Python References global variables

1.global is called a keyword in python, not a command

The role of 2.global is to refer to global variables to local scopes

3. If there is not a variable A in the global variable and a statement such as Globa A is written in the function, then a variable a is created in the global variable

4. code example:

########################################################################

a=10

def fun ():

Global A

A = 20

Fun ()

Print (a)

Summary: A general example of referencing global variables in a function, that is, a local scope

#########################################################################

def fun ():

Global A

A = 20

Fun ()

Print (a)

Summary: This code because there is no global variable A, and the function refers to the variable A, the subsequent execution of the SUM function, so print out the global variable A

############################################################################

"Key Notes"

When will the global general be used? This is useful when you want to change global variables in a local scope.

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a=10

def fun ():

Global A

A = 20

A=a+30

Fun ()

Print (a)

Summary: This code will end up typing 40, because in the local scope has changed the global variable a value, the global variable in a is not the previous 10, now is the modified 40

Python References global variables