Skip to main content

flake8 plugin which checks for misuse of `sys.version` or `sys.version_info`

Project description

Build Status Azure DevOps coverage

flake8-2020

flake8 plugin which checks for misuse of sys.version or sys.version_info

this will become a problem when python3.10 or python4.0 exists (presumably during the year 2020).

you might also find an early build of python3.10 useful

installation

pip install flake8-2020

flake8 codes

Code Description
YTT101 sys.version[:...] referenced (python3.10)
YTT102 sys.version[2] referenced (python3.10)
YTT103 sys.version compared to string (python3.10)
YTT201 sys.version_info[0] == 3 referenced (python4)
YTT202 six.PY3 referenced (python4)
YTT203 sys.version_info[1] compared to integer (python4)
YTT204 sys.version_info.minor compared to integer (python4)
YTT301 sys.version[0] referenced (python10)
YTT302 sys.version compared to string (python10)

rationale

lots of code incorrectly references the sys.version and sys.version_info members. in particular, this will cause some issues when the version of python after python3.9 is released. my current recommendation is 3.10 since I believe it breaks less code, here's a few patterns that will cause issues:

# in python3.10 this will report as '3.1' (should be '3.10')
python_version = sys.version[:3]  # YTT101
# in python3.10 this will report as '1' (should be '10')
py_minor = sys.version[2]
# in python3.10 this will be False (which goes against developer intention)
sys.version >= '3.5'  # YTT103


# correct way to do this
python_version = '{}.{}'.format(*sys.version_info)
py_minor = str(sys.version_info[1])
sys.version_info >= (3, 5)
# in python4 this will report as `False` (and suddenly run python2 code!)
is_py3 = sys.version_info[0] == 3  # YTT201

# in python4 this will report as `False` (six violates YTT201!)
if six.PY3:  # YTT202
    print('python3!')

if sys.version_info[0] >= 3 and sys.version_info[1] >= 5:  # YTT203
    print('py35+')

if sys.version_info.major >= 3 and sys.version_info.minor >= 6:  # YTT204
    print('py36+')

# correct way to do this
is_py3 = sys.version_info >= (3,)

if not six.PY2:
    print('python3!')

if sys.version_info >= (3, 5):
    print('py35+')

if sys.version_info >= (3, 6):
    print('py36+')
# in python10 this will report as '1'
python_major_version = sys.version[0]  # YTT301
# in python10 this will be False
if sys.version >= '3':  # YTT302
    print('python3!')

# correct way to do this
python_major_version = str(sys.version_info[0])

if sys.version_info >= (3,):
    print('python3!')

as a pre-commit hook

See pre-commit for instructions

Sample .pre-commit-config.yaml:

-   repo: https://gitlab.com/pycqa/flake8
    rev: 3.7.8
    hooks:
    -   id: flake8
        additional_dependencies: [flake8-2020==1.2.0]

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

flake8_2020-1.2.0.tar.gz (4.4 kB view hashes)

Uploaded Source

Built Distribution

flake8_2020-1.2.0-py2.py3-none-any.whl (4.8 kB view hashes)

Uploaded Python 2 Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page