Python Testing with pytest

Testing an Importable Python Script

We can change our script code a tiny bit to make it importable and allow tests and code to be in different directories. We’ll start by making sure all of the logic in the script is inside a function. Let’s move the workload of hello.py into a main() function:

ch12/script_importable/hello.py

def main():
    print("Hello, World!")


if __name__ == "__main__":
    main()

We call main() inside a if __name__ == ’__main__’ block. The main() code will be called when we call the script with python hello.py:

$ cd /path/to/code/ch12/script_importable
$ python hello.py
Hello, World!

The main() code won’t be called with just an import. We have to call main() explicitly:

$ python