函数参数传递方法

1.位置传递
def message(name, address):
return “my name is %s ,my home locate in %s.” %(name,address)
print(message(“lily”,”shanghai”))
调用 message，分别把lily，shanghai 传递给name，address

2.关键字传递
def message(name, ago, address):
return “my name is %s ,%s years ago,my home locate in %s.” %(name, ago, address)
关键字传递，可以无视参数顺序
print(message(name = “lily”, address = “shanghai”, ago = 12))
关键字和位置混用，位置参数要在关键字前面
print(message(“lily”, address = “shanghai”, ago = 12))

3.默认值参数
def message(name, ago, address=”shanghai”):
return “my name is %s ,%s years ago,my home locate in %s.” %(name, ago, address)
address 该参数没有给传递值，参数赋予默认值
print(message(name=”lily”, ago=12))
第二次调用函数的时候，address被赋值为beijing，不再使用默认值。
print(message(name=”lily”, address=”beijing”, ago=12))

4.包裹传递
参数被all收集，type： tuple
def message(*all):
print(all)
print(type(all))
message(“a”,”b”,”c”)

参数被collect收集，type： dict
def age(**collect):
print(collect)
print(type(collect))
age(lily=12, xiaoming=13, sare=14)

结果：
(“a”, “b”, “c”)
<class “tuple”>
{“lily”: 12, “xiaoming”: 13, “sare”: 14}
<class “dict”>

包裹传递的关键在于定义函数时，在相应元组或字典前加*或**

5.解包
tuple1 = [1, 4, 6]
dict1 = {“a”: “test1”, “b”: “test2”, “c”: “test3”}
print(“dict1”, dict1)
def use(a, b, c):
print(a, b, c)
use(**dict1) # 把字典参数解包 此时相当于关键字参数传递 名字和函数定义的参数名必须要一一对应
use(*tuple1) #把元组解包 此时相当于位置参数传递
结果：
dict1 {“a”: “test1”, “b”: “test2”, “c”: “test3”}
test1 test2 test3
1 4 6