Hi, Pythonistas!
I’m working on an exercise for fun (not for school) but I’d still prefer to receive hints from you people instead of the full answer.
The task titled “Guido’s Gorgeous Lasagna” involves defining the expected bake time for a lasagna in minutes, calculating the remaining bake time in minutes, calculating the preparation time in minutes, and finally calculating the total elapsed cooking time (prep + bake) in minutes. We’re working with integers, not floats or decimals. The full exercise and task is described on exercism.org in the link above.
There is a unit test included and I’ve passed 4 of 5 assertions. So I am almost there.
Here is my code:
EXPECTED_BAKE_TIME = 40
PREPARATION_TIME = 30
def bake_time_remaining(elapsed_bake_time):
"""Calculate the bake time remaining.
:param elapsed_bake_time: int baking time already elapsed.
:return: int remaining bake time derived from 'EXPECTED_BAKE_TIME'.
Function that takes the actual minutes the lasagna has been in the oven as
an argument and returns how many minutes the lasagna still needs to bake
based on the `EXPECTED_BAKE_TIME`.
"""
return EXPECTED_BAKE_TIME - elapsed_bake_time
def preparation_time_in_minutes(number_of_layers):
"""
Empty Doc String
"""
return number_of_layers * 2
def elapsed_time_in_minutes(number_of_layers, elapsed_bake_time):
"""
Empty Doc String
"""
return preparation_time_in_minutes(elapsed_bake_time) - bake_time_remaining(number_of_layers)
Here is the final line in the traceback when I run my pytest:
FAILED lasagna_test.py::LasagnaTest::test_elapsed_time_in_minutes - AssertionError: -33 != 5 : Expected 3 minutes elapsed, but the timing was calculated incorrectly.
That is the biggest puzzle to me. I have no idea what that line is trying to convey. Is it suggesting that when -33 is passed into the last function as the first argument and 3 is passed in as the second argument, the function should (is expecting) a return of 5 but instead the those parameters return something else? I am way off base here. Could someone kindly clarify further?
Here is the assertion traceback in greater detail:
============================== FAILURES =======================
__________ LasagnaTest.test_elapsed_time_in_minutes _____________________
self = <lasagna_test.LasagnaTest testMethod=test_elapsed_time_in_minutes>
@pytest.mark.task(taskno=4)
def test_elapsed_time_in_minutes(self):
layer_data = (1, 2, 5, 8, 11, 15)
time_data = (3, 7, 8, 4, 15, 20)
result_data = [prep * 2 + elapsed for prep, elapsed in zip(layer_data, time_data)]
for variant, (layers, time, total_time) in enumerate(zip(layer_data, time_data, result_data), start=1):
with self.subTest(f'variation #{variant}', layers=layers, time=time, total_time=total_time):
failure_msg = f'Expected {time} minutes elapsed, but the timing was calculated incorrectly.'
> self.assertEqual(elapsed_time_in_minutes(layers, time), total_time, msg=failure_msg)
E AssertionError: -33 != 5 : Expected 3 minutes elapsed, but the timing was calculated incorrectly.
lasagna_test.py:63: AssertionError
For what it is worth, here is the complete unit test:
import unittest
import pytest
try:
from lasagna import (EXPECTED_BAKE_TIME,
bake_time_remaining,
preparation_time_in_minutes,
elapsed_time_in_minutes)
except ImportError as import_fail:
message = import_fail.args[0].split('(', maxsplit=1)
item_name = import_fail.args[0].split()[3]
if 'EXPECTED_BAKE_TIME' in message:
# pylint: disable=raise-missing-from
raise ImportError(f'We can not find or import the constant {item_name} in your'
" 'lasagna.py' file. Did you mis-name or forget to define it?")
else:
item_name = item_name[:-1] + "()'"
# pylint: disable=raise-missing-from
raise ImportError("In your 'lasagna.py' file, we can not find or import the"
f' function named {item_name}. Did you mis-name or forget to define it?')
class LasagnaTest(unittest.TestCase):
@pytest.mark.task(taskno=1)
def test_EXPECTED_BAKE_TIME(self):
failure_msg = 'Expected a constant of EXPECTED_BAKE_TIME with a value of 40.'
self.assertEqual(EXPECTED_BAKE_TIME, 40, msg=failure_msg)
@pytest.mark.task(taskno=2)
def test_bake_time_remaining(self):
input_data = [1, 2, 5, 10, 15, 23, 33, 39]
result_data = [40 - item for item in input_data]
for variant, (time, result) in enumerate(zip(input_data, result_data), start=1):
with self.subTest(f'variation #{variant}', time=time, result=result):
failure_msg = f'Expected: {result} but the bake time remaining was calculated incorrectly.'
self.assertEqual(bake_time_remaining(time), result, msg=failure_msg)
@pytest.mark.task(taskno=3)
def test_preparation_time_in_minutes(self):
input_data = [1, 2, 5, 8, 11, 15]
result_data = [item * 2 for item in input_data]
for variant, (layers, time) in enumerate(zip(input_data, result_data), start=1):
with self.subTest(f'variation #{variant}', layers=layers, time=time):
failure_msg = f'Expected: {time} minutes, but preparation time was calculated incorrectly.'
self.assertEqual(preparation_time_in_minutes(layers), time, msg=failure_msg)
@pytest.mark.task(taskno=4)
def test_elapsed_time_in_minutes(self):
layer_data = (1, 2, 5, 8, 11, 15)
time_data = (3, 7, 8, 4, 15, 20)
result_data = [prep * 2 + elapsed for prep, elapsed in zip(layer_data, time_data)]
for variant, (layers, time, total_time) in enumerate(zip(layer_data, time_data, result_data), start=1):
with self.subTest(f'variation #{variant}', layers=layers, time=time, total_time=total_time):
failure_msg = f'Expected {time} minutes elapsed, but the timing was calculated incorrectly.'
self.assertEqual(elapsed_time_in_minutes(layers, time), total_time, msg=failure_msg)
@pytest.mark.task(taskno=5)
def test_docstrings_were_written(self):
functions = [bake_time_remaining, preparation_time_in_minutes, elapsed_time_in_minutes]
for variant, function in enumerate(functions, start=1):
with self.subTest(f'variation #{variant}', function=function):
failure_msg = f'Expected a docstring for `{function.__name__}`, but received `None` instead.'
self.assertIsNotNone(function.__doc__, msg=failure_msg)
