Refueling

Refueling

This Python program is an implementation to CS50’s Introduction to Programming with Python Week 5 - Refueling Problem Set. The fuel.py program calculates the fuel gauge reading based on a given fraction input and provides the corresponding gauge reading using the convert and gauge functions. The convert function calculates the percentage representation of the given fraction, and the gauge function provides the corresponding gauge reading.

How to Run the Tests

1. Open your terminal.

2. Navigate to the directory where you have saved both fuel.py and test_fuel.py.

   cd path/to/your/directory
   

3. Run the tests using the pytest command:

   pytest test_fuel.py
   

4. The tests will be executed, and the results will be displayed in the terminal.

Program Code

fuel.py

def main():
    while True:
        try:
            fuel = gauge(convert(input("Fraction: ")))
            print(fuel)
            break
        except (ValueError, ZeroDivisionError):
            print("Invalid fraction.")


def convert(fraction):
    X, Y = fraction.split("/")
    if not X.isdigit() or not Y.isdigit():
        raise ValueError
    if int(Y) == 0:
        raise ZeroDivisionError
    if int(X) > int(Y):
        raise ValueError
    return round(100 * int(X) / int(Y))


def gauge(percentage):
    if percentage <= 1:
        return "E"
    elif percentage >= 99:
        return "F"
    else:
        return f"{percentage}%"


if __name__ == "__main__":
    main()

test_fuel.py

from fuel import convert, gauge
import pytest

def test_convert():
    assert convert("0/4") == 0
    assert convert("1/4") == 25
    assert convert("2/4") == 50
    assert convert("3/4") == 75
    assert convert("4/4") == 100
    with pytest.raises(ZeroDivisionError):
        convert('100/0')
    with pytest.raises(ValueError):
        convert('a/b')
    with pytest.raises(ValueError):
        convert('5/2')


def test_guage():
    assert gauge(25) == "25%"
    assert gauge(75) == "75%"
    assert gauge(100) == "F"
    assert gauge(99) == "F"
    assert gauge(0) == "E"
    assert gauge(1) == "E"

How to Test

1. Run the tests as mentioned in the "How to Run the Tests" section.
2. The tests will be executed, and you will see the results in the terminal.

Sample Test Cases

1. Conversion Test ("1/4"):

   • Input:

     assert convert("1/4") == 25
     

2. Gauge Reading Test (25%):

   • Input:

     assert gauge(25) == "25%"
     

     assert gauge(100) == "F"
     

     assert gauge(0) == "E"
     

3. Zero Division Error Test:

   • Input:

     with pytest.raises(ZeroDivisionError):
         convert('100/0')
     

4. Value Error Test (Non-Digit Input):

   • Input:

     with pytest.raises(ValueError):
         convert('a/b')
     

5. Value Error Test (X > Y):

   • Input:

     with pytest.raises(ValueError):
         convert('5/2')
     

Additional Notes

• Ensure that the fuel.py and test_fuel.py files are saved in the same directory and have the correct names.
• The tests in test_fuel.py cover various scenarios to validate the correctness of the convert and gauge functions. Running the tests using pytest will indicate whether your implementation of these functions is working correctly.