Python Scope & the LEGB Rule: Resolving Names in Your Code

scope

In python The scope of variables depends on the place of the variable in your code where you create that variable. the scope of a name defines the area of a program in which you can access that name Python scope reduces bugs related to name collision

Scopes Types :

Global scope: The names that you define in this scope are available to all your code. For example assign a value to a name outside of all functions .

Local scope: The names that you define in this scope are only available or visible to the code within the scope . For example, assign a value to a name inside a function

in scope : the names that you can access out of scope : the names that you can’t access

How to access out of scope name :

• Using the dot notation on the module’s name in the form module.name
• Using a subscription operation on .__dict__ in the form module.__dict__['name']

LEGB rule ( Local, Enclosing, Global, and Built-in) : The LEGB rule is of name lookup procedure, which determines the order in which Python looks up names , and you can have fore scopes maximum , and at least two active scopes, which are the global and built-in scopes .

You can define a new local variable using the same name of global variable but you will not be able to access global variable anymore .

The good practice in programming that using local names rather than global names , we use global names as constants that don’t change during your program’s execution .

To delete the custom name from python all scopes use : del name It will remove the name from all scopes levels except the builtins names