diff --git a/eopayment/__init__.py b/eopayment/__init__.py
index 9b82803..8116ee4 100644
--- a/eopayment/__init__.py
+++ b/eopayment/__init__.py
@@ -17,24 +17,25 @@
 import datetime
 import importlib
 import logging
+
 import pytz
 
 from .common import (  # noqa: F401
-    URL,
-    HTML,
-    FORM,
-    RECEIVED,
     ACCEPTED,
-    PAID,
-    DENIED,
     CANCELED,
     CANCELLED,
+    DENIED,
     ERROR,
-    WAITING,
     EXPIRED,
-    force_text,
-    ResponseError,
+    FORM,
+    HTML,
+    PAID,
+    RECEIVED,
+    URL,
+    WAITING,
     PaymentException,
+    ResponseError,
+    force_text,
 )
 
 __all__ = [
diff --git a/eopayment/__main__.py b/eopayment/__main__.py
index ebbf158..5838a2a 100644
--- a/eopayment/__main__.py
+++ b/eopayment/__main__.py
@@ -25,7 +25,7 @@ import tempfile
 
 import click
 
-from . import Payment, FORM, URL
+from . import FORM, URL, Payment
 
 
 def option(value):
diff --git a/eopayment/cb.py b/eopayment/cb.py
index d409394..2497dc5 100644
--- a/eopayment/cb.py
+++ b/eopayment/cb.py
@@ -16,8 +16,7 @@
 
 '''Responses codes emitted by EMV Card or 'Carte Bleu' in France'''
 
-from . import PAID, CANCELLED, ERROR, DENIED
-
+from . import CANCELLED, DENIED, ERROR, PAID
 
 CB_RESPONSE_CODES = {
     '00': {'message': 'Transaction approuvée ou traitée avec succès', 'result': PAID},
diff --git a/eopayment/common.py b/eopayment/common.py
index 750c5f9..cd0299b 100644
--- a/eopayment/common.py
+++ b/eopayment/common.py
@@ -14,21 +14,18 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import os.path
+import html
+import logging
 import os
+import os.path
 import random
 import sys
-import logging
 from datetime import date
 from decimal import ROUND_DOWN, Decimal
+from gettext import gettext as _
 
 import six
 
-import html
-
-
-from gettext import gettext as _
-
 try:
     if 'django' in sys.modules:
         from django.utils.translation import ugettext_lazy as _
diff --git a/eopayment/dummy.py b/eopayment/dummy.py
index ef46ce1..2c67de1 100644
--- a/eopayment/dummy.py
+++ b/eopayment/dummy.py
@@ -20,7 +20,7 @@ import warnings
 
 from six.moves.urllib.parse import parse_qs, urlencode
 
-from .common import PaymentCommon, PaymentResponse, ResponseError, URL, PAID, ERROR, WAITING, force_text, _
+from .common import ERROR, PAID, URL, WAITING, PaymentCommon, PaymentResponse, ResponseError, _, force_text
 
 __all__ = ['Payment']
 
diff --git a/eopayment/mollie.py b/eopayment/mollie.py
index 79e2a21..efc6dc1 100644
--- a/eopayment/mollie.py
+++ b/eopayment/mollie.py
@@ -14,22 +14,21 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from .common import _
-
 import requests
 from six.moves.urllib.parse import parse_qs, urljoin
 
 from .common import (
+    ACCEPTED,
     CANCELLED,
     ERROR,
     PAID,
     URL,
+    WAITING,
     PaymentCommon,
     PaymentException,
     PaymentResponse,
     ResponseError,
-    WAITING,
-    ACCEPTED,
+    _,
 )
 
 __all__ = ['Payment']
diff --git a/eopayment/ogone.py b/eopayment/ogone.py
index 9910c9a..3c5933e 100644
--- a/eopayment/ogone.py
+++ b/eopayment/ogone.py
@@ -14,30 +14,30 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from decimal import Decimal, ROUND_HALF_UP
-from six.moves.urllib import parse as urlparse
 import hashlib
 import uuid
+from decimal import ROUND_HALF_UP, Decimal
+
+from six.moves.urllib import parse as urlparse
 
 from .common import (
+    ACCEPTED,
+    CANCELLED,
+    DENIED,
+    ERROR,
+    FORM,
+    ORDERID_TRANSACTION_SEPARATOR,
+    PAID,
+    WAITING,
+    Form,
     PaymentCommon,
     PaymentResponse,
-    FORM,
-    CANCELLED,
-    PAID,
-    ERROR,
-    Form,
-    DENIED,
-    ACCEPTED,
-    ORDERID_TRANSACTION_SEPARATOR,
-    WAITING,
     ResponseError,
+    _,
     force_byte,
     force_text,
-    _,
 )
 
