A Simple Python Decorator Function to Print the Runtime of a Function

timer_decorator.py

# -*- encoding: utf-8 -*-

__author__       = "Debmalya Pramanik"

__status__       = "production"
__version__      = "1.0"
__docformat__    = "camelCasing"

__copyright__    = "Copyright (c) 2020 Debmalya Pramanik | Indian Institute of Technology (IIT), Dhanbad"
__affiliation__  = "Reliance Industries Ltd."

import time
import functools

def timeit(func):
    """Inspired from `timeit` this Decorator Calculates the Execution time of a Function
    
    Usage - Use as a Decorator `@timeit` as follows:
    
    ```python
    @timeit
    def some_function():
        # do some work
    
    some_function() # execute the function with the decorator
    > Run time for some_function: ****
    ```
    """
    
    @functools.wraps(func)
    def _wrapper(*args, **kwargs): # accepts all arguments
        start = time.time()
        _return = func(*args, **kwargs) # execute the actual function
        
        end = time.time() # function executed, time is calculated with ms precision
        
        # calculate execution time is seconds (if t > 0), else in ms
        _exce_time = f"{(end - start):0.2f} s" if int(end - start) > 0 else f"{(end - start)*1e3:0.2f} ms"
        print(f"Run time for {func.__name__}: {_exce_time}")
        return _return
    
    return _wrapper