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Python Python Testing Be Assertive assertRaises

assert raises, just can't understand the question.

Im trying to pass this question but just couldn't understand what's telling me to do. i looked at the code that was in the video and still didn't get what I'm suppose to do, any suggestions are appreciated ?

tests.py
import unittest

from string_fun import get_anagrams


class AnagramTestCase(unittest.TestCase):
    def test_empty_string(self):
        with self.assertRaises(ValueError):
            get_anagrams()
string_fun.py
import itertools


def is_palindrome(yarn):
    """Return whether or not a string is a palindrome.

    A palindrome is a word/phrase that's the same in
    both directions.
    """
    return yarn == yarn[::-1]


def get_anagrams(*yarn):
    """Return a list of anagrams for a string."""
    # If only one letter came in, return it
    if yarn:
        if len(yarn[0]) == 1:
            return list(yarn)
        elif len(yarn[0] == 0):
            raise ValueError("Must provide at least two letters")
    else:
        raise ValueError("Must provide at least two letters")

    # Get all of the words from the dictionary
    words = set([
        w.strip().lower() for w in open('words.txt')
    ])

    output = set()
    for thread in yarn:
        thread = thread.lower()
        # Find all possible anagrams
        for i in range(2, len(thread)):
            fibers = set(
                [''.join(w) for w in itertools.permutations(thread, i)]
            )
            output.update(fibers.intersection(words))

    # Finally, return all of the combinations that are in the dictionary
    return sorted(list(output))

1 Answer

Ryan S
Ryan S
27,275 Points

Hi Ammar,

The challenge wants you to set up a unittest to make sure that when get_anagrams gets an empty string passed in, it raises a ValueError. Your logic is correct, but don't forget that get_anagrams takes an argument.

Good luck.

Can you please explain to me how am i suppose to do it ? in the video, it shows that he used with so that's what i used. I just need to know if the code below is on the right side and if so, what am i suppose to write as an output for the with This is the code I'm talking about

with self.assertRaises(ValueError):
    get_anagrams(ValueError)

I'm sorry if im annoying you, its just that i couldn't understand the way to do it.

Never mind, i got the hang of it :) thanks for the explanation