timeit is a Python module used to time small parts of your Python script. You can call timeit from the command line as well as import the timeit module into your script. We are going to write a script to time a piece of code. Create a timeit_example.py script and write the following content into it:

import timeit
prg_setup = "from math import sqrt"
prg_code = '''
def timeit_example():
            list1 = []
            for x in range(50):
                        list1.append(sqrt(x))
'''
# timeit statement
print(timeit.timeit(setup = prg_setup, stmt = prg_code, number = 10000))

Using timeit, we can decide what piece of code we want to measure the performance of. So, we can easily define the setup code as well as the code snippet on which we want to perform the test separately. The main code runs 1 million times, which is the default time, whereas the setup code runs only once.