Could you explain what parameter passing in functions means?

Passing parameters to a function is a way to provide input data to the function for processing. In Python, parameters are passed by object reference, but the behavior depends on the mutability of the object.

• For mutable objects (e.g., lists, dictionaries), changes inside the function affect the original object.
• For immutable objects (e.g., numbers, strings, tuples), a local copy is created inside the function, and the original object remains unchanged.

Example:

def add_element(lst):
    lst.append(4)  # modify the original list

my_list = [1, 2, 3]
add_element(my_list)
print(my_list)  # Outputs: [1, 2, 3, 4]


def increment(n):
    n += 1  # local change

num = 5
increment(num)
print(num)  # Outputs: 5

Thus, parameters allow a function to work with external data, modify it, or use it for calculations.