Calculator Python – Loop – Addition – Subtraction

#this variable tells the loop whether it should loop or not.
# 1 means loop. anything else means don't loop.

loop = 1

#this variable holds the user's choice in the menu:

choice = 0

while loop == 1:
#print what options you have
print "Welcome to calculator.py"

print "your options are:"
print " "
print "1) Addition"
print "2) Subtraction"

print "3) Multiplication"

print "4) Division"
print "5) Quit calculator.py"
print " "

choice = input("Choose your option: ")
if choice == 1:
add1 = input("Add this: ")
add2 = input("to this: ")
print add1, "+", add2, "=", add1 + add2
elif choice == 2:
sub2 = input("Subtract this: ")
sub1 = input("from this: ")
print sub1, "-", sub2, "=", sub1 - sub2
elif choice == 3:
mul1 = input("Multiply this: ")
mul2 = input("with this: ")
print mul1, "*", mul2, "=", mul1 * mul2
elif choice == 4:
div1 = input("Divide this: ")
div2 = input("by this: ")
print div1, "/", div2, "=", div1 / div2
elif choice == 5:
loop = 0