diff --git a/.isort.cfg b/.isort.cfg
deleted file mode 100644
index 52591e45..00000000
--- a/.isort.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-[settings]
-known_first_party=sqlalchemy_utils,tests
-line_length=79
-multi_line_output=3
-not_skip=__init__.py
-order_by_type=false
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 00000000..a9421a8f
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,19 @@
+repos:
+-   repo: https://gitlab.com/pycqa/flake8
+    rev: 3.7.9
+    hooks:
+    - id: flake8
+
+-   repo: https://github.com/pre-commit/mirrors-isort
+    rev: v4.3.21
+    hooks:
+    -   id: isort
+
+
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v2.4.0
+    hooks:
+    -   id: trailing-whitespace
+    -   id: end-of-file-fixer
+    -   id: check-yaml
+    -   id: check-added-large-files
diff --git a/.travis.yml b/.travis.yml
index 977df9ef..5e70ebcd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,6 @@
 language: python
 matrix:
   include:
-    - python: 3.4
     - python: 3.5
     - python: 3.6
     - python: 3.7
@@ -9,8 +8,7 @@ matrix:
       sudo: true
     - python: pypy3
 install:
-  - pip install -e ".[test]"
+  - make install
 script:
-  - isort --recursive --diff validators tests && isort --recursive --check-only validators tests
-  - flake8 validators tests
-  - py.test --doctest-glob="*.rst" --doctest-modules --ignore=setup.py
+  - make lint
+  - make test
diff --git a/Makefile b/Makefile
new file mode 100644
index 00000000..026c22d1
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,11 @@
+lint:
+	isort --diff validators tests
+	isort --check-only validators tests
+
+	flake8 validators tests
+
+install:
+	pip install -e ".[test]"
+
+test:
+	py.test --doctest-glob="*.rst" --doctest-modules --ignore=setup.py
diff --git a/README.rst b/README.rst
index 32f57ca4..7eaab956 100644
--- a/README.rst
+++ b/README.rst
@@ -18,6 +18,29 @@ schema.
     True
 
 
+Development
+-----------
+
+To install the package for development use the following commands,
+
+.. code-block:: bash
+
+    make install  # For installing the package
+
+    make test  # For running tests
+
+    make lint  # For checking lint
+
+
+
+Pre-commit hooks are run as soon as you commit something.
+
+To run pre-commit hooks manually
+
+.. code-block:: bash
+
+   pre-commit run --all-files
+
 Resources
 ---------
 
diff --git a/docs/conf.py b/docs/conf.py
index 43717706..ec0f32aa 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -12,14 +12,15 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys
 import os
+import sys
+
+from validators import __version__
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 sys.path.insert(0, os.path.abspath('..'))
-from validators import __version__
 
 # -- General configuration ------------------------------------------------
 
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 00000000..c5686b21
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,17 @@
+[isort]
+known_first_party=sqlalchemy_utils,tests
+line_length=88
+multi_line_output=3
+order_by_type=false
+include_trailing_comma=True
+
+[flake8]
+ignore = D10,E203,E501,W503,E231,E265,W504,E122,E121
+max-line-length = 88
+select = A,B,C4,D,E,F,M,Q,T,W,ABS,BLK
+inline-quotes = "
+docstring-convention = google
+exclude =
+    .git,
+    __pycache__,
+    src/validators/libs
diff --git a/setup.py b/setup.py
index c1a5b80f..e0be793e 100644
--- a/setup.py
+++ b/setup.py
@@ -6,11 +6,11 @@
 Python Data Validation for Humans™.
 """
 
-from setuptools import setup, find_packages
 import os
 import re
 import sys
 
+from setuptools import find_packages, setup
 
 PY3 = sys.version_info[0] == 3
 HERE = os.path.dirname(os.path.abspath(__file__))
@@ -23,13 +23,8 @@ def get_version():
     pattern = r"^__version__ = '(.*?)'$"
     return re.search(pattern, contents, re.MULTILINE).group(1)
 
-
 extras_require = {
-    'test': [
-        'pytest>=2.2.3',
-        'flake8>=2.4.0',
-        'isort>=4.2.2'
-    ],
+    'test': ['pytest>=2.2.3', 'flake8>=2.4.0', 'isort>=4.2.2', 'pre-commit',],
 }
 
 install_requires = [
@@ -67,7 +62,7 @@ def get_version():
         'Programming Language :: Python :: Implementation :: CPython',
         'Programming Language :: Python :: Implementation :: PyPy',
         'Topic :: Internet :: WWW/HTTP :: Dynamic Content',
-        'Topic :: Software Development :: Libraries :: Python Modules'
+        'Topic :: Software Development :: Libraries :: Python Modules',
     ],
-    python_requires='>=3.4'
+    python_requires='>=3.4',
 )
diff --git a/tests/i18n/test_es.py b/tests/i18n/test_es.py
index 3d955c7b..168c9e9f 100644
--- a/tests/i18n/test_es.py
+++ b/tests/i18n/test_es.py
@@ -5,101 +5,106 @@
 from validators.i18n.es import es_cif, es_doi, es_nie, es_nif
 
 
-@pytest.mark.parametrize(('value',), [
-    ('B25162520',),
-    ('U4839822F',),
-    ('B96817697',),
-    ('P7067074J',),
-    ('Q7899705C',),
-    ('C75098681',),
-    ('G76061860',),
-    ('C71345375',),
-    ('G20558169',),
-    ('U5021960I',),
-])
+@pytest.mark.parametrize(
+    ('value',),
+    [
+        ('B25162520',),
+        ('U4839822F',),
+        ('B96817697',),
+        ('P7067074J',),
+        ('Q7899705C',),
+        ('C75098681',),
+        ('G76061860',),
+        ('C71345375',),
+        ('G20558169',),
+        ('U5021960I',),
+    ],
+)
 def test_returns_true_on_valid_cif(value):
     assert es_cif(value)
 
