How to avoid circular import looping

Question

I am getting confused with importing in python. It seems that I have the problem of circular importing, but I am not sure how to fix this problem in the right way. An example:

file1:

value = 5

import file2
file2.set()

file2:

import file1

def set():
    file1.value = 6

Answer 1

You have a few options:

1. put all your code in one file, if it needs to be this tightly linked

value = 5

def set():
    value = 6

set()

2. put the code that uses parts from the others in a third file, or in other words break up your code so you avoid the circular references - your example is a bit too simple to make that work though.

3. pass values to functions you want to use, or pass objects you want to modify; importing and modifying another module's globals isn't a very good way to design your program anyway:

# this is my_module.py

def set_value(x):
    x.value = 6


def increment(x):
    return x + 1

And elsewhere:

import my_module


class X:
    value = 5


x = X()
my_module.set_value(x)

y = 5
y = my_module.increment(y)