#0070

Count Calls With a Decorator

MediumPython25 min20 XP

Problem

Implement count_calls so decorating a function adds a calls attribute that increments each time the function runs.

Why This Matters

Decorators power logging, timing, caching, retries, validation, and web framework routes.

Function Signature

def count_calls(func):

Examples

Example 1

Input@count_calls def add(a,b): return a+b; add(1,2); add(3,4)

Outputadd.calls == 2

The wrapper increments before delegating to the original function.

Constraints

Support positional and keyword arguments.
Expose a calls attribute on the returned function.
Return the original function result.

CodePython

def count_calls(func):
    """
    Input example: @count_calls def add(a,b): return a+b; add(1,2); add(3,4)
    Return: add.calls == 2
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return func

def count_calls(func):
    """
    Input example: @count_calls def add(a,b): return a+b; add(1,2); add(3,4)
    Return: add.calls == 2
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return func

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Counts repeated calls

Inputdecorated add function

Expectedcalls == 2

Each invocation should increment the counter.

Hidden Test Categories

zero calls initiallyfunction with no argumentsreturn value preserved