Python Scope: Beginner python tutorials 16 | Better4Code

Python scope refers to the visibility of variables within different parts of your code. Understanding the concept of scope is important when writing complex programs in Python. In this article, we’ll explain what Python’s scope is and provide examples to help you understand how it works.

What is Python Scope?
Python scope determines the visibility of variables in different parts of a program. When you create a variable, it’s assigned a scope based on where it’s defined. There are four types of scope in Python:

Local Scope: Variables defined within a function have local scope, which means they can only be accessed within that function.

Enclosing Scope: If a variable is defined within a nested function, it has enclosing scope, which means it can be accessed by any function nested inside the original function.

Global Scope: Variables defined outside of any function have global scope, which means they can be accessed from anywhere in the program.

Built-in Scope: This is the scope that contains all the built-in functions and modules provided by Python.

 

Examples of Python Scope
Here are some examples of Python scope in action:

Local Scope

def my_function():
    x = 10
    print(x)

my_function()
print(x)  # Error: x is not defined

In this example, the variable x is defined within the local scope of the function my_function(). This means it can only be accessed within the function. When we try to print the value of x outside the function, we get an error because x is not defined in the global scope.

 

Enclosing Scope

def outer_function():
    x = 10
    def inner_function():
        print(x)
    inner_function()

outer_function()

In this example, the variable x is defined within the outer_function(), which gives it enclosing scope. The inner_function() is nested within the outer_function() and can access the value of x because of the enclosing scope.

Global Scope

x = 10

def my_function():
    print(x)

my_function()
print(x)

In this example, the variable x is defined outside of any function, giving it global scope. This means it can be accessed from anywhere in the program, including within the function my_function().

 

Built-in Scope

import math

x = math.sqrt(16)
print(x)

In this example, we’re using the built-in module math to calculate the square root of 16. The functions and modules provided by Python are always available in the built-in scope.

 
Conclusion
In this article, we explained what Python’s scope is and provided examples to help you understand how it works. We looked at local, enclosing, global, and built-in scope, and how they affect the visibility of variables in different parts of a program. By understanding Python’s scope, you can write more effective and efficient code that takes advantage of the powerful scoping features of the language.