Question

If I have a module/file foo.py with the following contents:

from math import sqrt

def foo():
    pass

If I import it in another script, sqrt is also defined within the module foo.

import foo    
dir(foo)

The output of which is

[..., # other things
 'foo',
 'sqrt']

How do I prevent this? i.e., either specify sqrt not to be exported, or export only specific functions – in this case, only the user-defined ones. I know for user-defined functions you can define them privately within the module by prefixing with an underscore, but in this case it’s not a user-defined function so I can’t define it with an underscore prefix.

Answer 1

in this case it’s not a user-defined function so I can’t define it with an underscore prefix.

Yes, you can:

from math import sqrt as _sqrt

An alternative is to only import objects in function scopes, where you need them.

(While this may answer your question, I still have no idea why you’d want to do it. Both options are cumbersome and won’t make your codebase look any better.)