Python: Importing pandas into main and modules?

I have a python script with a structure that looks like the following:

/
  __init__.py
  main.py
  /modules
    fbm.py

I am attempting to split some functions out from main.py into fbm.py and then import fbm.py as a module using.

sys.path.extend([f'{item[0]}' for item in os.walk("./app/modules/") if os.path.isdir(item[0])])
import fbm

This is working.

What I am having trouble with is where I need to call pandas (or another import) from a module.
I'm currently importing pandas in main.py with import pandas as pd.
When I call the function from fbm an error is thrown as soon as it hits a reference to pd stating that NameError: name 'pd' is not defined. pd is defined in main.py, but not fbm.py. It thus works in main, but not in fbm.

So, my question is: Is it good and appropriate to import pandas as pd in both the main.py and each module which requires pandas?

• Will this have an impact on memory usage, ie loading multiple copies of pandas
• is there a better way to handle this?

It is appropriate to import pandas (or any other library) in both the main script and each module that requires it. This is a common practice and ensures that each module can function independently, which makes the code more modular and easier to maintain.

Regarding your concerns about memory usage: Python is smart enough to handle imports efficiently. When a module is imported for the first time, it's loaded and cached in the sys.modules dictionary. So, if the same module is imported again (even with a different alias), Python will use the cached module instead of loading it again and again. So, there won't be any significant impact on memory usage.