Check version of Python library that doesn't define __version__

Question

I'm dealing with a Python library that does not define the __version__ variable (sqlalchemy-migrate), and I want to have different behavior in my code based on what version of the library I have installed.

Is there a way to check at runtime what version of the library is installed (other than, say, checking the output of pip freeze)?

Answer 1

This being Python, the accepted way of doing this is generally to call something in the library that behaves differently depending on the version you have installed, something like:

import somelibrary
try:
    somelibrary.this_only_exists_in_11()
    SOME_LIBRARY_VERSION = 1.1
except AttributeError:
    SOME_LIBRARY_VERSION = 1.0

A more elegant way might be to create wrapper functions.

def call_11_feature():
    try:
        somelibrary.this_only_exists_in_11()
    except AttributeError:
        somelibrary.some_convoluted_methods()
        somelibrary.which_mimic()
        somelibrary.the_11_feature()