Issue with importing specific functions from modules

Question

I have two separate modules that I am trying to import specific functions into each other however I keep getting an import error on the functions that are defined within the helperModule.py module itself. What am I doing wrong?

helperModule.py

from utilsModule import startProcess
def getCfgStr():
 pass
def getCfgBool():
 pass
def doSomethingElse():
 startProcess()

utilsModule.py

from helperModule import getCfgStr, getCfgBool
def startProcess():
 a = getCfgStr()
 b = getCfgBool()
 pass

• Two-Bit Alchemist: You have a circular import. A cannot import from B which imports from A. You need to refactor.
• DSM: I'm confused. I thought the problem was a circular import error, but you claim your first file is called helperModule.py but your second imports from a module called utilshelperModule. So is this a case of a circular import error being hidden by a typo, or did you misreport the name of your files? (Since you only described the error instead of copy-pasting the actual error, it's hard to distinguish between the two.)
• Two-Bit Alchemist: @DSM Same (hence "seems to correspond" in my answer) but I went ahead and answered anyway. I guess if it turns out I'm wrong I'll get the deserved downvotes to show for it.
• ILostMySpoon: @DSM Sorry, copy and paste error!
• ILostMySpoon: @Two-BitAlchemist Fixed!

Answer 1

You show:

from utilsModule import startProcess

which corresponds to your utilsModule.py where the startProcess function is defined. At the top of that file, you show:

from helperModule import getCfgStr, getCfgBool

which corresponds to your helperModule.py where these two functions are defined.

This is a circular import. utilsModule imports from utilshelperModule which imports from utilsModule... you see where I'm going.

You must refactor and have them both import from a third file to prevent this.

Answer 2

You could either have the functions need the functions they need (on runtime instead of on load time):

def getCfgStr():
 pass
def getCfgBool():
 pass
def doSomethingElse():
 from utilsModule import startProcess
 startProcess()
def startProcess():
 from helperModule import getCfgStr, getCfgBool
 a = getCfgStr()
 b = getCfgBool()

Or you at least could do the imports as late as possible:

def getCfgStr():
 pass
def getCfgBool():
 pass
def doSomethingElse():
 startProcess()
from utilsModule import startProcess

and

def startProcess():
 a = getCfgStr()
 b = getCfgBool()
from helperModule import getCfgStr, getCfgBool

Here, we first put the functions into existence and then provide their global name space with the functions from the other module.

This way, a circular import will probably work, because the imports happen late.

It will nevertheless work, as long as none of the functions affected is used at import time.