func.lpad(cast(extract("year", Entry.operation_date), db.String), 4, '0')).label("year"),
-          func.lpad(cast(extract("month", Entry.operation_date), db.String), 2, '0').label("month")
+            distinct(func.lpad(cast(extract("year", Entry.operation_date),
+                                    db.String), 4, '0')).label("year"),
+            func.lpad(cast(extract("month", Entry.operation_date),
+                           db.String), 2, '0').label("month")
         ).filter(Entry.account_id == account_id).order_by("year", "month")
 
         return json.dumps([{
@@ -93,11 +109,13 @@ def get_months(account_id):
             "month": i.month.rjust(2, '0')
         } for i in query.all()])
 
+
 @api.route("/accounts", methods=["PUT"])
 @auth.login_required
 def add_account():
     with session_scope() as session:
-        account = Account(request.json['name'], request.json['authorized_overdraft'])
+        account = Account(request.json['name'],
+                          request.json['authorized_overdraft'])
 
         session.add(account)
 
@@ -111,7 +129,10 @@ def update_account(account_id):
 
     if account_form.validate():
         with session_scope() as session:
-            account = session.query(Account).filter(Account.id == account_id).first()
+            query = session.query(Account)
+            query = query.filter(Account.id == account_id)
+
+            account = query.first()
 
             account.name = request.json['name']
             account.authorized_overdraft = request.json['authorized_overdraft']
@@ -120,15 +141,22 @@ def update_account(account_id):
 
             return json.dumps("Account #%s updated." % account_id)
     else:
-        return json.dumps({'ok': False, 'error_type': 'validation', 'errors': account_form.errors})
+        return json.dumps({
+            'ok': False,
+            'error_type': 'validation',
+            'errors': account_form.errorsi
+        })
+
 
 @api.route("/accounts/<account_id>", methods=["DELETE"])
 @auth.login_required
 def delete_account(account_id):
     with session_scope() as session:
-        account = session.query(Account).filter(Account.id == account_id).first()
+        query = session.query(Account)
+        query = query.filter(Account.id == account_id)
+
+        account = query.first()
 
         session.delete(account)
 
         return json.dumps("Account #%s deleted." % account_id)
-
diff --git a/accountant/api/controller/entries.py b/accountant/api/controller/entries.py
index d23cbac..676a36e 100644
--- a/accountant/api/controller/entries.py
+++ b/accountant/api/controller/entries.py
@@ -14,16 +14,17 @@
     You should have received a copy of the GNU Affero General Public License
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
 """
+from flask import json, request
+
+from sqlalchemy import func, case, desc
+
+from accountant import session_scope
+
 from .. import api
-from ..model import db, session_scope
+
 from ..model.entries import Entry
 from ..model.operations import Operation
-from ..model.scheduled_operations import ScheduledOperation
-from flask import json, request
-from sqlalchemy import func, desc
-from sqlalchemy.ext.hybrid import hybrid_property, hybrid_method
-from sqlalchemy.orm import sessionmaker, column_property, aliased
-from sqlalchemy.sql import func, select, case
+
 
 @api.route("/entries/<account_id>/<year>/<month>")
 def get_entries(account_id, year, month):
@@ -33,45 +34,54 @@ def get_entries(account_id, year, month):
     with session_scope() as session:
         base_query = session.query(
             Operation,
-            case(whens={Operation.canceled: None}, else_=func.sum(Operation.value).over(partition_by="canceled", order_by="operation_date, value desc, label desc")).label("sold")
+            case(
+                whens={Operation.canceled: None},
+                else_=func.sum(Operation.value).over(
+                    partition_by="canceled",
+                    order_by="operation_date, value desc, label desc")
+            ).label("sold")
         ).filter(Operation.account_id == account_id).order_by(
             desc(Operation.operation_date),
             Operation.value,
             Operation.label,
         ).subquery()
 
