What is the difference between closures and lexical scoping in Python?

What is the difference between closures and lexical scoping in Python?

Closures are functions that capture the lexical scope in which they were defined, allowing them to remember variables from that scope even when called outside of it. Lexical scoping, on the other hand, refers to the visibility of variables based on their location within the source code.

Can you give me an example of a closure in Python?

Sure! Here's a simple example:

def outer_function(x):
    def inner_function(y):
        return x + y
    return inner_function

closure = outer_function(10)
print(closure(5))  # Output: 15

In this example, inner_function is a closure that remembers the value of x from outer_function.

How does lexical scoping work in Python?

In Python, lexical scoping means that a variable's scope is determined by its position in the source code. For example, a variable defined inside a function is not accessible outside of it, but it can be accessed by nested functions.

Are there any performance implications of using closures?

Yes, using closures can have performance implications, especially if they capture a large number of variables or if they are used in a tight loop. This can lead to increased memory usage and slower execution times.