ex21.py

#!/bin/python2
# -*- coding: utf-8 -*-

# ex21: Functions Can Return Something


def add(a, b):
    print "ADDING %d + %d" % (a, b)
    return a + b


def subtract(a, b):
    print "SUBTRACTING %d - %d" % (a, b)
    return a - b


def multiply(a, b):
    print "MULTIPLYING %d * %d" % (a, b)
    return a * b


def divide(a, b):
    print "DIVIDING %d / %d" % (a, b)
    return a / b


# my function to test return
def isequal(a, b):
    print "Is %r equal to %r? - " % (a, b) ,
    return (a == b)


print "Let's do some math with just functions!"

age = add(30, 5)
height = subtract(78, 4)
weight = multiply(92, 2)
iq = divide(100, 2)

print "Age: %d, Height: %d, Weight: %d, IQ: %d" % (age, height, weight, iq)


# A puzzle for the extra credit, type it in anyway.
print "Here is a puzzle."

# switch the order of multiply and divide
what = add(age, subtract(height, divide(weight, multiply(iq, 2))))

print "That becomes: ", what, "Can you do it by hand?"

# test the return value of isequal()
num1 = 40
num2 = 50
num3 = 50

print isequal(num1, num2)
print isequal(num2, num3)


# A new puzzle.
print "Here is a new puzzle."

# write a simple formula and use the function again
uplen = 50
downlen = 100
height = 80
what_again = divide(multiply(height, add(uplen, downlen)), 2)

print "That become: ", what_again, "Bazinga!"