《笨办法学Python》习题21：函数可以返回东西

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

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

age = add(30, 5)
height = subtract(78, 4)
weight = multiply(90, 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."

what = add(age, subtract(height, multiply(weight, divide(iq, 2))))

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