What is the role of scope in the Python language and how does it affect access to variables?

Scope in Python defines where a variable is accessible for reading and writing. It affects how the interpreter searches for a variable when it is referenced.

The main types of scope are:

• Local — variables declared inside a function, accessible only within it.
• Enclosing — the scope of an outer function, if the function is nested inside another.
• Global — variables declared at the module level.
• Built-in — names defined in Python's standard library.

When referencing a variable, Python searches in the order LEGB (Local, Enclosing, Global, Built-in).

Example:

a = 10  # global variable

def outer():
    b = 20  # outer variable
    def inner():
        c = 30  # local variable
        print(a, b, c)
    inner()

outer()

To modify a global variable inside a function, use the global keyword:

count = 0

def increment():
    global count
    count += 1

Scope helps avoid name conflicts and manage variable lifetimes.