I’m trying to conditionally call a function based on the availability of a module, and that availability is not known until runtime.

The code does not work and I’ve reduced my issue down to the following minimum reproducible testcase where a module imported within a function is visible in sys.modules but is otherwise not actually fully available. What is going on? (And how can I fix it?)

#!/usr/bin/env python3
import sys

# python --version - Python 3.10.12


def import_re():
    import re
    if 're' in sys.modules:
            print("Yes, it is there 1")

import_re()
if 're' in sys.modules:
        print("Yes, it is there 2")
re.match('a', 'a')



'''
Output:

Yes, it is there 1
Yes, it is there 2
Traceback (most recent call last):
  File "/tmp/test2.py", line 13, in <module>
    re.match('a', 'a')
NameError: name 're' is not defined
'''