Pytest is a framework for testing Python code. Due to easy use, well-written documentation, and open-source It’s the most widely-used Python testing framework. To use Pytest you need to install it using pip. 

pip install -U pytest

Other frameworks for testing Python code:

• Robot - https://robotframework.org/
• Unittest - https://docs.python.org/3/library/unittest.html
• DocTest - https://docs.python.org/3/library/doctest.html
• Nose2 - https://docs.nose2.io/en/latest/

Pros

• Supports unittest.
• Open-source.
• Well-written documentation.
• Allows writing simple and compact test suits.
• Allows test parametrization.
• Test written using Pytest are extensible, there are many plugins available.
• Provides fixtures.
• Capable of executing multiple test cases simultaneously.
• Capable of skipping selected test methods from a group of methods during execution.
• Allows generating HTML test results.

Cons:

• Because of Pytest’s unique syntax, you won’t be able to use tests written in Pytest in the different frameworks.

Official Pytest documentation: https://docs.pytest.org/en/6.2.x/contents.html