The definition of a function call, the return value
1. The role of function: a package to reduce duplication of code
2. The format of the function
def keyword defines a function
def function name ():
Indent function body (block)
def func():
print('我')
print('爱')
print('你')
return '1314' #返回值,将内容返回给调用者
#不写return或写了return不写值返回None
msg = func() #函数名() -- 调用
print(msg)a plurality of variable return returns, returns the ancestral form, what is returned is not limited
When performing the function to return the time is over, return the following code does not execute, and terminate the function.
return can not terminate the loop, only the termination function
Parameter Two function
2.1 positional parameters
def func(addr,addr1): #形参
print(f'我在{addr}上网')
print(f'你在{addr1}睡觉')
func('网吧','沙发') #实参 Parameter is defined parameters, parameters of the call is the argument, the argument from the process parameter called mass parameter
Parameter is a variable name, the argument is the value that is assigned mass participation
And the number of formal parameters correspond to arguments
2.2 Keyword parameters (argument angle)
def func(addr1,addr):
print(f'我在{addr}上网')
print(f'你在{addr1}睡觉')
func(addr = '网吧',addr1 = '沙发')2.3 mixing parameters
def func(addr,addr1):
print(f'我在{addr}上网')
print(f'你在{addr1}睡觉')
func('网吧',addr1 = '沙发')Note: when using the mixing parameters, keyword parameters must be in the back position parameters
2.4 The default value of the parameter (parameter angle)
def func(addr,addr1= '沙发'): #默认值参数
print(f'我在{addr}上网')
print(f'你在{addr1}睡觉')
func('网吧',addr1 = '床上') #下面的addr1的值会覆盖上面的值NOTE: When using the mixing parameters, the default value of the parameter must be behind the position parameters
Most of the default values for the parameters passed in the general parameters are the same
2.5 dynamic parameters
1. Dynamic Universal position parameter variable name * (any number of receiving) position parameters
def eat(a,b,*args,c='白菜'): #聚合打包
print('我想吃',a,b,args,c) #元祖形式(接受的是位置参数)
eat('猪肉','粉条','豆腐','大葱')Results:
I want to eat pork vermicelli ( 'tofu', 'onion') cabbage
def eat(a,b,*args,c='白菜'):
print('我想吃',a,b,*args,c) #打散
eat('猪肉','粉条','豆腐','大葱')Results:
I want to eat pork, cabbage, green onions tofu noodles
Dynamic parameter must be behind the position parameters
Order parameter: the parameter position, the position of the dynamic parameters, the default parameters
2. Dynamic keyword arguments variable name **
def func(**kwargs):
print(kwargs) # 字典形式(接收的是关键字参数)
func(a=1, b=2, c=3)result:
{'a': 1, 'b': 2, 'c': 3}
def func(**kwargs):
print(*kwargs) # 得到的是字典的键
func(a=1, b=2, c=3)result:
a b c
def func(a,b,*args,c=1,**kwargs):
print(a,b,c,args,kwargs)
func(1,2,3,4,5,6,7,8,9,c=55,d=1,f=3)result:
1 2 55 (3, 4, 5, 6, 7, 8, 9) {'d': 1, 'f': 3}
Position parameter> * args (dynamic position parameter)> The default value of the parameter> ** kwargs (dynamic default parameters)
Transfer list
lst = [1,4,7]
def func(*args):
print(args)
func(*lst) #打散 去壳
#在实参的位置上用*将lst(可迭代对象)按照顺序打散在#形参的位置上用*把收到的参数组合成一个元祖Biography Dictionary
dic = {'a':1,'b':2}
def func(**kwargs)
print(kwargs)
func(**dic) #字典的键必须是字符串Note 3 to function
In the function "" "Enter" ""
函数名.__doc__ 查看函数的注释