Python full stack development from getting started to giving up function basics

1, why to use the function
#1. Avoid code reuse
#2. Improve the readability of your code

2. Definition of function
def function name (parameter 1, parameter 2):
"' Function comment '
Print ("function body")
Return "returned value"

3. Function call
return value = function name (parameter 1, parameter 2)

4, function definition--return value
#关键字: Return
#return的作用:
#1. Ending the execution of a function
#2. Returns the value to return
#返回值的两种情况:
#返回值为None
#返回值不为None
#1. Returns a value
#2. Returning Multiple values

5. Function call--Receive return value
#返回值为None do not receive
#返回值不为None
# 1. Return a value
#用一个变量接收
# 2. Return multiple values
#用一个变量接收, the received result is a tuple
#有多少个返回值就用多少个变量接收

#参数--standing on the point of defining the function
#1. Position parameters,
#2. Default parameters
#3. Dynamic Parameters
#*args
#**kwargs
#顺序 positional parameter *args default parameter **kwargs

#参数--standing on the point of calling the function
#1. Pass the parameter by location
#2. by keyword
#3. Dynamic parameter *tup **dic

1. The first return value can be any data type

1 def func (): 2     a = 1113     b = [1,2,3]4     return b5 6 ret = func ()   

2. function can not return value

1 def func1 (): 2     A = 1113     b = [4]ret = func1 ()print (ret)6  # function can have no return value 7# when no return is written, the default return value of a function is ' None '

3.

1 def Func2 (): 2     A = 1113     b = [5]4     return#  ret = FUNC2 ()  6#  print (ret)7# When you write only one return, the return value of the function is None
None

4.

def func3 ():     = 111    = [+=    ]return  None#  ret = func3 ()# thereturn value of the function is none (almost unused) when print (ret)#return is None

5.

Python full stack development from getting started to giving up function basics