What is lexical scoping in Python?

What is lexical scoping in Python?

Lexical scoping refers to the visibility of variables in nested functions. In Python, a function can access variables from its own scope, the enclosing scope, and the global scope.

Can you give me an example of lexical scoping?

Sure! Here's a simple example:

def outer_function():
    x = 'outer'
    
def inner_function():
        y = 'inner'
        print(x)  # This will print 'outer'
    inner_function()

In this case, inner_function can access the variable x from outer_function.

What happens if I try to access a variable from a different function?

If you try to access a variable from a different function that is not in the enclosing scope, you'll get a NameError. For example, trying to access y from outer_function will fail because y is not defined there.

How does this differ from dynamic scoping?

In dynamic scoping, the variable's value is determined by the call stack at runtime, rather than the structure of the code. Python uses lexical scoping, which means the scope is determined by the physical structure of the code.