Python variable name resolution LEGB principle

For a def statement:

The variable name is divided into three scopes to find: first local, then function, then global, and finally built-in

By default, a variable name assignment creates or alters a local variable

when an unauthenticated variable name is used in a function, Python searches for 4 scopes (local scope, followed by the local scope of def or lambda in the last layer of the construct, followed by the global scope, and finally built-in scopes,

However, when assigning a variable name to a function, Python always creates or alters the variable name of the local scope, unless it is declared as a global variable in that function.

When assigning a variable name outside of a function (that is, the top level of a module file), the local scope is the same as the global scope

Python variable name resolution LEGB principle