 
-@pytest.mark.parametrize(('value',), [
-    ('12345',),
-    ('ABCDEFGHI',),
-    ('Z5021960I',),
-])
+@pytest.mark.parametrize(('value',), [('12345',), ('ABCDEFGHI',), ('Z5021960I',),])
 def test_returns_false_on_invalid_cif(value):
     result = es_cif(value)
     assert isinstance(result, ValidationFailure)
 
 
-@pytest.mark.parametrize(('value',), [
-    ('X0095892M',),
-    ('X8868108K',),
-    ('X2911154K',),
-    ('Y2584969J',),
-    ('X7536157T',),
-    ('Y5840388N',),
-    ('Z2915723H',),
-    ('Y4002236C',),
-    ('X7750702R',),
-    ('Y0408759V',),
-])
+@pytest.mark.parametrize(
+    ('value',),
+    [
+        ('X0095892M',),
+        ('X8868108K',),
+        ('X2911154K',),
+        ('Y2584969J',),
+        ('X7536157T',),
+        ('Y5840388N',),
+        ('Z2915723H',),
+        ('Y4002236C',),
+        ('X7750702R',),
+        ('Y0408759V',),
+    ],
+)
 def test_returns_true_on_valid_nie(value):
     assert es_nie(value)
 
 
-@pytest.mark.parametrize(('value',), [
-    ('K0000023T',),
-    ('L0000024R',),
-    ('M0000025W',),
-    ('00000026A',),
-    ('00000027G',),
-    ('00000028M',),
-    ('00000029Y',),
-    ('00000030F',),
-    ('00000031P',),
-    ('00000032D',),
-    ('00000033X',),
-    ('00000034B',),
-    ('00000035N',),
-    ('00000036J',),
-    ('00000037Z',),
-    ('00000038S',),
-    ('00000039Q',),
-    ('00000040V',),
-    ('00000041H',),
-    ('00000042L',),
-    ('00000043C',),
-    ('00000044K',),
-    ('00000045E',),
-])
+@pytest.mark.parametrize(
+    ('value',),
+    [
+        ('K0000023T',),
+        ('L0000024R',),
+        ('M0000025W',),
+        ('00000026A',),
+        ('00000027G',),
+        ('00000028M',),
+        ('00000029Y',),
+        ('00000030F',),
+        ('00000031P',),
+        ('00000032D',),
+        ('00000033X',),
+        ('00000034B',),
+        ('00000035N',),
+        ('00000036J',),
+        ('00000037Z',),
+        ('00000038S',),
+        ('00000039Q',),
+        ('00000040V',),
+        ('00000041H',),
+        ('00000042L',),
+        ('00000043C',),
+        ('00000044K',),
+        ('00000045E',),
+    ],
+)
 def test_returns_true_on_valid_nif(value):
     assert es_nif(value)
 
 
-@pytest.mark.parametrize(('value',), [
-    ('12345',),
-    ('X0000000T',),
-    ('00000000T',),
-    ('00000001R',),
-])
+@pytest.mark.parametrize(
+    ('value',), [('12345',), ('X0000000T',), ('00000000T',), ('00000001R',),]
+)
 def test_returns_false_on_invalid_nif(value):
     result = es_nif(value)
     assert isinstance(result, ValidationFailure)
 
 
-@pytest.mark.parametrize(('value',), [
-    # CIFs
-    ('B25162520',),
-    ('U4839822F',),
-    ('B96817697',),
-    # NIEs
-    ('X0095892M',),
-    ('X8868108K',),
-    ('X2911154K',),
-    # NIFs
-    ('26643189N',),
-    ('07060225F',),
-    ('49166693F',),
-])
+@pytest.mark.parametrize(
+    ('value',),
+    [
+        # CIFs
+        ('B25162520',),
+        ('U4839822F',),
+        ('B96817697',),
+        # NIEs
+        ('X0095892M',),
+        ('X8868108K',),
+        ('X2911154K',),
+        # NIFs
+        ('26643189N',),
+        ('07060225F',),
+        ('49166693F',),
+    ],
+)
 def test_returns_true_on_valid_doi(value):
     assert es_doi(value)
diff --git a/tests/i18n/test_fi.py b/tests/i18n/test_fi.py
index b900bc4e..0557a614 100644
--- a/tests/i18n/test_fi.py
+++ b/tests/i18n/test_fi.py
@@ -5,56 +5,60 @@
 from validators.i18n.fi import fi_business_id, fi_ssn
 
 
-@pytest.mark.parametrize(('value',), [
-    ('2336509-6',),  # Supercell
-    ('0112038-9',),  # Fast Monkeys
-    ('2417581-7',),  # Nokia
-])
+@pytest.mark.parametrize(
+    ('value',),
+    [
+        ('2336509-6',),  # Supercell
+        ('0112038-9',),  # Fast Monkeys
+        ('2417581-7',),  # Nokia
+    ],
+)
 def test_returns_true_on_valid_business_id(value):
     assert fi_business_id(value)
 
 
-@pytest.mark.parametrize(('value',), [
-    (None,),
-    ('',),
-    ('1233312312',),
-    ('1333333-8',),
-    ('1231233-9',),
-])
+@pytest.mark.parametrize(
+    ('value',), [(None,), ('',), ('1233312312',), ('1333333-8',), ('1231233-9',),]
+)
 def test_returns_failed_validation_on_invalid_business_id(value):
     assert isinstance(fi_business_id(value), ValidationFailure)
 
 
-@pytest.mark.parametrize(('value',), [
-    ('010190-002R',),
-    ('010101-0101',),
-    ('010101+0101',),
-    ('010101A0101',),
-    ('010190-900P',),
-])
+@pytest.mark.parametrize(
+    ('value',),
+    [
+        ('010190-002R',),
+        ('010101-0101',),
+        ('010101+0101',),
+        ('010101A0101',),
+        ('010190-900P',),
+    ],
+)
 def test_returns_true_on_valid_ssn(value):
     assert fi_ssn(value)
 
