Scope of global and nonlocal in Python

Python refers to the order of variables: the current scope local variable, the outer scope variable, and the global variable->python built-in variables in the current module.
Global
First, in the local if you declare a global variable, you can modify the global variable, otherwise no
Gcount = 0
Def global_test ():
Global Gcount
Gcount+=1
Print (Gcount)
Global_test ()
Correct output 1
————————————————————————————
Gcount = 0
Def global_test ():
Gcount+=1
Print (Gcount)
Global_test ()
Unboundlocalerror:local variable ' gcount ' referenced before assignment
If you want to modify a global variable within a function, you need to use the keyword global
Second, if the global variable is not declared locally, and the global variable is not modified. You can use global variables normally:

Scope of global and nonlocal in Python