Example Python Code for CISC320

readme.md

The first file below (basic_example.py) demonstrates a simple Python program that reads a filename from standard input and processes it. Specifically, the helper function prints all the lines and also returns the last line of the file.

The second file (student_test.py) demonstrates some very basic unit testing of the helper function.

basic_example.py

"""
Author: acbart@udel.edu
Updated: 2/4/2021
Description: A sample of taking a filename from stdin, loading it into a string
             array, and printing out the first line.
"""


def print_all_lines(lines: list[str]) -> str:
    """ Print each line, then return the last one. """
    latest_line = None
    for line in lines:
        # Readlines includes the newline character
        latest_line = line.strip()
        print(latest_line)
    return latest_line


if __name__ == "__main__":
    # Get the filename from stdin
    filename = input()

    # Open the file and read in its contents
    with open(filename) as data_file:
        lines = data_file.readlines()

    # Actually do the work
    print_all_lines(lines)

student_test.py

import unittest
import basic_example


class TestLast(unittest.TestCase):
    def test_gets_last(self):
        actual = basic_example.print_all_lines(["1\n", "2\n", "3\n"])
        self.assertEqual(actual, "3")

    def test_handles_empty(self):
        actual = basic_example.print_all_lines([])
        self.assertEqual(actual, None)

if __name__ == '__main__':
    unittest.main()