 
-@pytest.mark.parametrize(('value',), [
-    (None,),
-    ('',),
-    ('010190-001P',),  # Too low serial
-    ('010190-000N',),  # Too low serial
-    ('000190-0023',),  # Invalid day
-    ('010090-002X',),  # Invalid month
-    ('010190-002r',),  # Invalid checksum
-    ('101010-0102',),
-    ('10a010-0101',),
-    ('101010-0\xe401',),
-    ('101010b0101',)
-])
+@pytest.mark.parametrize(
+    ('value',),
+    [
+        (None,),
+        ('',),
+        ('010190-001P',),  # Too low serial
+        ('010190-000N',),  # Too low serial
+        ('000190-0023',),  # Invalid day
+        ('010090-002X',),  # Invalid month
+        ('010190-002r',),  # Invalid checksum
+        ('101010-0102',),
+        ('10a010-0101',),
+        ('101010-0\xe401',),
+        ('101010b0101',),
+    ],
+)
 def test_returns_failed_validation_on_invalid_ssn(value):
     assert isinstance(fi_ssn(value), ValidationFailure)
 
 
 def test_returns_failed_validation_on_temporal_ssn_when_not_allowed():
     assert isinstance(
-        fi_ssn('010190-900P', allow_temporal_ssn=False),
-        ValidationFailure
+        fi_ssn('010190-900P', allow_temporal_ssn=False), ValidationFailure
     )
diff --git a/tests/test_between.py b/tests/test_between.py
index 45f0eeeb..ee10f9b8 100644
--- a/tests/test_between.py
+++ b/tests/test_between.py
@@ -4,30 +4,23 @@
 import validators
 
 
-@pytest.mark.parametrize(('value', 'min', 'max'), [
-    (12, 11, 13),
-    (12, None, 14),
-    (12, 11, None),
-    (12, 12, 12)
-])
+@pytest.mark.parametrize(
+    ('value', 'min', 'max'),
+    [(12, 11, 13), (12, None, 14), (12, 11, None), (12, 12, 12)],
+)
 def test_returns_true_on_valid_range(value, min, max):
     assert validators.between(value, min=min, max=max)
 
 
-@pytest.mark.parametrize(('value', 'min', 'max'), [
-    (12, 13, 12),
-    (12, None, None),
-])
+@pytest.mark.parametrize(('value', 'min', 'max'), [(12, 13, 12), (12, None, None),])
 def test_raises_assertion_error_for_invalid_args(value, min, max):
     with pytest.raises(AssertionError):
         assert validators.between(value, min=min, max=max)
 
 
-@pytest.mark.parametrize(('value', 'min', 'max'), [
-    (12, 13, 14),
-    (12, None, 11),
-    (12, 13, None)
-])
+@pytest.mark.parametrize(
+    ('value', 'min', 'max'), [(12, 13, 14), (12, None, 11), (12, 13, None)]
+)
 def test_returns_failed_validation_on_invalid_range(value, min, max):
     result = validators.between(value, min=min, max=max)
     assert isinstance(result, validators.ValidationFailure)
diff --git a/tests/test_card.py b/tests/test_card.py
index d76dbcf2..378658c3 100644
--- a/tests/test_card.py
+++ b/tests/test_card.py
@@ -10,39 +10,20 @@
     mastercard,
     unionpay,
     ValidationFailure,
-    visa
+    visa,
 )
 
-visa_cards = [
-    '4242424242424242',
-    '4000002760003184'
-]
-mastercard_cards = [
-    '5555555555554444',
-    '2223003122003222'
-]
-amex_cards = [
-    '378282246310005',
-    '371449635398431'
-]
-unionpay_cards = [
-    '6200000000000005'
-]
-diners_cards = [
-    '3056930009020004',
-    '36227206271667'
-]
-jcb_cards = [
-    '3566002020360505'
-]
-discover_cards = [
-    '6011111111111117',
-    '6011000990139424'
-]
+visa_cards = ['4242424242424242', '4000002760003184']
+mastercard_cards = ['5555555555554444', '2223003122003222']
+amex_cards = ['378282246310005', '371449635398431']
+unionpay_cards = ['6200000000000005']
+diners_cards = ['3056930009020004', '36227206271667']
+jcb_cards = ['3566002020360505']
+discover_cards = ['6011111111111117', '6011000990139424']
 
 
 @pytest.mark.parametrize(
-    "value",
+    'value',
     visa_cards
     + mastercard_cards
     + amex_cards
@@ -55,11 +36,9 @@ def test_returns_true_on_valid_card_number(value):
     assert card_number(value)
 
 
-@pytest.mark.parametrize('value', [
-    '4242424242424240',
-    '4000002760003180',
-    '400000276000318X'
-])
+@pytest.mark.parametrize(
+    'value', ['4242424242424240', '4000002760003180', '400000276000318X']
+)
 def test_returns_failed_on_valid_card_number(value):
     assert isinstance(card_number(value), ValidationFailure)
 
@@ -70,7 +49,7 @@ def test_returns_true_on_valid_visa(value):
 
 
 @pytest.mark.parametrize(
-    "value",
+    'value',
     mastercard_cards
     + amex_cards
     + unionpay_cards
@@ -88,7 +67,7 @@ def test_returns_true_on_valid_mastercard(value):
 
 
 @pytest.mark.parametrize(
-    "value",
+    'value',
     visa_cards
     + amex_cards
     + unionpay_cards
@@ -106,7 +85,7 @@ def test_returns_true_on_valid_amex(value):
 
 
 @pytest.mark.parametrize(
-    "value",
+    'value',
     visa_cards
     + mastercard_cards
     + unionpay_cards
@@ -124,7 +103,7 @@ def test_returns_true_on_valid_unionpay(value):
 
 
 @pytest.mark.parametrize(
-    "value",
+    'value',
     visa_cards
     + mastercard_cards
     + amex_cards
@@ -142,7 +121,7 @@ def test_returns_true_on_valid_diners(value):
 
 
 @pytest.mark.parametrize(
-    "value",
+    'value',
     visa_cards
     + mastercard_cards
     + amex_cards
@@ -160,7 +139,7 @@ def test_returns_true_on_valid_jcb(value):
 
