Global Variable in Python

Question

I am very new to Python. Not learnt classes yet. Using Python 3.2.2. Tried implement some procedural C logic. My code is spread over 2 files as follows.

this file i

Answer 1

To assign values to a global variable in your code you've got to mark it as such, otherwise the code would be assigning to a local variable with the same name (that would be actually shadowing the global variable).

As explained in the documentation:

It would be impossible to assign to a global variable without global, although free variables may refer to globals without being declared global.

Hence, to fix the problem, you'd need something like this:

def isValidDate(d,m,y):
    if(d>=1 and d<=31 and m>=1 and m<=12):
        global dd, mm, yy
        dd,mm,yy=d,m,y
        ...