-        query = session.query(base_query).select_from(base_query).filter(func.date_trunc('month', base_query.c.operation_date) == "%s-%s-01" % (year, month))
+        query = session.query(base_query).select_from(base_query)
+        query = query.filter(func.date_trunc(
+            'month', base_query.c.operation_date) == "%s-%s-01" % (year, month))
 
         return json.dumps([{
-             "id": i.id,
-             "pointed": i.pointed,
-             "operation_date": i.operation_date.strftime("%Y-%m-%d"),
-             "label": i.label,
-             "value": str(i.value),
-             "category": i.category,
-             "sold": str(i.sold) if not i.canceled else None,
-             "account_id": i.account_id,
-             "canceled": i.canceled,
-             "scheduled_operation_id": i.scheduled_operation_id
+            "id": i.id,
+            "pointed": i.pointed,
+            "operation_date": i.operation_date.strftime("%Y-%m-%d"),
+            "label": i.label,
+            "value": str(i.value),
+            "category": i.category,
+            "sold": str(i.sold) if not i.canceled else None,
+            "account_id": i.account_id,
+            "canceled": i.canceled,
+            "scheduled_operation_id": i.scheduled_operation_id
         } for i in query.all()])
 
+
 @api.route("/entries", methods=["PUT"])
 def add_entry():
     with session_scope() as session:
         entry = Entry(
-          operation_date = request.json['operation_date'],
-          pointed = request.json['pointed'],
-          label = request.json['label'],
-          value = request.json['value'],
-          category = request.json['category'],
-          account_id = request.json['account_id'],
-          scheduled_operation_id = request.json['scheduled_operation_id']
+            operation_date=request.json['operation_date'],
+            pointed=request.json['pointed'],
+            label=request.json['label'],
+            value=request.json['value'],
+            category=request.json['category'],
+            account_id=request.json['account_id'],
+            scheduled_operation_id=request.json['scheduled_operation_id']
         )
 
         session.add(entry)
 
         return json.dumps("Entry added.")
 
+
 @api.route("/entries/<entry_id>", methods=["PUT"])
 def update_entry(entry_id):
     with session_scope() as session:
@@ -90,6 +100,7 @@ def update_entry(entry_id):
 
         return json.dumps("Entry #%s updated." % entry_id)
 
+
 @api.route("/entries/<entry_id>", methods=["DELETE"])
 def delete_entry(entry_id):
     with session_scope() as session:
@@ -98,4 +109,3 @@ def delete_entry(entry_id):
         session.delete(entry)
 
         return json.dumps("Entry #%s deleted." % entry_id)
-
diff --git a/accountant/api/controller/scheduled_operations.py b/accountant/api/controller/scheduled_operations.py
index f69148e..0df8042 100644
--- a/accountant/api/controller/scheduled_operations.py
+++ b/accountant/api/controller/scheduled_operations.py
@@ -1,11 +1,28 @@
-from .. import api
-from ..model import db, session_scope
-from ..model.scheduled_operations import ScheduledOperation
+"""
+    This file is part of Accountant.
+
+    Accountant is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Accountant 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 Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
+"""
 from flask import json, request
-from sqlalchemy import func, desc
-from sqlalchemy.ext.hybrid import hybrid_property, hybrid_method
-from sqlalchemy.orm import sessionmaker, column_property
-from sqlalchemy.sql import func, select
+
+from sqlalchemy import desc
+
+from accountant import session_scope
+
+from .. import api
+from ..model.scheduled_operations import ScheduledOperation
+
 
 @api.route("/scheduled_operations/<account_id>")
 def get_scheduled_operations(account_id):
@@ -14,51 +31,56 @@ def get_scheduled_operations(account_id):
     """
     with session_scope() as session:
         query = session.query(
-          ScheduledOperation
+            ScheduledOperation
         ).select_from(
-          session.query(ScheduledOperation)
-          .filter(ScheduledOperation.account_id == account_id)
-          .order_by(
-            desc(ScheduledOperation.day),
-            ScheduledOperation.value,
-            ScheduledOperation.label,
-          ).subquery()
+            session.query(ScheduledOperation)
+            .filter(ScheduledOperation.account_id == account_id)
+            .order_by(
+                desc(ScheduledOperation.day),
+                ScheduledOperation.value,
+                ScheduledOperation.label,
+            ).subquery()
         )
 
         return json.dumps([{
-             "id": i.id,
-             "start_date": i.start_date.strftime("%Y-%m-%d"),
-             "stop_date": i.stop_date.strftime("%Y-%m-%d"),
-             "day": str(i.day),
-             "frequency": str(i.frequency),
-             "label": i.label,
-             "value": str(i.value),
-             "category": i.category,
-             "account_id": i.account_id
+            "id": i.id,
+            "start_date": i.start_date.strftime("%Y-%m-%d"),
+            "stop_date": i.stop_date.strftime("%Y-%m-%d"),
+            "day": str(i.day),
+            "frequency": str(i.frequency),
+            "label": i.label,
+            "value": str(i.value),
+            "category": i.category,
+            "account_id": i.account_id
         } for i in query.all()])
 