 
 @pytest.mark.parametrize(
-    "value",
+    'value',
     visa_cards
     + mastercard_cards
     + amex_cards
@@ -178,7 +157,7 @@ def test_returns_true_on_valid_discover(value):
 
 
 @pytest.mark.parametrize(
-    "value",
+    'value',
     visa_cards
     + mastercard_cards
     + amex_cards
diff --git a/tests/test_domain.py b/tests/test_domain.py
index f8fe35b3..eefc8784 100644
--- a/tests/test_domain.py
+++ b/tests/test_domain.py
@@ -4,39 +4,45 @@
 from validators import domain, ValidationFailure
 
 
-@pytest.mark.parametrize('value', [
-    'example.com',
-    'xn----gtbspbbmkef.xn--p1ai',
-    'underscore_subdomain.example.com',
-    'something.versicherung',
-    'someThing.versicherung',
-    '11.com',
-    '3.cn',
-    'a.cn',
-    'sub1.sub2.sample.co.uk',
-    'somerandomexample.xn--fiqs8s',
-    'kräuter.com',
-    'über.com'
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        'example.com',
+        'xn----gtbspbbmkef.xn--p1ai',
+        'underscore_subdomain.example.com',
+        'something.versicherung',
+        'someThing.versicherung',
+        '11.com',
+        '3.cn',
+        'a.cn',
+        'sub1.sub2.sample.co.uk',
+        'somerandomexample.xn--fiqs8s',
+        'kräuter.com',
+        'über.com',
+    ],
+)
 def test_returns_true_on_valid_domain(value):
     assert domain(value)
 
 
-@pytest.mark.parametrize('value', [
-    'example.com/',
-    'example.com:4444',
-    'example.-com',
-    'example.',
-    '-example.com',
-    'example-.com',
-    '_example.com',
-    'example_.com',
-    'example',
-    'a......b.com',
-    'a.123',
-    '123.123',
-    '123.123.123',
-    '123.123.123.123'
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        'example.com/',
+        'example.com:4444',
+        'example.-com',
+        'example.',
+        '-example.com',
+        'example-.com',
+        '_example.com',
+        'example_.com',
+        'example',
+        'a......b.com',
+        'a.123',
+        '123.123',
+        '123.123.123',
+        '123.123.123.123',
+    ],
+)
 def test_returns_failed_validation_on_invalid_domain(value):
     assert isinstance(domain(value), ValidationFailure)
diff --git a/tests/test_email.py b/tests/test_email.py
index 0b7f4e27..8cfe576f 100644
--- a/tests/test_email.py
+++ b/tests/test_email.py
@@ -4,42 +4,48 @@
 from validators import email, ValidationFailure
 
 
-@pytest.mark.parametrize(('value', 'whitelist'), [
-    ('email@here.com', None),
-    ('weirder-email@here.and.there.com', None),
-    ('email@[127.0.0.1]', None),
-    ('example@valid-----hyphens.com', None),
-    ('example@valid-with-hyphens.com', None),
-    ('test@domain.with.idn.tld.उदाहरण.परीक्षा', None),
-    ('email@localhost', None),
-    ('email@localdomain', ['localdomain']),
-    ('"test@test"@example.com', None),
-    ('"\\\011"@here.com', None),
-])
+@pytest.mark.parametrize(
+    ('value', 'whitelist'),
+    [
+        ('email@here.com', None),
+        ('weirder-email@here.and.there.com', None),
+        ('email@[127.0.0.1]', None),
+        ('example@valid-----hyphens.com', None),
+        ('example@valid-with-hyphens.com', None),
+        ('test@domain.with.idn.tld.उदाहरण.परीक्षा', None),
+        ('email@localhost', None),
+        ('email@localdomain', ['localdomain']),
+        ('"test@test"@example.com', None),
+        ('"\\\011"@here.com', None),
+    ],
+)
 def test_returns_true_on_valid_email(value, whitelist):
     assert email(value, whitelist=whitelist)
 
 
-@pytest.mark.parametrize(('value',), [
-    (None,),
-    ('',),
-    ('abc',),
-    ('abc@',),
-    ('abc@bar',),
-    ('a @x.cz',),
-    ('abc@.com',),
-    ('something@@somewhere.com',),
-    ('email@127.0.0.1',),
-    ('example@invalid-.com',),
-    ('example@-invalid.com',),
-    ('example@inv-.alid-.com',),
-    ('example@inv-.-alid.com',),
-    (
-        'john56789.john56789.john56789.john56789.john56789.john56789.john5'
-        '@example.com',
-    ),
-    # Quoted-string format (CR not allowed)
-    ('"\\\012"@here.com',),
-])
+@pytest.mark.parametrize(
+    ('value',),
+    [
+        (None,),
+        ('',),
+        ('abc',),
+        ('abc@',),
+        ('abc@bar',),
+        ('a @x.cz',),
+        ('abc@.com',),
+        ('something@@somewhere.com',),
+        ('email@127.0.0.1',),
+        ('example@invalid-.com',),
+        ('example@-invalid.com',),
+        ('example@inv-.alid-.com',),
+        ('example@inv-.-alid.com',),
+        (
+            'john56789.john56789.john56789.john56789.john56789.john56789.john5'
+            '@example.com',
+        ),
+        # Quoted-string format (CR not allowed)
+        ('"\\\012"@here.com',),
+    ],
+)
 def test_returns_failed_validation_on_invalid_email(value):
     assert isinstance(email(value), ValidationFailure)
diff --git a/tests/test_extremes.py b/tests/test_extremes.py
index d9f5023c..5bc1e0e3 100644
--- a/tests/test_extremes.py
+++ b/tests/test_extremes.py
@@ -4,12 +4,7 @@
 from validators import Max, Min
 