-
 ENVIRONMENT_TEST = 'TEST'
 ENVIRONMENT_TEST_URL = 'https://secure.ogone.com/ncol/test/orderstandard.asp'
 ENVIRONMENT_PROD = 'PROD'
diff --git a/eopayment/paybox.py b/eopayment/paybox.py
index 31c671b..cffec55 100644
--- a/eopayment/paybox.py
+++ b/eopayment/paybox.py
@@ -14,43 +14,40 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import base64
 import codecs
-from collections import OrderedDict
 import datetime
-import logging
 import hashlib
 import hmac
+import logging
 import re
-import requests
 import uuid
+import warnings
+from collections import OrderedDict
 
 import pytz
-
-from Crypto.Signature import PKCS1_v1_5
-from Crypto.PublicKey import RSA
+import requests
 from Crypto.Hash import SHA
-
-from six.moves.urllib import parse as urlparse
+from Crypto.PublicKey import RSA
+from Crypto.Signature import PKCS1_v1_5
 from six.moves.urllib import parse as urllib
+from six.moves.urllib import parse as urlparse
 
-import base64
-import warnings
-
+from . import cb
 from .common import (
-    PaymentCommon,
-    PaymentResponse,
-    FORM,
-    PAID,
     CANCELLED,
     DENIED,
     ERROR,
+    FORM,
+    PAID,
     Form,
+    PaymentCommon,
+    PaymentResponse,
     ResponseError,
-    force_text,
-    force_byte,
     _,
+    force_byte,
+    force_text,
 )
-from . import cb
 
 __all__ = ['sign', 'Payment']
 
diff --git a/eopayment/payfip_ws.py b/eopayment/payfip_ws.py
index 16e2c34..65fbaf8 100644
--- a/eopayment/payfip_ws.py
+++ b/eopayment/payfip_ws.py
@@ -16,40 +16,38 @@
 
 
 import copy
-import decimal
 import datetime
+import decimal
 import functools
 import os
 import random
 import re
-import requests
 import unicodedata
 import xml.etree.ElementTree as ET
 
 import pytz
-
+import requests
 import six
-from six.moves.urllib.parse import parse_qs
-
 import zeep
 import zeep.exceptions
+from six.moves.urllib.parse import parse_qs
 
-from .systempayv2 import isonow
 from .common import (
-    PaymentCommon,
-    PaymentResponse,
-    URL,
-    PAID,
-    DENIED,
     CANCELLED,
+    DENIED,
     ERROR,
-    ResponseError,
-    PaymentException,
-    WAITING,
     EXPIRED,
-    force_text,
+    PAID,
+    URL,
+    WAITING,
+    PaymentCommon,
+    PaymentException,
+    PaymentResponse,
+    ResponseError,
     _,
+    force_text,
 )
+from .systempayv2 import isonow
 
 # The URL of the WSDL published in the documentation is still wrong, it
 # references XSD files which are not resolvable :/ we must use this other URL
diff --git a/eopayment/saga.py b/eopayment/saga.py
index ca8aad9..243aeb2 100644
--- a/eopayment/saga.py
+++ b/eopayment/saga.py
@@ -17,22 +17,21 @@
 
 import functools
 
-from six.moves.urllib.parse import urljoin, parse_qs
-
 import lxml.etree as ET
 import zeep
 import zeep.exceptions
+from six.moves.urllib.parse import parse_qs, urljoin
 
 from .common import (
-    PaymentException,
-    PaymentCommon,
-    ResponseError,
-    URL,
-    PAID,
-    DENIED,
     CANCELLED,
+    DENIED,
     ERROR,
+    PAID,
+    URL,
+    PaymentCommon,
+    PaymentException,
     PaymentResponse,
+    ResponseError,
 )
 
 _zeep_transport = None
diff --git a/eopayment/sips2.py b/eopayment/sips2.py
index 131f9d6..82d895f 100644
--- a/eopayment/sips2.py
+++ b/eopayment/sips2.py
@@ -14,31 +14,29 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import datetime
 import collections
+import datetime
 import hashlib
 import hmac
 import json
 import uuid
 import warnings
 
