How Can I Use a Variable From One Function in Another - python-3.x

Question

I'm trying to write a code where there are a bunch of if statements in each function. I want to be able to use a variable from a previous function and then add that variable into another function.
Here is an example:
def main():
name = input('What is your name?')
age = int(input('What is your age?'))
number = int(input('What is your favourite number?'))
if number > 0:
print('Your favourite number is %d and it is positive.' % (number))
elif number < 0:
print('Your favourite number is %d and it is negative.' % (number))
else:
print('Your favourite number is %d and it is equal to 0.' % (number))
subtract()
def subtract():
salary = float(input('Enter your monthly salary.'))
expenses = float(input('Enter your monthly expenses'))
result = (salary - expenses)
if result < 0:
print('Save more!')
else:
print('Congratulations on saving!')
def final():
percentage = result / a
finalpercent = percentage * 100
if finalpercent == 0:
print('No money!!')
elif finalpercent < 50:
print('Getting there...')
else:
print('You have lots of money!!')
main()
What I want is to use the result variable from def subtract(): function in the def final(): function?

Answer 1

Make the result variable from the subtract function the return value of that function.
Something like this:
def main():
name = input('What is your name?')
age = int(input('What is your age?'))
number = int(input('What is your favourite number?'))
if number > 0:
print('Your favourite number is %d and it is positive.' % (number))
elif number < 0:
print('Your favourite number is %d and it is negative.' % (number))
else:
print('Your favourite number is %d and it is equal to 0.' % (number))
final(subtract()) # RESULT IS RETURNED BY SUBTRACT AND THEN USED BY FINAL AS PARAMETER
def subtract():
salary = float(input('Enter your monthly salary.'))
expenses = float(input('Enter your monthly expenses'))
result = (salary - expenses)
if result < 0:
print('Save more!')
else:
print('Congratulations on saving!')
return result
def final(result):
percentage = result / a
finalpercent = percentage * 100
if finalpercent == 0:
print('No money!!')
elif finalpercent < 50:
print('Getting there...')
else:
print('You have lots of money!!')
main()
Also the variable a is not defined in the final function, that will cause an error, so check that too :).

Answer 2

Use Global variable. Creating a Global variable means you could access that variable from any function or class.
def main():
name = input('What is your name? ')
age = int(input('What is your age? '))
number = int(input('What is your favourite number? '))
if number > 0:
print('Your favourite number is %d and it is positive.' % (number))
elif number < 0:
print('Your favourite number is %d and it is negative. ' % (number))
else:
print('Your favourite number is Zero.')
subtract()
def subtract():
global salary # Declaring salary as Global Variable
salary = float(input('Enter your monthly salary: '))
expenses = float(input('Enter your monthly expenses: '))
global result # Declaring result as Global Variable
result = (salary - expenses)
if result < 0:
print('Save more!')
else:
print('Congratulations on saving!')
final()
def final():
percentage = result / salary
finalpercent = percentage * 100
if finalpercent == 0:
print('No money!!')
elif finalpercent < 50:
print('Getting there...')
else:
print('You have lots of money!!')
main()
I convert those local variable salary and result using global keyword. so that I could use that two variables outside of that function.
Another Approach is to pass that variable as an argument by calling final function. Like this...
def main():
name = input('What is your name? ')
age = int(input('What is your age? '))
number = int(input('What is your favourite number? '))
if number > 0:
print('Your favourite number is %d and it is positive.' % (number))
elif number < 0:
print('Your favourite number is %d and it is negative. ' % (number))
else:
print('Your favourite number is Zero.')
subtract()
def subtract():
salary = float(input('Enter your monthly salary: '))
expenses = float(input('Enter your monthly expenses: '))
result = (salary - expenses)
if result < 0:
print('Save more!')
else:
print('Congratulations on saving!')
final(result, salary) # calling final function by passing it as argument
def final(result, salary):
percentage = result / salary
finalpercent = percentage * 100
if finalpercent == 0:
print('No money!!')
elif finalpercent < 50:
print('Getting there...')
else:
print('You have lots of money!!')
main()