Python如何传递任意数量的实参

传递任意数量的实参

形参前加一个 * ，Python会创建一个已形参为名的空元组，将所有收到的值都放到这个元组中：

defmake_pizza(*toppings):
print("\nMakingapizzawiththefollowingtoppings:")
fortoppingintoppings:
print("-"+topping)
make_pizza('pepperoni')
make_pizza('mushroom','greenpeppers','extracheese')

不管函数收到多少实参，这种语法都管用。

1. 结合使用位置实参和任意数量实参

defmake_pizza(size,*toppings):
print("\nMakinga"+str(size)+"-inchpizzawiththefollowingtoppings:")
fortoppingintoppings:
print("-"+topping)
make_pizza(16,'pepperoni')
make_pizza(12,'mushroom','greenpeppers','extracheese')

运行结果：

Makinga16-inchpizzawiththefollowingtoppings:
-pepperoni
Makinga12-inchpizzawiththefollowingtoppings:
-mushroom
-greenpeppers
-extracheese

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2. 使用任意数量的关键字实参

defbuild_profile(first,last,**user_info):
profile=dict()
profile['first_name']=first
profile['last_name']=last
forkey,valueinuser_info.items():
profile[key]=value
returnprofile
user_profile=build_profile('albert','einstein',location='princeton',field='physic')
print(user_profile)

形参**user_info中的两个星号让python创建了一个名为user_info的空字典。