 
-@pytest.mark.parametrize(('value',), [
-    (None,),
-    ('',),
-    (12,),
-    (Min,),
-])
+@pytest.mark.parametrize(('value',), [(None,), ('',), (12,), (Min,),])
 def test_max_is_greater_than_every_other_value(value):
     assert value < Max
     assert Max > value
@@ -25,12 +20,7 @@ def test_other_comparison_methods_for_max():
     assert not (Max != Max)
 
 
-@pytest.mark.parametrize(('value',), [
-    (None,),
-    ('',),
-    (12,),
-    (Max,),
-])
+@pytest.mark.parametrize(('value',), [(None,), ('',), (12,), (Max,),])
 def test_min_is_smaller_than_every_other_value(value):
     assert value > Min
 
diff --git a/tests/test_iban.py b/tests/test_iban.py
index 2dcca652..26aa2557 100644
--- a/tests/test_iban.py
+++ b/tests/test_iban.py
@@ -4,18 +4,12 @@
 import validators
 
 
-@pytest.mark.parametrize('value', [
-    'GB82WEST12345698765432',
-    'NO9386011117947'
-])
+@pytest.mark.parametrize('value', ['GB82WEST12345698765432', 'NO9386011117947'])
 def test_returns_true_on_valid_iban(value):
     assert validators.iban(value)
 
 
-@pytest.mark.parametrize('value', [
-    'GB81WEST12345698765432',
-    'NO9186011117947'
-])
+@pytest.mark.parametrize('value', ['GB81WEST12345698765432', 'NO9186011117947'])
 def test_returns_failed_validation_on_invalid_iban(value):
     result = validators.iban(value)
     assert isinstance(result, validators.ValidationFailure)
diff --git a/tests/test_ipv4.py b/tests/test_ipv4.py
index 3dac98d8..829cdc1e 100644
--- a/tests/test_ipv4.py
+++ b/tests/test_ipv4.py
@@ -4,21 +4,17 @@
 from validators import ipv4, ipv6, ValidationFailure
 
 
-@pytest.mark.parametrize(('address',), [
-    ('127.0.0.1',),
-    ('123.5.77.88',),
-    ('12.12.12.12',),
-])
+@pytest.mark.parametrize(
+    ('address',), [('127.0.0.1',), ('123.5.77.88',), ('12.12.12.12',),]
+)
 def test_returns_true_on_valid_ipv4_address(address):
     assert ipv4(address)
     assert not ipv6(address)
 
 
-@pytest.mark.parametrize(('address',), [
-    ('abc.0.0.1',),
-    ('1278.0.0.1',),
-    ('127.0.0.abc',),
-    ('900.200.100.75',),
-])
+@pytest.mark.parametrize(
+    ('address',),
+    [('abc.0.0.1',), ('1278.0.0.1',), ('127.0.0.abc',), ('900.200.100.75',),],
+)
 def test_returns_failed_validation_on_invalid_ipv4_address(address):
     assert isinstance(ipv4(address), ValidationFailure)
diff --git a/tests/test_ipv4_cidr.py b/tests/test_ipv4_cidr.py
index 3216a17a..eb130baa 100644
--- a/tests/test_ipv4_cidr.py
+++ b/tests/test_ipv4_cidr.py
@@ -4,22 +4,17 @@
 from validators import ipv4_cidr, ipv6_cidr, ValidationFailure
 
 
-@pytest.mark.parametrize(('cidr',), [
-    ('127.0.0.1/0',),
-    ('123.5.77.88/8',),
-    ('12.12.12.12/32',),
-])
+@pytest.mark.parametrize(
+    ('cidr',), [('127.0.0.1/0',), ('123.5.77.88/8',), ('12.12.12.12/32',),]
+)
 def test_returns_true_on_valid_ipv4_cidr(cidr):
     assert ipv4_cidr(cidr)
     assert not ipv6_cidr(cidr)
 
 
-@pytest.mark.parametrize(('cidr',), [
-    ('abc.0.0.1',),
-    ('1.1.1.1',),
-    ('1.1.1.1/-1',),
-    ('1.1.1.1/33',),
-    ('1.1.1.1/foo',),
-])
+@pytest.mark.parametrize(
+    ('cidr',),
+    [('abc.0.0.1',), ('1.1.1.1',), ('1.1.1.1/-1',), ('1.1.1.1/33',), ('1.1.1.1/foo',),],
+)
 def test_returns_failed_validation_on_invalid_ipv4_cidr(cidr):
     assert isinstance(ipv4_cidr(cidr), ValidationFailure)
diff --git a/tests/test_ipv6.py b/tests/test_ipv6.py
index 3f321404..4c650e9c 100644
--- a/tests/test_ipv6.py
+++ b/tests/test_ipv6.py
@@ -4,23 +4,24 @@
 from validators import ipv4, ipv6, ValidationFailure
 
 
-@pytest.mark.parametrize(('address',), [
-    ('::1',),
-    ('dead:beef:0:0:0:0:42:1',),
-    ('abcd:ef::42:1',),
-    ('0:0:0:0:0:ffff:1.2.3.4',),
-    ('::192.168.30.2',),
-])
+@pytest.mark.parametrize(
+    ('address',),
+    [
+        ('::1',),
+        ('dead:beef:0:0:0:0:42:1',),
+        ('abcd:ef::42:1',),
+        ('0:0:0:0:0:ffff:1.2.3.4',),
+        ('::192.168.30.2',),
+    ],
+)
 def test_returns_true_on_valid_ipv6_address(address):
     assert ipv6(address)
     assert not ipv4(address)
 
 
-@pytest.mark.parametrize(('address',), [
-    ('abc.0.0.1',),
-    ('abcd:1234::123::1',),
-    ('1:2:3:4:5:6:7:8:9',),
-    ('abcd::1ffff',),
-])
+@pytest.mark.parametrize(
+    ('address',),
+    [('abc.0.0.1',), ('abcd:1234::123::1',), ('1:2:3:4:5:6:7:8:9',), ('abcd::1ffff',),],
+)
 def test_returns_failed_validation_on_invalid_ipv6_address(address):
     assert isinstance(ipv6(address), ValidationFailure)
diff --git a/tests/test_ipv6_cidr.py b/tests/test_ipv6_cidr.py
index 308390a9..cd28206d 100644
--- a/tests/test_ipv6_cidr.py
+++ b/tests/test_ipv6_cidr.py
@@ -4,28 +4,34 @@
 from validators import ipv4_cidr, ipv6_cidr, ValidationFailure
 
