to import just part of a modulr

[snippsat]

Can use from my_module import d
my_module.py:

a = 100
b = 200
c = 300
d = 400

bar.py:

from my_module import d

print(d)

Output:
400

So now have access to only d in bar.py.
A module is always fully imported,so doing import my_module and from my_module import d make no difference in bottom.
So sys.modules['my_module'] has reference to whole file.

>>> import sys
>>> sys.modules['my_module']
<module 'my_module' from 'E:\\div_code\\new\\my_module.py'> 

from my_module import d point straight to d.
But whether you use anything else from the module or not,it's always fully imported.

import my_module binds the name my_module to sys.modules['my_module'].
Then can access all other names from it.

>>> import my_module

>>> my_module.a
100
>>> my_module.b
200
>>> my_module.d
400