Local and Global Variables

tags: #python/documentation/python_functions

Understand the Scope of Variables

The scope of the variables refers to where variables can be referenced. A variable created within a function is referred to as a local variable, whereas a variable created outside of a function is referred to as a global variable and are accessible by all parts of the code.

Summary Table

	Local Variables	Non-Local Variables	Global
Definition	Variables declared within a function	Used in nested functions. Need to be explicitly declared `nonlocal` to be access references from an outer function.	Variables declared outside of a function, or explicitly declared as `global` within a function.
Scope	Can only accessed from within a function. Cannot be referenced from outside the function.	Accessible and modifiable by nested functions.	Accessible and modifiable from any part of the code (inside and outside of a function).
Lifetime	Only exists while the function is being executed. When the function terminates (returns a value), the local variables are destroyed.	Same as local variables.