函数封装

"""两个数的和"""
def sum_2_num():

    num1 = 10
    num2 = 20
    result1 = num1 + num2

    print("%d + %d = %d" % (num1, num2, result1))

sum_2_num()

'++++++++++++++++++++++++++++++++++++++++++++++++++++'

def sum_2_num(num1, num2):

    result2 = num1 + num2
    print("%d + %d = %d" % (num1, num2, result2))

sum_2_num(10, 20)

'++++++++++++++++++++++++++++++++++++++++++++++++++++'

def sum_2_num(num1, num2):

    return num1 + num2

result3 = sum_2_num(10, 20)

print("计算结果是 %d" % result3)