global name is not defined error

Question

My code:

import sys
import time
import random


def main():
    print('***TEST**** Grad School Multiplier=',gradschoolmultiplier,'***TEST***')
    x=gradschoolmultiplier*50000
    print('Your salary in dollars, $',x)

def start():    
    gradschool=input('Do you intend to go to Graduate School? ')
    print('')
    time.sleep(2)
    if gradschool=='yes':print('That is a fantastic if expensive decision.')
    elif gradschool=='Yes':print('That is a fantastic if expensive decision.')
    elif gradschool=='Y':print('That is a fantastic if expensive decision.')
    elif gradschool=='y':print('That is a fantastic if expensive decision.')
    elif gradschool=='YES':print('That is a fantastic if expensive decision.')
    else:print('No?  Well, then it\'s off to work to pay back those student loans.')
    print('')
    if gradschool=='yes':g1=3
    elif gradschool=='Yes':g1=3
    elif gradschool=='Y':g1=3
    elif gradschool=='y':g1=3
    elif gradschool=='YES':g1=3
    else:g1=1
    g=random.randrange(1, 3)
    if g==1:gradschoolmultiplier=1
    else:gradschoolmultiplier=g1*g/2
    time.sleep(2)
    main()

start()

And of course I get:

NameError: global name 'gradschoolmultiplier' is not defined

I am not smart enough to understand the answers to this question for others. Would someone be so kind as to explain the answer in simpletons' terms? Thanks!

Answer 1

Indeed as @Dan says, the scoping problem.

Or you can use global variables.

Some of my other suggestions on your code:

import sys
import time
import random


def print_salary():
    print('***TEST**** Grad School Multiplier=',gradschoolmultiplier,'***TEST***')
    x = gradschoolmultiplier*50000
    print('Your salary in dollars, $',x)

def main():    
    gradschool=input('Do you intend to go to Graduate School? ')
    print('')
    time.sleep(2)

    if gradschool.lower() in {'yes', 'y'}:
        print('That is a fantastic if expensive decision.')
        g1 = 3
    else:
        print('No?  Well, then it\'s off to work to pay back those student loans.')
        g1 = 1
    print('')

    g = random.randrange(1, 3)
    global gradschoolmultiplier
    if g == 1:
        gradschoolmultiplier = 1
    else:
        gradschoolmultiplier = g1 * g / 2
    time.sleep(2)
    print_salary()

if __name__ == '__main__':
    main()

You should combine some the if statements to make it simpler.

Oh, we share the same thoughts @jonrsharpe

Quick improvement as suggested by @Nils

Answer 2

gradschoolmultiplier is not in the scope of main(), it only exists in start().

You can pass it into main.

change the call to main to be main(gradschoolmultiplier)

change def main() to def main(gradschoolmultiplier):

Information on python scoping