+
 @api.route("/scheduled_operations", methods=["PUT"])
 def add_scheduled_operation():
     with session_scope() as session:
         scheduledOperation = ScheduledOperation(
-          start_date = request.json['start_date'],
-          stop_date = request.json['stop_date'],
-          day = request.json['day'],
-          frequency = request.json['frequency'],
-          label = request.json['label'],
-          value = request.json['value'],
-          category = request.json['category'],
-          account_id = request.json['account_id']
+            start_date=request.json['start_date'],
+            stop_date=request.json['stop_date'],
+            day=request.json['day'],
+            frequency=request.json['frequency'],
+            label=request.json['label'],
+            value=request.json['value'],
+            category=request.json['category'],
+            account_id=request.json['account_id']
         )
 
         session.add(scheduledOperation)
 
         return json.dumps("Scheduled operation added.")
 
+
 @api.route("/scheduled_operations/<scheduled_operation_id>", methods=["PUT"])
 def update_scheduled_operation(scheduled_operation_id):
     with session_scope() as session:
-        scheduledOperation = session.query(ScheduledOperation).filter(ScheduledOperation.id == scheduled_operation_id).first()
+        query = session.query(ScheduledOperation)
+        query = query.filter(ScheduledOperation.id == scheduled_operation_id)
+
+        scheduledOperation = query.first()
 
         scheduledOperation.id = scheduled_operation_id
         scheduledOperation.start_date = request.json['start_date'],
@@ -72,14 +94,18 @@ def update_scheduled_operation(scheduled_operation_id):
 
         session.merge(scheduledOperation)
 
-        return json.dumps("Scheduled operation #%s updated." % scheduled_operation_id)
+        return json.dumps(
+            "Scheduled operation #%s updated." % scheduled_operation_id)
+
 
 @api.route("/scheduled_operations/<scheduled_operation_id>", methods=["DELETE"])
 def delete_scheduled_operation(scheduled_operation_id):
     with session_scope() as session:
-        scheduledOperation = session.query(ScheduledOperation).filter(ScheduledOperation.id == scheduled_operation_id).first()
+        query = session.query(ScheduledOperation)
+        query = query.filter(ScheduledOperation.id == scheduled_operation_id)
+        scheduledOperation = query.first()
 
         session.delete(scheduledOperation)
 
-        return json.dumps("Scheduled operation #%s deleted." % scheduled_operation_id)
-
+        return json.dumps(
+            "Scheduled operation #%s deleted." % scheduled_operation_id)
diff --git a/accountant/api/controller/users.py b/accountant/api/controller/users.py
index 2abf1c5..9ecf21a 100644
--- a/accountant/api/controller/users.py
+++ b/accountant/api/controller/users.py
@@ -14,10 +14,11 @@
     You should have received a copy of the GNU Affero General Public License
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
 """
+#from accountant import session_scope
 
 from . import auth
-from .. import api
-from ..model import db, session_scope
+#from .. import api
+
 
 @auth.verify_password
 def verify_password(username, password):
diff --git a/accountant/api/model/__init__.py b/accountant/api/model/__init__.py
index 58959f2..96f3e44 100644
--- a/accountant/api/model/__init__.py
+++ b/accountant/api/model/__init__.py
@@ -1,25 +1,19 @@
-from contextlib import contextmanager
-from flask.ext.sqlalchemy import SQLAlchemy
-from sqlalchemy.ext.declarative import declarative_base
-from sqlalchemy.orm import scoped_session, sessionmaker
+"""
+    This file is part of Accountant.
 
-db = SQLAlchemy()
+    Accountant is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
 
-@contextmanager
-def session_scope():
-    #session = scoped_session(sessionmaker(autocommit = False, autoflush = False, bind = engine))
-    session = db.session
-    #Base.query = session.query_property()
-
-    try:
-        yield session
-        session.commit()
-    except:
-        session.rollback()
-        raise
-    finally:
-        session.close()
+    Accountant 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 Affero General Public License for more details.
 
