using self-developed modules

[wlp]

Thx for your suggestions.
T
First some more info: some time ago I have installed Python 3.7.4 and all the “packages” that I need using the standard installation (“Install Now” without customizing folder names). I selected the “Install Launcher” and “Add PATH” as recommended.

I have tried, as you suggested, with “solution 3”, but it definitely looks as if my Python does not “follow the book”.
I have documented both modules with some more comments here”)

# main.py
#
# is stored in G:\\UserData\\actname\\Documents\\Programmas\\Python_3-7-4\\
#
import sys
from selfwrittenmodule import f1, f2
def if1(x):
    a = f1(x);return(a)
def if2(x):
    a = f2(x);return(a)

b = 2
a = if1(b)
c = if2(b)
print (a, c)

# selfwrittenmodule.py
#
# is stored in C:\\Users\\actname\\AppData\\Local\\Programs\\Python\\Python37-32\\Lib\\generaluse\\
#
def f1(x):
    x = x + 1
def f2(x)
    x = x + 10

When I “edit” main with IdleX and press F5 (run), then I receive this error msg:

Error:
Traceback (most recent call last):
 File "G:\UserData\actname\Documents\Programs\Python_3-7-4\main.py", line 6, in <module>
    from selfwrittenmodule import f1, f2
ModuleNotFoundError: No module named 'selfwrittenmodule'

Then I renamed the foldername from C:\\Users\\actname\\AppData\\Local\\Programs\\Python\\Python37-32\\Lib\\generaluse\\ to C:\\Users\\actname\\AppData\\Local\\Programs\\Python\\Python37-32\\Lib\\selfwrittenmodule\\, and executed “main” again with IdleX. Then I get this error message:

Error:
Traceback (most recent call last):
 File "G:\UserData\actname\Documents\Programs\Python_3-7-4\main.py", line 6, in <module>
    from selfwrittenmodule import f1, f2
ImportError: cannot import name 'f1' from 'selfwrittenmodule' (unknown location)
>>>

Please tell me what I did wrong.