Program failing after converting global variables/ to local

[coolindienc]

I converted this program from using global variables to local variables. When I did that my while loop stopped working in my main function(module ). Anyone, any idea why? I underlined the area where I think the problem occured after my changes.

Old Code working FINE

from math import *
 
def menu():
    global menuSel
    print "\nSlect one of the following:"
    print "1. Calculate Area of Rectangle"
    print "2. Calculate Area of Circle"
    print "3. Quit"
    menuSel=input("Please enter your selection: ")
    while menuSel!=1 and menuSel!=2 and menuSel!=3:
        menuSel=input("Please re-enter a valid selection of 1, 2, or 3: ")
    return
 
def rectangle():
    print "You have chosen a rectangle."
    b=input("enter base  : ")
    h=input("enter height:")
    print "The area is ", b*h
    return
 
def circle():
    print "You have chosen a circle."
    r=input("enter radius: ")
    print "The area is ",pi*r**2
    return
 
 
def main():
    menu()
    while menuSel!=3:
        if menuSel==1:
            rectangle()
        elif menuSel==2:
            circle()
        menu()
    return
 
main()
raw_input("\nPress enter to exit.")
 

New Code NOT working

from math import *
 
 def menu():
    print "\nSlect one of the following:"
    print "1. Calculate Area of Rectangle"
    print "2. Calculate Area of Circle"
    print "3. Quit"
    menuSel=input("Please enter your selection: ")
    while menuSel!=1 and menuSel!=2 and menuSel!=3:
        menuSel=input("Please re-enter a valid selection of 1, 2, or 3: ")
    return
 
def rectangle():
    print "You have chosen a rectangle."
    b=input("enter base  : ")
    h=input("enter height:")
    print "The area is ", b*h
    return
 
def circle():
    print "You have chosen a circle."
    r=input("enter radius: ")
    print "The area is ",pi*r**2
    return
 
 
 def main():
    choice = menu()
    while choice!=3:
        if choice==1:
            rectangle()
        elif choice==2:
            circle()
        choice =menu()
    return
 
main()
raw_input("\nPress enter to exit.")
 

[bartonc]

You have to return the value from you functions. ie:

def menu():
    print "\nSlect one of the following:"
    print "1. Calculate Area of Rectangle"
    print "2. Calculate Area of Circle"
    print "3. Quit"
    menuSel=input("Please enter your selection: ")
    while menuSel!=1 and menuSel!=2 and menuSel!=3:
        menuSel=input("Please re-enter a valid selection of 1, 2, or 3: ")
    return menuSel

In fact, if you don't need value returned (some languages call this a "procedure" ), there is no need to put the return at the end. Such functions (and the way you wrote them) return None. Return can also be used to jump out of a fuction at any point. ie:

if time_to_exit:
    return