+    You should have received a copy of the GNU Affero General Public License
+    along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
+"""
 import pkgutil
 
 __all__ = []
@@ -27,5 +21,4 @@ __all__ = []
 for loader, module_name, is_pkg in pkgutil.walk_packages(__path__):
     __all__.append(module_name)
 
-from . import *
-
+#from . import *
diff --git a/accountant/api/model/accounts.py b/accountant/api/model/accounts.py
index 1bbbaf1..a8cf396 100644
--- a/accountant/api/model/accounts.py
+++ b/accountant/api/model/accounts.py
@@ -14,14 +14,14 @@
     You should have received a copy of the GNU Affero General Public License
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
 """
-from . import db
+from accountant import db
+
 
 class Account(db.Model):
-    id = db.Column(db.Integer, primary_key = True)
-    name = db.Column(db.String(200), nullable = False)
-    authorized_overdraft = db.Column(db.Integer, nullable = True, default = 0)
+    id = db.Column(db.Integer, primary_key=True)
+    name = db.Column(db.String(200), nullable=False)
+    authorized_overdraft = db.Column(db.Integer, nullable=True, default=0)
 
     def __init__(self, name, authorized_overdraft):
         self.name = name
         self.authorized_overdraft = authorized_overdraft
-
diff --git a/accountant/api/model/entries.py b/accountant/api/model/entries.py
index 225fb39..a59d252 100644
--- a/accountant/api/model/entries.py
+++ b/accountant/api/model/entries.py
@@ -14,28 +14,32 @@
     You should have received a copy of the GNU Affero General Public License
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
 """
-from . import db
+from accountant import db
+
 from .accounts import Account
 from .scheduled_operations import ScheduledOperation
-from sqlalchemy import func, desc
-from sqlalchemy.orm import column_property
-from sqlalchemy.sql import func, select
+
 
 class Entry(db.Model):
     id = db.Column(db.Integer, primary_key=True)
-    pointed = db.Column(db.Boolean, nullable = False, default = False)
-    operation_date = db.Column(db.Date, nullable = False)
-    label = db.Column(db.String(500), nullable = False)
-    value = db.Column(db.Numeric(15, 2), nullable = False)
+    pointed = db.Column(db.Boolean, nullable=False, default=False)
+    operation_date = db.Column(db.Date, nullable=False)
+    label = db.Column(db.String(500), nullable=False)
+    value = db.Column(db.Numeric(15, 2), nullable=False)
     account_id = db.Column(db.Integer, db.ForeignKey('account.id'))
-    scheduled_operation_id = db.Column(db.Integer, db.ForeignKey('scheduled_operation.id'))
+    scheduled_operation_id = db.Column(db.Integer,
+                                       db.ForeignKey('scheduled_operation.id'))
 
-    account = db.relationship(Account, backref = db.backref('entry', lazy="dynamic"))
-    scheduled_operation = db.relationship(ScheduledOperation, backref = db.backref('entry', lazy="dynamic"))
+    account = db.relationship(Account, backref=db.backref('entry',
+                                                          lazy="dynamic"))
+    scheduled_operation = db.relationship(ScheduledOperation,
+                                          backref=db.backref('entry',
+                                                             lazy="dynamic"))
 
-    category = db.Column(db.String(100), nullable = True)
+    category = db.Column(db.String(100), nullable=True)
 
-    def __init__(self, pointed, label, value, account_id, operation_date = None, category = None, scheduled_operation_id = None):
+    def __init__(self, pointed, label, value, account_id, operation_date=None,
+                 category=None, scheduled_operation_id=None):
         self.pointed = pointed
         self.operation_date = operation_date
         self.label = label
@@ -43,4 +47,3 @@ class Entry(db.Model):
         self.account_id = account_id
         self.category = category
         self.scheduled_operation_id = scheduled_operation_id
-
diff --git a/accountant/api/model/operations.py b/accountant/api/model/operations.py
index 42a67aa..4f7d757 100644
--- a/accountant/api/model/operations.py
+++ b/accountant/api/model/operations.py
@@ -14,35 +14,33 @@
     You should have received a copy of the GNU Affero General Public License
     along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
 """
-from . import db
+from accountant import db
 
 from .accounts import Account
-from .scheduled_operations import ScheduledOperation
 
