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A flake8 extension that checks for exact pins (e.q.: `foo==1.5.6`) in

Project Description

Check for exact pins (==) of package requirements in install_requires in

For example:

    # ...
    # ...

Exact pins are often a bad idea, as they:

  • Limit flexibility if your package is going to be reused; i.e.: used as a library by other Python libraries or applications. You are forcing them to use a particular version that they may not want to use or that conflicts with what they already use. Not so much of an issue if your package is an application rather than a library; however, often requirements.txt is a better place to manage application requirements that you are pinning (see
  • Bake a very strict requirement into your package; you may have to rebuild your package just to use a new version of a package with a bug fix.
  • Create the potential for hard-to-resolve version conflicts, if you exact pin some package versions and don’t exact pin others. Some of your other packages may require a different version than the one you’re pinning and it might be impossible for pip to resolve this.


If you don’t already have it, install flake8:

$ pip install flake8

Then, install the extension:

$ pip install flake8-exact-pins


Run the following to verify that the plugin has been installed correctly:

$ flake8 --version
2.4.1 (pep8: 1.5.7, flake8-exact-pin: 0.0.0, pyflakes: 0.8.1, mccabe: 0.3) CPython 2.7.9 on Darwin

Now, when you run flake8, the plugin will automatically be used.

When an exact pin is found, flake8 will output something like:

./ P001 exact pin found in install_requires: "pyramid==1.5.6"
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File Name & Checksum SHA256 Checksum Help Version File Type Upload Date
flake8_exact_pin-0.0.1-py2-none-any.whl (5.2 kB) Copy SHA256 Checksum SHA256 2.7 Wheel Jun 25, 2015
flake8-exact-pin-0.0.1.tar.gz (3.0 kB) Copy SHA256 Checksum SHA256 Source Jun 25, 2015

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