Prevent Python packages from re-exporting imported names

There is no easy way to forbid importing a global name from a module; Python simply is not built that way.

While you could possibly achieve the forbidding goal if you wrote your own __import__ function and shadowed the built-in one, but I doubt the cost in time and testing would be worth it nor completely effective.

What you can do is import the dependent modules with a leading underscore, which is a standard Python idiom for communicating “implementation detail, use at your own risk“:

import re as _re
import sys as _sys

def hello():
    pass

Note

While just deleting the imported modules as a way of not allowing them to be imported seems like it might work, it actually does not:

import re
import sys

def hello():
    sys
    print('hello')

del re
del sys

and then importing and using hello:

>>> import del_mod
>>> del_mod.hello()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "del_mod.py", line 5, in hello
    sys
NameError: global name 'sys' is not defined