Only want one function to be imported yet the full program comes over

Question

I made 2 programs for show porpose. I would like to import the global variable from the transmitter function into another file, yet the problem that I encounter is that the While true loop also comes along spoiling my whole second program, because the second problem now also starts to show the itiration.

Program 1:

import time

def transmitter():
    global temp

global temp
temp = 2

transmitter()

while True: # a random task just to see if I only imported the function
    x = 0
    print(x + 1)
    time.sleep(0.2)

Program 2:

from transmitguy import transmitter

def valuepullup():
    newval = transmitguy.transmitter()
    print(newval)

valuepullup()

I only need my second program to show the value of 2 once. (2 is the globalvar from file 1)

Put everything but the function into [`if __name__ == "__main__":`](https://stackoverflow.com/q/419163/1639625) — tobias_k, Jul 14 '17 at 09:38
fixed the file, the original program was called openUSB, changed the name for upload — Anton van der Wel, Jul 14 '17 at 09:45
put it in the [if __name__ == "__main__":], it now gives the value none — Anton van der Wel, Jul 14 '17 at 09:49
Your function returns `None`, since you haven't written it to return anything else. It's a useless function, since it doesn't do anything at all. I'm not sure what you expect your `global` statements to do, but currently they're completely pointless. — Blckknght, Jul 14 '17 at 11:34

score 1 · Accepted Answer · answered Jul 14 '17 at 12:21

The short answer is that you can't get only one piece of a module. from x import y imports x in the same way import x does. The only difference is that, in the former case, y is added to your current global namespace, and in the latter case, x is. The docs for import say:

The from form ... find[s] the module specified in the from clause, loading and initializing it if necessary ...

I am not sure exactly what you are trying to accomplish. As the commenters noted, you can check for __main__. However, you might do better to put your variable in its own module, then import that module from both of your existing modules.

Only want one function to be imported yet the full program comes over

1 Answers1