A Dive Into Automated Testing In Python With Pytest

Introduction

Automated testing is an essential aspect of software development that allows us to evaluate the effectiveness and correctness of our code. Among the various tools used for testing in Python, PyTest stands out for its simplicity and rich feature set. This blog post will give a brief overview of getting started with PyTest for automated testing in Python.

What is PyTest?

PyTest is a testing framework based on python that allows you to write simple, easily readable tests. It is known for its ease of use and ability to handle complex functionality testing.

Setting up PyTest

To begin using PyTest, you first need to install it. This can be done via pip.

pip install -U pytest

Structure of a PyTest Function

In PyTest, each test is written as a function. Here is a simple test that checks if the function add() correctly adds two numbers.

def add(x, y):
    return x + y

def test_add():
    assert add(2, 3) == 5

Running a Test

To run the tests, you simply execute pytest followed by the name of the python file that contains the tests in your terminal.

pytest test_file.py

Mini Project: Testing a Simple Web Scraper

Now let us apply our knowledge to test a simple web scraper. Below is a rudimentary Python function that uses the requests and BeautifulSoup libraries to scrape the title of a webpage.

from bs4 import BeautifulSoup
import requests

def get_title(url):
    response = requests.get(url)
    soup = BeautifulSoup(response.text, 'html.parser')
    return soup.title.string

We can then write a simple PyTest function to test the get_title() function:

def test_get_title():
    url = "https://www.google.com"
    expected = "Google"
    assert get_title(url) == expected

Running the test using pytest test_web_scraper.py should yield a successful result, provided the title of the Google homepage does not change.

In conclusion, PyTest offers an efficient and straightforward approach to automated testing in Python. It simplifies the process of setting and running tests, providing comprehensive testing solutions for both simple and complex applications. Automated testing is not only a best practice in software development, but it also empowers you to write robust, error-free code.