代码如下：把第3行的加号换成了减号
1 def add(a, b): 2 print "ADDING %d + %d" % (a, b) 3 return a - b 4 def substract(a, b): 5 print "SUBTRACTING %d - %d" % (a, b) 6 return a - b 7 def multiply(a, b): 8 print "MULTIPLYING %d * %d" % (a, b) 9 return a * b 10 def divide(a, b): 11 print "DIVIDING %d / %d" % (a, b) 12 return a / b 13 14 age = add(30, 5) 15 height = substract(78, 4) 16 weight = multiply(90, 2) 17 iq = divide(100, 2) 18 19 print "Age: %d, Height: %d, Weight: %d, IQ:%d" % (age, height, weight, iq) 20 21 what = add(age, substract(height, multiply(weight, divide(iq, 2)))) 22 print "That becomes:", what, "Can you do it by hand?"
运行结果可见，return的值和定义变量里print那一行的内容无关
总觉得冗余的内容太多反而不利于理解，以下简化代码：
1 def add(a, b): 2 return a - b 3 def substract(a, b): 4 return a - b 5 def multiply(a, b): 6 return a * b 7 def divide(a, b): 8 return a / b 9 10 age = add(30, 5) 11 height = substract(78, 4) 12 weight = multiply(90, 2) 13 iq = divide(100, 2) 14 15 print "Age: %d, Height: %d, Weight: %d, IQ:%d" % (age, height, weight, iq) 16 17 what = add(age, substract(height, multiply(weight, divide(iq, 2)))) 18 print "That becomes:", what, "Can you do it by hand?"
输出结果：