+import pytz
+import requests
 from six.moves.urllib import parse as urlparse
 
-import requests
-
-import pytz
-
 from .common import (
-    PaymentCommon,
-    FORM,
-    Form,
-    PaymentResponse,
-    PAID,
-    ERROR,
     CANCELED,
+    ERROR,
+    FORM,
+    PAID,
+    Form,
+    PaymentCommon,
+    PaymentResponse,
     ResponseError,
-    force_text,
     _,
+    force_text,
 )
 
 __all__ = ['Payment']
diff --git a/eopayment/systempayv2.py b/eopayment/systempayv2.py
index a2a7e1a..45f5bfd 100644
--- a/eopayment/systempayv2.py
+++ b/eopayment/systempayv2.py
@@ -15,31 +15,32 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import base64
-import pytz
 import datetime as dt
 import hashlib
 import hmac
 import random
 import re
 import string
-from six.moves.urllib import parse as urlparse
 import warnings
 
+import pytz
+from six.moves.urllib import parse as urlparse
+
+from .cb import translate_cb_error_code
 from .common import (
-    PaymentCommon,
-    PaymentResponse,
-    PAID,
-    DENIED,
     CANCELLED,
+    DENIED,
     ERROR,
     FORM,
+    PAID,
     Form,
+    PaymentCommon,
+    PaymentResponse,
     ResponseError,
-    force_text,
-    force_byte,
     _,
+    force_byte,
+    force_text,
 )
-from .cb import translate_cb_error_code
 
 __all__ = ['Payment']
 
diff --git a/eopayment/tipi.py b/eopayment/tipi.py
index a056e82..4bec0ef 100644
--- a/eopayment/tipi.py
+++ b/eopayment/tipi.py
@@ -16,16 +16,15 @@
 
 import datetime
 import decimal
-import re
+import logging
 import random
+import re
+import warnings
 
 import pytz
+from six.moves.urllib.parse import parse_qs, urlencode
 
-from .common import PaymentCommon, PaymentResponse, URL, PAID, DENIED, CANCELLED, ERROR, ResponseError, _
-from six.moves.urllib.parse import urlencode, parse_qs
-
-import logging
-import warnings
+from .common import CANCELLED, DENIED, ERROR, PAID, URL, PaymentCommon, PaymentResponse, ResponseError, _
 
 __all__ = ['Payment']
 
diff --git a/setup.py b/setup.py
index 0c053af..c2116b8 100755
--- a/setup.py
+++ b/setup.py
@@ -4,25 +4,24 @@
 Setup script for eopayment
 '''
 
+import distutils
+import distutils.core
+import doctest
 import io
 import os
 import subprocess
-
-import distutils
-import distutils.core
-from distutils.command.build import build as _build
 from distutils.cmd import Command
+from distutils.command.build import build as _build
 from distutils.spawn import find_executable
+from glob import glob
+from os.path import basename
+from os.path import join as pjoin
+from os.path import splitext
+from unittest import TestLoader, TextTestRunner
 
 import setuptools
-from setuptools.command.sdist import sdist
 from setuptools.command.install_lib import install_lib as _install_lib
-
-from glob import glob
-from os.path import splitext, basename, join as pjoin
-import os
-from unittest import TextTestRunner, TestLoader
-import doctest
+from setuptools.command.sdist import sdist
 
 
 class TestCommand(distutils.core.Command):
diff --git a/tests/conftest.py b/tests/conftest.py
index ec3a2fa..f1b11fe 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -16,13 +16,11 @@
 
 import json
 
-import pytest
-
 import httmock
 import lxml.etree as ET
-
-from requests.adapters import HTTPAdapter
+import pytest
 from requests import Session
+from requests.adapters import HTTPAdapter
 
 
 def pytest_addoption(parser):
diff --git a/tests/test_base_payment.py b/tests/test_base_payment.py
index 6887ac4..9c48e11 100644
--- a/tests/test_base_payment.py
+++ b/tests/test_base_payment.py
@@ -15,8 +15,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from datetime import date, datetime, timedelta
-
 from unittest import mock
+
 import pytest
 
 import eopayment
diff --git a/tests/test_dummy.py b/tests/test_dummy.py
index ad88320..f70a402 100644
--- a/tests/test_dummy.py
+++ b/tests/test_dummy.py
@@ -14,11 +14,12 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from six.moves.urllib.parse import urlparse, parse_qs
 import datetime
 
-import eopayment
 import pytest
+from six.moves.urllib.parse import parse_qs, urlparse
+
+import eopayment
 