-from sqlalchemy import func, desc
-from sqlalchemy.orm import column_property
-from sqlalchemy.sql import func, select
 
 class Operation(db.Model):
     id = db.Column(db.Integer, primary_key=True)
-    pointed = db.Column(db.Boolean, nullable = False, default = False)
-    operation_date = db.Column(db.Date, nullable = False)
-    label = db.Column(db.String(500), nullable = False)
-    value = db.Column(db.Numeric(15, 2), nullable = False)
+    pointed = db.Column(db.Boolean, nullable=False, default=False)
+    operation_date = db.Column(db.Date, nullable=False)
+    label = db.Column(db.String(500), nullable=False)
+    value = db.Column(db.Numeric(15, 2), nullable=False)
     account_id = db.Column(db.Integer, db.ForeignKey('account.id'))
-    scheduled_operation_id = db.Column(db.Integer, db.ForeignKey('scheduled_operation.id'))
+    scheduled_operation_id = db.Column(db.Integer,
+                                       db.ForeignKey('scheduled_operation.id'))
 
-    account = db.relationship(Account, backref = db.backref('operation', lazy="dynamic"))
+    account = db.relationship(Account, backref=db.backref('operation',
+                                                          lazy="dynamic"))
 
-    category = db.Column(db.String(100), nullable = True)
+    category = db.Column(db.String(100), nullable=True)
 
-    canceled = db.Column(db.Boolean, nullable = False)
+    canceled = db.Column(db.Boolean, nullable=False)
 
-    def __init__(self, pointed, label, value, account_id, operation_date = None, category = None):
+    def __init__(self, pointed, label, value, account_id, operation_date=None,
+                 category=None):
         self.pointed = pointed
         self.operation_date = operation_date
         self.label = label
         self.value = value
         self.account_id = account_id
         self.category = category
-
diff --git a/accountant/api/model/scheduled_operations.py b/accountant/api/model/scheduled_operations.py
index 098ed62..c517821 100644
--- a/accountant/api/model/scheduled_operations.py
+++ b/accountant/api/model/scheduled_operations.py
@@ -1,24 +1,41 @@
-from . import db
+"""
+    This file is part of Accountant.
+
+    Accountant is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Foobar 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 Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with Accountant.  If not, see <http://www.gnu.org/licenses/>.
+"""
+from accountant import db
+
 from .accounts import Account
-from sqlalchemy import func, desc
-from sqlalchemy.orm import column_property
-from sqlalchemy.sql import func, select
+
 
 class ScheduledOperation(db.Model):
     id = db.Column(db.Integer, primary_key=True)
-    start_date = db.Column(db.Date, nullable = False)
-    stop_date = db.Column(db.Date, nullable = False)
-    day = db.Column(db.Integer, nullable = False)
-    frequency = db.Column(db.Integer, nullable = False)
-    label = db.Column(db.String(500), nullable = False)
-    value = db.Column(db.Numeric(15, 2), nullable = False)
+    start_date = db.Column(db.Date, nullable=False)
+    stop_date = db.Column(db.Date, nullable=False)
+    day = db.Column(db.Integer, nullable=False)
+    frequency = db.Column(db.Integer, nullable=False)
+    label = db.Column(db.String(500), nullable=False)
+    value = db.Column(db.Numeric(15, 2), nullable=False)
     account_id = db.Column(db.Integer, db.ForeignKey('account.id'))
 
-    account = db.relationship(Account, backref = db.backref('scheduled_operation', lazy="dynamic"))
+    account = db.relationship(Account, backref=db.backref('scheduled_operation',
+                                                          lazy="dynamic"))
 
-    category = db.Column(db.String(100), nullable = True)
+    category = db.Column(db.String(100), nullable=True)
 
-    def __init__(self, start_date, stop_date, day, frequency, label, value, account_id, category = None):
+    def __init__(self, start_date, stop_date, day, frequency, label, value,
+                 account_id, category=None):
         self.start_date = start_date
         self.stop_date = stop_date
         self.day = day
@@ -27,4 +44,3 @@ class ScheduledOperation(db.Model):
         self.value = value
         self.account_id = account_id
         self.category = category
-