1. Local variables
name = "Yang Li"
def change_name(name):
print("before change:",name)
name = "Hello."
print("after change", name)
change_name(name)
print("Look outside to see if NAME has changed?",name)
Output:
before change: Yang Li
After change. - Hello.
Check outside to see if name has changed? Yang Li
2、Global variables
NAME = "alex"
def yangjian():
global NAME # It's already declared, NAME is the global variable
print('1 my name', NAME)
NAME = "land" # Modify global variables
print('2 My Name', NAME)
def qupengfei():
name = "yang"
print('3 My Name', NAME)
yangjian()
qupengfei()
Output:
1My name. alex 2My name. land 3My name. yang ######## global variable variable name uppercase ######## Lowercase local variable variable names #in a function Priority reading of local variables，Can read global variables，Unable to reassign values to global variables；But for variable types，Internal elements can be manipulated；如果in a function有globalKeywords.，A variable is essentially the global one，Readable and assignable
3、nonlocal
name = "Gunnar."
def weihou():
name = "Chancho."
def weiweihou():
nonlocal name # nonlocal, specifies a higher level variable, if there is none then continue up until you find it
name = "Calm down."
print(name)
weiweihou()
print(name)
print(name)
weihou()
print(name)
# Gunnar
# Chen Zhuo
# Chen Zhuo
# father's elder brother's wife
Global and Local Variables
Variables defined in a subroutine are called local variables, and variables defined at the beginning of a program are called global variables.
The global variable scope is the entire program, and the local variable scope is the subroutine in which the variable is defined.
When a global variable has the same name as a local variable:
Local variables act within the subroutine in which they are defined; global variables act elsewhere.
Function Return Value
To get the result of a function's execution, you can return the result with the return statement
Caution.
Whenever a function encounters a return statement during execution, it stops execution and returns the result, so it can also be interpreted that the return statement represents the end of the function.
If return is not specified in the function, the return value of the function is None.
nested function
name = "Alex"
def change_name():
name = "Alex2"
def change_name2():
name = "Alex3"
print("Layer 3 printing",name)
change_name2() # Calling inner functions
print("Layer 2 printing",name)
change_name()
print("Outermost printing",name)
This is the whole content of this article.