Why do I get a "referenced before assignment" error when assigning to a global variable in a function?

In Python, I'm getting the following error:

UnboundLocalError: local variable 'total' referenced before assignment 

At the start of the file (before the function where the error comes from), I declare total using the global keyword. Then, in the body of the program, before the function that uses total is called, I assign it to 0. I've tried setting it to 0 in various places (including the top of the file, just after it is declared), but I can't get it to work.

Does anyone see what I'm doing wrong?

4 Answers

I think you are using 'global' incorrectly. See Python reference. You should declare variable without global and then inside the function when you want to access global variable you declare it global yourvar.

#!/usr/bin/python total def checkTotal(): global total total = 0 

See this example:

#!/usr/bin/env python total = 0 def doA(): # not accessing global total total = 10 def doB(): global total total = total + 1 def checkTotal(): # global total - not required as global is required # only for assignment - thanks for comment Greg print total def main(): doA() doB() checkTotal() if __name__ == '__main__': main() 

Because doA() does not modify the global total the output is 1 not 11.

My Scenario

def example(): cl = [0, 1] def inner(): #cl = [1, 2] # access this way will throw `reference before assignment` cl[0] = 1 cl[1] = 2 # these won't inner() 

def inside(): global var var = 'info' inside() print(var) >>>'info' 

problem ended

I want to mention that you can do like this for the function scope

def main() self.x = 0 def increment(): self.x += 1 for i in range(5): increment() print(self.x)