 
 @pytest.fixture
diff --git a/tests/test_keyware.py b/tests/test_keyware.py
index 276e62d..8ddb232 100644
--- a/tests/test_keyware.py
+++ b/tests/test_keyware.py
@@ -18,7 +18,7 @@ import json
 
 import pytest
 import requests
-from httmock import response, urlmatch, HTTMock, with_httmock, all_requests, remember_called
+from httmock import HTTMock, all_requests, remember_called, response, urlmatch, with_httmock
 
 import eopayment
 from eopayment.keyware import Payment
diff --git a/tests/test_mollie.py b/tests/test_mollie.py
index fb9e41c..38e629e 100644
--- a/tests/test_mollie.py
+++ b/tests/test_mollie.py
@@ -16,12 +16,12 @@
 
 import json
 
+import pytest
 import requests
+from httmock import remember_called, response, urlmatch, with_httmock
 
 import eopayment
-import pytest
 from eopayment.mollie import Payment
-from httmock import remember_called, response, urlmatch, with_httmock
 
 WEBHOOK_URL = 'https://callback.example.com'
 RETURN_URL = 'https://return.example.com'
diff --git a/tests/test_paybox.py b/tests/test_paybox.py
index 98ef74f..b9092b0 100644
--- a/tests/test_paybox.py
+++ b/tests/test_paybox.py
@@ -15,19 +15,17 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-import codecs
-from unittest import TestCase
-from decimal import Decimal
 import base64
-from unittest import mock
-from six.moves.urllib import parse as urllib
+import codecs
+from decimal import Decimal
+from unittest import TestCase, mock
 from xml.etree import ElementTree as ET
 
 import pytest
+from six.moves.urllib import parse as urllib
 
-import eopayment.paybox as paybox
 import eopayment
-
+import eopayment.paybox as paybox
 
 BACKEND_PARAMS = {
     'platform': 'test',
diff --git a/tests/test_payfip_ws.py b/tests/test_payfip_ws.py
index 87c29f0..d141849 100644
--- a/tests/test_payfip_ws.py
+++ b/tests/test_payfip_ws.py
@@ -18,20 +18,17 @@
 
 import datetime
 import json
-import lxml.etree as ET
 from unittest import mock
 
-import pytz
-
 import httmock
+import lxml.etree as ET
 import pytest
-
+import pytz
 from zeep.plugins import HistoryPlugin
 
 import eopayment
 from eopayment.payfip_ws import PayFiP, PayFiPError, normalize_objet
 
-
 NUMCLI = '090909'
 NOTIF_URL = 'https://notif.payfip.example.com/'
 REDIRECT_URL = 'https://redirect.payfip.example.com/'
diff --git a/tests/test_saga.py b/tests/test_saga.py
index 055d150..adc53ba 100644
--- a/tests/test_saga.py
+++ b/tests/test_saga.py
@@ -19,7 +19,6 @@
 import json
 
 import pytest
-
 import zeep.transports
 
 import eopayment
diff --git a/tests/test_sips2.py b/tests/test_sips2.py
index f5386bd..f57f43f 100644
--- a/tests/test_sips2.py
+++ b/tests/test_sips2.py
@@ -15,9 +15,10 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-import eopayment
 import pytest
 
+import eopayment
+
 
 def test_build_request():
     backend = eopayment.Payment('sips2', {})
diff --git a/tests/test_systempayv2.py b/tests/test_systempayv2.py
index af1d46a..fb3d986 100644
--- a/tests/test_systempayv2.py
+++ b/tests/test_systempayv2.py
@@ -21,8 +21,8 @@ import pytest
 from six.moves.urllib import parse as urlparse
 
 import eopayment
-from eopayment.systempayv2 import Payment, VADS_CUST_FIRST_NAME, VADS_CUST_LAST_NAME, PAID
 from eopayment import ResponseError
+from eopayment.systempayv2 import PAID, VADS_CUST_FIRST_NAME, VADS_CUST_LAST_NAME, Payment
 
 PARAMS = {
     'secret_test': '1122334455667788',
diff --git a/tests/test_tipi.py b/tests/test_tipi.py
index a92d92e..6c483e1 100644
--- a/tests/test_tipi.py
+++ b/tests/test_tipi.py
@@ -16,13 +16,13 @@
 
 import datetime
 from decimal import Decimal
-from six.moves.urllib.parse import urlparse, parse_qs
 
+import pytest
 import pytz
+from six.moves.urllib.parse import parse_qs, urlparse
 
 import eopayment
 import eopayment.tipi
-import pytest
 
 
 def test_tipi():