 
-@pytest.mark.parametrize(('cidr',), [
-    ('::1/0',),
-    ('dead:beef:0:0:0:0:42:1/8',),
-    ('abcd:ef::42:1/32',),
-    ('0:0:0:0:0:ffff:1.2.3.4/64',),
-    ('::192.168.30.2/128',),
-])
+@pytest.mark.parametrize(
+    ('cidr',),
+    [
+        ('::1/0',),
+        ('dead:beef:0:0:0:0:42:1/8',),
+        ('abcd:ef::42:1/32',),
+        ('0:0:0:0:0:ffff:1.2.3.4/64',),
+        ('::192.168.30.2/128',),
+    ],
+)
 def test_returns_true_on_valid_ipv6_cidr(cidr):
     assert ipv6_cidr(cidr)
     assert not ipv4_cidr(cidr)
 
 
-@pytest.mark.parametrize(('cidr',), [
-    ('abc.0.0.1',),
-    ('abcd:1234::123::1',),
-    ('1:2:3:4:5:6:7:8:9',),
-    ('abcd::1ffff',),
-    ('1.1.1.1',),
-    ('::1',),
-    ('::1/129',),
-    ('::1/-1',),
-    ('::1/foo',),
-])
+@pytest.mark.parametrize(
+    ('cidr',),
+    [
+        ('abc.0.0.1',),
+        ('abcd:1234::123::1',),
+        ('1:2:3:4:5:6:7:8:9',),
+        ('abcd::1ffff',),
+        ('1.1.1.1',),
+        ('::1',),
+        ('::1/129',),
+        ('::1/-1',),
+        ('::1/foo',),
+    ],
+)
 def test_returns_failed_validation_on_invalid_ipv6_cidr(cidr):
     assert isinstance(ipv6_cidr(cidr), ValidationFailure)
diff --git a/tests/test_length.py b/tests/test_length.py
index 86342f1e..04a04438 100644
--- a/tests/test_length.py
+++ b/tests/test_length.py
@@ -4,34 +4,38 @@
 import validators
 
 
-@pytest.mark.parametrize(('value', 'min', 'max'), [
-    ('password', 2, 10),
-    ('password', None, 10),
-    ('password', 2, None),
-    ('password', 8, 8)
-])
+@pytest.mark.parametrize(
+    ('value', 'min', 'max'),
+    [
+        ('password', 2, 10),
+        ('password', None, 10),
+        ('password', 2, None),
+        ('password', 8, 8),
+    ],
+)
 def test_returns_true_on_valid_length(value, min, max):
     assert validators.length(value, min=min, max=max)
 
 
-@pytest.mark.parametrize(('value', 'min', 'max'), [
-    ('something', 13, 12),
-    ('something', -1, None),
-    ('something', -1, None),
-    ('something', -3, -2)
-])
+@pytest.mark.parametrize(
+    ('value', 'min', 'max'),
+    [
+        ('something', 13, 12),
+        ('something', -1, None),
+        ('something', -1, None),
+        ('something', -3, -2),
+    ],
+)
 def test_raises_assertion_error_for_invalid_args(value, min, max):
     with pytest.raises(AssertionError):
         assert validators.length(value, min=min, max=max)
 
 
-@pytest.mark.parametrize(('value', 'min', 'max'), [
-    ('something', 13, 14),
-    ('something', None, 6),
-    ('something', 13, None)
-])
+@pytest.mark.parametrize(
+    ('value', 'min', 'max'),
+    [('something', 13, 14), ('something', None, 6), ('something', 13, None)],
+)
 def test_returns_failed_validation_on_invalid_range(value, min, max):
     assert isinstance(
-        validators.length(value, min=min, max=max),
-        validators.ValidationFailure
+        validators.length(value, min=min, max=max), validators.ValidationFailure
     )
diff --git a/tests/test_mac_address.py b/tests/test_mac_address.py
index 756fa3ec..3eaeaf0d 100644
--- a/tests/test_mac_address.py
+++ b/tests/test_mac_address.py
@@ -4,18 +4,19 @@
 from validators import mac_address, ValidationFailure
 
 
-@pytest.mark.parametrize(('address',), [
-    ('01:23:45:67:ab:CD',),
-])
+@pytest.mark.parametrize(('address',), [('01:23:45:67:ab:CD',),])
 def test_returns_true_on_valid_mac_address(address):
     assert mac_address(address)
 
 
-@pytest.mark.parametrize(('address',), [
-    ('00:00:00:00:00',),
-    ('01:23:45:67:89:',),
-    ('01:23:45:67:89:gh',),
-    ('123:23:45:67:89:00',),
-])
+@pytest.mark.parametrize(
+    ('address',),
+    [
+        ('00:00:00:00:00',),
+        ('01:23:45:67:89:',),
+        ('01:23:45:67:89:gh',),
+        ('123:23:45:67:89:00',),
+    ],
+)
 def test_returns_failed_validation_on_invalid_mac_address(address):
     assert isinstance(mac_address(address), ValidationFailure)
diff --git a/tests/test_md5.py b/tests/test_md5.py
index 3efb1d69..0a5fd689 100644
--- a/tests/test_md5.py
+++ b/tests/test_md5.py
@@ -4,19 +4,21 @@
 import validators
 
 
-@pytest.mark.parametrize('value', [
-    'd41d8cd98f00b204e9800998ecf8427e',
-    'D41D8CD98F00B204E9800998ECF8427E'
-])
+@pytest.mark.parametrize(
+    'value', ['d41d8cd98f00b204e9800998ecf8427e', 'D41D8CD98F00B204E9800998ECF8427E']
+)
 def test_returns_true_on_valid_md5(value):
     assert validators.md5(value)
 
