python study notes, video day15- global variables and local variables, rheumatism theory, recursive function

Recalling the last lesson

1. Function　　

　　　In mathematical function: y = 2 * x + 1

　　　python parameters:

　　　　def test（x,y,type=None）:

　　　　　　"Notes"

　　　　　　Block

　　　　　　return res

　　　　Function name represents the memory address references, to add parentheses when calling

2. Parameters

　　--- total memory parameter when you call, do not release memory when calling

Arguments - total memory

One to one positional parameters

Keyword arguments

The default parameters

Positional parameters in keyword arguments left

　　　def test（x,*args,**kwargs）:

　　　　　　"Notes"

　　　　　　Block

　　　　　　return res

4. Functions benefits:

　　Reduce duplication of code

　　Easy to maintain

　　Scalable

Global variables and local variables

Global variables: There is no indentation, which entered into force in the global variable
Local variables: variables defined in the subroutine
Only functions have privacy function
Interpreter running from top to bottom, the compiler does not perform functions that encounter only

　　　　Rules: global variable variable name in uppercase, lowercase variable names of local variables it

global global variables, variables on a nonlocal

= name " . Yangzi " # global variable 
DEF Change_Name (): 
    name = " jinmi " local variable # 
    Print ( " chang_name " , name) 
Change_Name () 
Print (name)
 # Results 
# chang_name jinmi 
# . Yangzi

　global

　　If the content of the function of the non-global keyword

　　Priority read local variables, no local variables can be read global variables, global variables can not be assigned to; may operate for a variable number of internal elements variables

　　There declare local variables

name="yangzi"
def change_name():
    name="jinmi"
    print("chang_name",name)
change_name()
# 结果
# chang_name jinmi

　　No declaration of local variables

name="yangzi"
def change_name():
    print("chang_name",name)
change_name()
# 结果
# chang_name yangzi

name=["yangzi","jingtian"]
def change_name():
    name.append("123")
    print("chang_name",name)
change_name()
# 结果
# chang_name yangzi

　　There are global keyword, the variable is essentially a global variable can be assigned reading　

name=["产品经理","qianyue"]
def change_name():
    global name
    name="jinmi"
    print("chang_name",name)
change_name()
print(name)
# 结果
# chang_name jinmi
# jinmi

NAME  ="海峰"
def name1():
    name="huang"
    print(name)
    def liuyang():
        name="liuyang"
        print(name)
        def mulige():
            name="huzhihua"
            print(name)
        print(name)
        mulige()
    liuyang()
    print(name)

name1()
# 结果
# huang
# liuyang
#Liuyang 
# huzhihua 
# huang

#global global variable 
name = " Yangzi " 
DEF weihou (): 
    name = " chenzhuo " 
    DEF weiweihou ():
         , Ltd. Free Join name 
        name = " lengjin " 
    weiweihou () 
    Print (name)
 Print (name) 
weihou () 
Print (name) 

# results 
# Yangzi 
# chenzhuo 
# lengjin

# nonlocal上一级变量
name ="yangzi"
def weihou():
    name="chenzhuo"
    def weiweihou():
        nonlocal name
        name="lengjin"
    weiweihou()
    print(name)
print(name)
weihou()
print(name)

# 结果
# yangzi
# lengjin
# yangzi

Rheumatism theory

No function watch 05 python s3 day15 rheumatoid Theory i.e. variable .ev4

Recursive function

Internal calls the function