Compatible Release clause in Pip Requirements

TIL this exists.

https://www.python.org/dev/peps/pep-0440/#compatible-release

A compatible release clause consists of the compatible release operator ~= and a version identifier. It matches any candidate version that is expected to be compatible with the specified version.

In essense, this “tilda equals” operator means: “I’m telling you a version, but feel free to bump the last number as high as what is available”.

So

Django~=2.1

is equivelent to

Django >= 2.1, == 2.*

It won’t ever install Django 3, but it will go anywhere from 2.1 up.

If you define ~=2.1.1, it will go up to 2.1.*.

For me, I only found this by change, but the entire PEP440 has a whole bunch of useful features.

Being someone used to Ruby’s pessimistic version constraints (the “tilda greater than” meaning “start here and work your way up”), knowing this exists in Python is delightful.