 
-@pytest.mark.parametrize('value', [
-    'z41d8cd98f00b204e9800998ecf8427e',
-    'z8cd98f00b204e9800998ecf8427e',
-    'z4aaaa1d8cd98f00b204e9800998ecf8427e'
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        'z41d8cd98f00b204e9800998ecf8427e',
+        'z8cd98f00b204e9800998ecf8427e',
+        'z4aaaa1d8cd98f00b204e9800998ecf8427e',
+    ],
+)
 def test_returns_failed_validation_on_invalid_md5(value):
     result = validators.md5(value)
     assert isinstance(result, validators.ValidationFailure)
diff --git a/tests/test_sha1.py b/tests/test_sha1.py
index b729009a..727a961f 100644
--- a/tests/test_sha1.py
+++ b/tests/test_sha1.py
@@ -4,19 +4,25 @@
 import validators
 
 
-@pytest.mark.parametrize('value', [
-    'da39a3ee5e6b4b0d3255bfef95601890afd80709',
-    'DA39A3EE5E6B4B0D3255BFEF95601890AFD80709'
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        'da39a3ee5e6b4b0d3255bfef95601890afd80709',
+        'DA39A3EE5E6B4B0D3255BFEF95601890AFD80709',
+    ],
+)
 def test_returns_true_on_valid_sha1(value):
     assert validators.sha1(value)
 
 
-@pytest.mark.parametrize('value', [
-    'za39a3ee5e6b4b0d3255bfef95601890afd80709',
-    'da39e5e6b4b0d3255bfef95601890afd80709',
-    'daaaa39a3ee5e6b4b0d3255bfef95601890afd80709'
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        'za39a3ee5e6b4b0d3255bfef95601890afd80709',
+        'da39e5e6b4b0d3255bfef95601890afd80709',
+        'daaaa39a3ee5e6b4b0d3255bfef95601890afd80709',
+    ],
+)
 def test_returns_failed_validation_on_invalid_sha1(value):
     result = validators.sha1(value)
     assert isinstance(result, validators.ValidationFailure)
diff --git a/tests/test_sha224.py b/tests/test_sha224.py
index 225275b9..e508b370 100644
--- a/tests/test_sha224.py
+++ b/tests/test_sha224.py
@@ -4,19 +4,25 @@
 import validators
 
 
-@pytest.mark.parametrize('value', [
-    'd14a028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f',
-    'D14A028C2A3A2BC9476102BB288234C415A2B01F828EA62AC5B3E42F'
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        'd14a028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f',
+        'D14A028C2A3A2BC9476102BB288234C415A2B01F828EA62AC5B3E42F',
+    ],
+)
 def test_returns_true_on_valid_sha224(value):
     assert validators.sha224(value)
 
 
-@pytest.mark.parametrize('value', [
-    'z14a028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f',
-    'd028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f',
-    'daaa14a028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f'
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        'z14a028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f',
+        'd028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f',
+        'daaa14a028c2a3a2bc9476102bb288234c415a2b01f828ea62ac5b3e42f',
+    ],
+)
 def test_returns_failed_validation_on_invalid_sha224(value):
     result = validators.sha224(value)
     assert isinstance(result, validators.ValidationFailure)
diff --git a/tests/test_sha256.py b/tests/test_sha256.py
index b9c20776..8c9bbcb6 100644
--- a/tests/test_sha256.py
+++ b/tests/test_sha256.py
@@ -4,19 +4,25 @@
 import validators
 
 
-@pytest.mark.parametrize('value', [
-    'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
-    'E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855'
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
+        'E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855',
+    ],
+)
 def test_returns_true_on_valid_sha256(value):
     assert validators.sha256(value)
 
 
-@pytest.mark.parametrize('value', [
-    'z3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
-    'ec44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
-    'eaaaa3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        'z3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
+        'ec44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
+        'eaaaa3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
+    ],
+)
 def test_returns_failed_validation_on_invalid_sha256(value):
     result = validators.sha256(value)
     assert isinstance(result, validators.ValidationFailure)
diff --git a/tests/test_sha512.py b/tests/test_sha512.py
index 7a7aabba..28d2d8d7 100644
--- a/tests/test_sha512.py
+++ b/tests/test_sha512.py
@@ -4,34 +4,40 @@
 import validators
 
 
-@pytest.mark.parametrize('value', [
-    (
-        'cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d'
-        '13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e'
-    ),
-    (
-        'CF83E1357EEFB8BDF1542850D66D8007D620E4050B5715DC83F4A921D36CE9CE47D0D'
-        '13C5D85F2B0FF8318D2877EEC2F63B931BD47417A81A538327AF927DA3E'
-    )
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        (
+            'cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d'
+            '13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e'
+        ),
+        (
+            'CF83E1357EEFB8BDF1542850D66D8007D620E4050B5715DC83F4A921D36CE9CE47D0D'
+            '13C5D85F2B0FF8318D2877EEC2F63B931BD47417A81A538327AF927DA3E'
+        ),
+    ],
+)
 def test_returns_true_on_valid_sha512(value):
     assert validators.sha512(value)
 
 
-@pytest.mark.parametrize('value', [
-    (
-        'zf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d'
-        '13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e'
-    ),
-    (
-        'cf8357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c'
-        '5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e'
-    ),
-    (
-        'cf8aaaa3e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce4'
-        '7d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e'
-    )
-])
+@pytest.mark.parametrize(
+    'value',
+    [
+        (
+            'zf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d'
+            '13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e'
+        ),
+        (
+            'cf8357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c'
+            '5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e'
+        ),
+        (
+            'cf8aaaa3e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce4'
+            '7d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e'
+        ),
+    ],
+)
 def test_returns_failed_validation_on_invalid_sha512(value):
     result = validators.sha512(value)
     assert isinstance(result, validators.ValidationFailure)
diff --git a/tests/test_slug.py b/tests/test_slug.py
index a42fe5f7..8a74a780 100644
--- a/tests/test_slug.py
+++ b/tests/test_slug.py
@@ -4,20 +4,13 @@
 from validators import slug, ValidationFailure
 
