pip-lock

Check for differences between requirements.txt files and the current environment.

Installation

Install with python -m pip install pip-lock.

Python 3.6 to 3.9 supported.

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Example usage

Call pip_lock.check_requirements() at your application startup to verify that the current virtual environment matches your requirements file. This gives instant feedback to developers changing branches etc. who would otherwise experience unexpected behaviour or errors due to out of sync requirements.

In a Django project, it makes sense to add the check inside the manage.py file, which is the project’s main entrypoint. You can add a call to pip_lock.check_requirements() after the first import of Django. For example:

#!/usr/bin/env python
import os
import sys
from pathlib import Path


def main():
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "example.settings")

    try:
        from django.core.management import execute_from_command_line
    except ImportError as exc:
        raise ImportError(
            "Couldn't import Django. Are you sure it's installed and "
            "available on your PYTHONPATH environment variable? Did you "
            "forget to activate a virtual environment?"
        ) from exc

    try:
        import pip_lock
    except ImportError:
        raise ImportError(
            "Couldn't import pip-lock. Are you on the right virtualenv and up "
            + "to date?"
        )

    requirements_path = str(Path(__file__).parent / "requirements.txt")
    pip_lock.check_requirements(
        requirements_path,
        post_text="\nRun the following:\n\npython -m pip install -r requirements.txt\n",
    )

    execute_from_command_line(sys.argv)


if __name__ == "__main__":
    main()

API

check_requirements(requirements_file_path: str, post_text: str='') -> None

Exit with exit code 1 and output to stderr if there are mismatches between the environment and requirements file.

requirements_file_path is the path to the requirements.txt file - we recommend using an absolute file path.

post_text is optional text which is displayed after the stderr message. This can be used to display instructions on how to update the requirements.

Example:

check_requirements(
    "requirements.txt",
    post_text="\nRun the following on your host machine: \n\n    vagrant provision\n",
)

There are requirement mismatches with requirements.txt:
    * Package Django has version 1.9.10 but you have version 1.9.0 installed.
    * Package requests has version 2.11.1 but you have version 2.11.0 installed.
    * Package requests-oauthlib is in requirements.txt but not in virtualenv

Run the following on your host machine:

    vagrant provision

get_mismatches(requirements_file_path: str) -> dict[str, tuple[str, str | None]]

Return a dictionary of package names to tuples of (expected_version, actual_version) for mismatched packages.

requirements_file_path is the path to the requirements.txt file - we recommend using an absolute file path.

Example:

>>> get_mismatches("requirements.txt")
{'django': ('1.10.2', '1.9.0'), 'requests': ('2.11.1', '2.9.2'), 'request-oauthlib': ('0.7.0', None)}