The document explains the concept of variable scope in Python, detailing how variables can be defined globally or locally and how their usage differs based on their definitions. It covers key terms such as global keywords, non-local descriptors, and the LEGB rule, which outlines the hierarchy of namespaces in Python. Additionally, it discusses how non-local variables function in nested scopes and the significance of closures.

2. If you know Python or any other programming language,
you probably know that the variables must be defined
before they can be used in your program. The variable
must be used in different ways depending on how and
where it is determined. Some of the variables are defined
globally, others locally. This means that a variable
referring to a specific part of the program may refer to
another part of the program.

3.  Define a Python function variable inside or outside
 global keywords
 non-local descriptor
 Closed Python
 LEGB in the rules

4. Define a Python function variable inside or outside
If you specify a variable at the top of the script, it is a
global variable. This means that it can be used for any of
the manuals, including in a function. See the following
example, where a is defined globally.

5. The keyword world
Overall, it tells Python to use a globally defined variable
instead, which will be determined locally. If you want to
use it, just write in the global and the name of the
variable. In this case, the name of the global variable can
now change the name of the change () is used.

6. non-local descriptor
The nonlocal expression is useful for nested operations.
This makes the variable refer to the variable previously
limited to the variable closest to the fence. In other
words, you avoid the variable to try to link the first to
the local level and force it to reach the "higher" level.

7. Closed Python
You close the function objects that store the values of
the closed areas, even if they are no longer in memory.
LEGB in the rules
As we have seen in the past, namespaces can be
independent of one another and have certain levels of
the hierarchy, referenced in their scope.

8. Depending on where you are in the program, they are used in
different namespaces. You can specify the order in which
Python uses the name, you can use LEGB in the rules.
LEGB means:
local
attached
global
integrated

9. some of this conclusion may have grown a bit narrow. In
deference, I’ve removed all the “postscript” updates that
appeared here in prior editions. This edition retains the
conclusion itself, though, partly because of its historical
value (python online training)

10. https://www.besanttechnologies.com