What is difference between ">=" and "~=" when use in python "requirements.txt" for some library version?

Question

What is the difference between >= and ~= when use in python requirements.txt for some library? For example requests >= 2.18.0 and requests ~= 2.18.0

I have tried both the things and its working fine

requests >= 2.18.0
requests ~= 2.18.0

Could anyone please explain me the exact difference between the >= and ~= operator?

Answer 1

To install greater than or equal to one version and less than another (ordered comparisons):

pip install 'SomeProject>=1,<2'

To install a version that’s compatible with a certain version (compatible releases):

pip install 'SomeProject~=1.4.2'

Both format specifiers are documented in PEP 440 – Version Identification and Dependency Specification.