How do you determine the speed of a program?

Using the timeit module for precise measurement of execution time of small code snippets or functions.

import timeit

def my_function():
    # Your code to measure
    pass

# Measuring execution time of my_function
execution_time = timeit.timeit(stmt=my_function, number=1000) # Run 1000 times and measure total time
print(f"Execution time: {execution_time} seconds")

You can also use the time module for simpler measurements.

import time

start_time = time.time() # Start measurement

# Your code to measure
time.sleep(1) # Example work

end_time = time.time() # End measurement
print(f"Execution time: {end_time - start_time} seconds")

For profiling and identifying bottlenecks in more complex programs, modules cProfile and profile are used.

import cProfile

def slow_function():
    for _ in range(100000):
        pass

cProfile.run('slow_function()') # Profile the function call

Another way is to use a decorator to measure function execution time.

import time

def timer_decorator(func):
    def wrapper(*args, **kwargs):
        start_time = time.time()
        result = func(*args, **kwargs)
        end_time = time.time()
        print(f"Function '{func.__name__}' executed in {end_time - start_time:.4f} seconds")
        return result
    return wrapper

@timer_decorator
def fast_function():
    time.sleep(0.1)

fast_function()