What is the difference between global and nonlocal variables in Python?

What is the difference between global and nonlocal variables in Python?

In Python, a global variable is defined outside of any function and can be accessed anywhere in the code. A nonlocal variable, on the other hand, is defined in a nested function and allows you to modify a variable from an enclosing scope.

Can you give me an example of how to use nonlocal variables?

Sure! Here's an example:

x = 10

def outer_function():
    nonlocal x
    x = 20
    print("Inside outer_function:", x)

outer_function()
print("Outside function:", x)

This will output:

Inside outer_function: 20
Outside function: 20

What happens if I try to modify a global variable inside a function?

If you try to modify a global variable inside a function without declaring it as global, Python will treat it as a local variable. You need to use the global keyword to modify it.

Can you show me an example of that?

Certainly! Here's an example:

x = 5

def modify_global():
    global x
    x = 10

modify_global()
print(x)  # This will print 10