Python Testing with pytest

Exercises

Testing scripts can be quite fun. Running through the process on a second script will help you remember the techniques in this chapter.

The exercises start with an example script, sums.py, that adds up numbers in a separate file, data.txt.

Here’s sums.py:

exercises/ch12/sums.py

# sums.py
# add the numbers in `data.txt`

sum = 0.0

with open("data.txt", "r") as file:
    for line in file:
        number = float(line)
        sum += number

print(f"{sum:.2f}")

And here’s an example data file:

exercises/ch12/data.txt

123.45
 76.55

If we run it, we should get 200.00:

$ cd /path/to/code/exercises/ch12
$ python sums.py data.txt
200.00

Assuming valid numbers in data.txt, we need to test this script.

1. Write ...