 
-@pytest.mark.parametrize('value', [
-    '123-12312-asdasda',
-    '123____123',
-    'dsadasd-dsadas',
-])
+@pytest.mark.parametrize(
+    'value', ['123-12312-asdasda', '123____123', 'dsadasd-dsadas',]
+)
 def test_returns_true_on_valid_slug(value):
     assert slug(value)
 
 
-@pytest.mark.parametrize('value', [
-    'some.slug',
-    '1231321%',
-    '   21312',
-    '123asda&',
-])
+@pytest.mark.parametrize('value', ['some.slug', '1231321%', '   21312', '123asda&',])
 def test_returns_failed_validation_on_invalid_slug(value):
     assert isinstance(slug(value), ValidationFailure)
diff --git a/tests/test_uuid.py b/tests/test_uuid.py
index 42415c2a..c8258e12 100644
--- a/tests/test_uuid.py
+++ b/tests/test_uuid.py
@@ -4,18 +4,19 @@
 from validators import uuid, ValidationFailure
 
 
-@pytest.mark.parametrize(('value',), [
-    ('2bc1c94f-0deb-43e9-92a1-4775189ec9f8',),
-])
+@pytest.mark.parametrize(('value',), [('2bc1c94f-0deb-43e9-92a1-4775189ec9f8',),])
 def test_returns_true_on_valid_mac_address(value):
     assert uuid(value)
 
 
-@pytest.mark.parametrize(('value',), [
-    ('2bc1c94f-deb-43e9-92a1-4775189ec9f8',),
-    ('2bc1c94f-0deb-43e9-92a1-4775189ec9f',),
-    ('gbc1c94f-0deb-43e9-92a1-4775189ec9f8',),
-    ('2bc1c94f 0deb-43e9-92a1-4775189ec9f8',),
-])
+@pytest.mark.parametrize(
+    ('value',),
+    [
+        ('2bc1c94f-deb-43e9-92a1-4775189ec9f8',),
+        ('2bc1c94f-0deb-43e9-92a1-4775189ec9f',),
+        ('gbc1c94f-0deb-43e9-92a1-4775189ec9f8',),
+        ('2bc1c94f 0deb-43e9-92a1-4775189ec9f8',),
+    ],
+)
 def test_returns_failed_validation_on_invalid_mac_address(value):
     assert isinstance(uuid(value), ValidationFailure)
diff --git a/tests/test_validation_failure.py b/tests/test_validation_failure.py
index 0601aa6f..e3a915d6 100644
--- a/tests/test_validation_failure.py
+++ b/tests/test_validation_failure.py
@@ -2,9 +2,7 @@
 
 import validators
 
-obj_repr = (
-    "ValidationFailure(func=between"
-)
+obj_repr = ('ValidationFailure(func=between')
 
 
 class TestValidationFailure(object):
diff --git a/validators/__init__.py b/validators/__init__.py
index 7244ad9a..5b354e67 100644
--- a/validators/__init__.py
+++ b/validators/__init__.py
@@ -1,15 +1,6 @@
 from .between import between
 from .btc_address import btc_address
-from .card import (
-    amex,
-    card_number,
-    diners,
-    discover,
-    jcb,
-    mastercard,
-    unionpay,
-    visa
-)
+from .card import amex, card_number, diners, discover, jcb, mastercard, unionpay, visa
 from .domain import domain
 from .email import email
 from .extremes import Max, Min
@@ -25,11 +16,41 @@
 from .utils import ValidationFailure, validator
 from .uuid import uuid
 
-__all__ = ('between', 'domain', 'email', 'Max', 'Min', 'md5', 'sha1', 'sha224',
-           'sha256', 'sha512', 'fi_business_id', 'fi_ssn', 'iban', 'ipv4',
-           'ipv4_cidr', 'ipv6', 'ipv6_cidr', 'length', 'mac_address', 'slug',
-           'truthy', 'url', 'ValidationFailure', 'validator', 'uuid',
-           'card_number', 'visa', 'mastercard', 'amex', 'unionpay', 'diners',
-           'jcb', 'discover', 'btc_address')
+__all__ = (
+    'between',
+    'domain',
+    'email',
+    'Max',
+    'Min',
+    'md5',
+    'sha1',
+    'sha224',
+    'sha256',
+    'sha512',
+    'fi_business_id',
+    'fi_ssn',
+    'iban',
+    'ipv4',
+    'ipv4_cidr',
+    'ipv6',
+    'ipv6_cidr',
+    'length',
+    'mac_address',
+    'slug',
+    'truthy',
+    'url',
+    'ValidationFailure',
+    'validator',
+    'uuid',
+    'card_number',
+    'visa',
+    'mastercard',
+    'amex',
+    'unionpay',
+    'diners',
+    'jcb',
+    'discover',
+    'btc_address',
+)
 
 __version__ = '0.18.0'
diff --git a/validators/between.py b/validators/between.py
index 46f223c9..6d67c372 100644
--- a/validators/between.py
+++ b/validators/between.py
@@ -44,9 +44,7 @@ def between(value, min=None, max=None):
     .. versionadded:: 0.2
     """
     if min is None and max is None:
-        raise AssertionError(
-            'At least one of `min` or `max` must be specified.'
-        )
+        raise AssertionError('At least one of `min` or `max` must be specified.')
     if min is None:
         min = Min
     if max is None:
diff --git a/validators/card.py b/validators/card.py
index 8b8cbeea..c8eed55e 100644
--- a/validators/card.py
+++ b/validators/card.py
@@ -136,9 +136,7 @@ def diners(value):
     :param value: Diners Club card number string to validate
     """
     pattern = re.compile(r'^(30|36|38|39)')
-    return (
-        card_number(value) and len(value) in [14, 16] and pattern.match(value)
-    )
+    return card_number(value) and len(value) in [14, 16] and pattern.match(value)
 
 
 @validator