从概念上理解，print是打印输出，return是返回值。区别如下：
1、return是结束语一般放在函数的最后，当函数执行return 得到返回值后，后面的语句就不执行了。

------------------------------
def additive(x,y):
    z = x + y
    print("hello world!")
    return z
    print("I love Python!")
additive(1,1)
-------------------------------
hello world!
2

2、return返回的结果可以被调用。

------------------------------
def additive(x,y):
    z = x + y
    print("I love Python!")
    return z
    print("I can't print!")
------------------------------
print (additive(1,1))
x= (additive(1,1))+10
print (x)
------------------------------
I love Python!
2
I love Python!
12

3、print仅仅只是打印，没有结果

------------------------------
def additive(x,y):
    z = x + y
    print(z)
------------------------------
print (additive(1,1))
x= (additive(1,1))+10
print (x)
------------------------------
2
None
2

TypeError                                 Traceback (most recent call last)
<ipython-input-16-1f9bcb00fbf9> in <module>()
      1 print (additive(1,1))
----> 2 x= (additive(1,1))+10
      3 print (x)

TypeError: unsupported operand type(s) for +: 'NoneType' and 'int'