Answer by pun_intended for Simplifying a Scrabble Word Finder - Python

Editing the code based on the feedback from everyone below, this is what I've come up with:

LETTER_SCORE = {"a": 1, "c": 3, "b": 3, "e": 1, "d": 2, "g": 2,
         "f": 4, "i": 1, "h": 4, "k": 5, "j": 8, "m": 3,
         "l": 1, "o": 1, "n": 1, "q": 10, "p": 3, "s": 1,
         "r": 1, "u": 1, "t": 1, "w": 4, "v": 4, "y": 4,
         "x": 8, "z": 10}

def calc_score(word):
    """Calculate the score of a given word."""
    return sum(LETTER_SCORE[letter] for letter in word)

def get_dictionary(filename):
    """Read a dictionary of valid scrabble words."""
    with open(filename, "r") as sowpods:
        return sowpods.read().split("\n")

def can_spell(word, rack):
    """Determine if a word can be spelled with the given rack."""
    letter_bank = list(rack)
    for letter in word:
        if letter not in letter_bank:
            return False
        letter_bank.remove(letter)
    return True

def make_valid_list(rack):
    """Make a list of all words that can be spelled with a given rack of letters."""
    return [word for word in get_dictionary("sowpods.txt") if can_spell(word, rack)]

def score_valid_words(rack):
    """Create a dictionary of the words with their scores."""
    valid_words = []
    for word in make_valid_list(rack):
        valid_words.append([word, calc_score(word)])
    return valid_words

def main():
    """For the letters in a user-specified rack, return the scores for
    all possible words checked against the SOWPODS dictionary for
    validity, and print the word and score for each in descending order."""
    vocabulary = get_dictionary("sowpods.txt")
    rack_letters = raw_input("Letters: ").lower()
    word_list = make_valid_list(rack_letters)
    word_scores = score_valid_words(rack_letters)
    for pair in sorted(word_scores, key=lambda k: k[1], reverse=True):
        if pair[1] > 0:
               print pair[0], "-", pair[1]

if __name__ == "__main__":
    main()

A quick breakdown of the changes:

• Opted for more comprehensions in the functions.
• Tried to make the functions and references a bit more descriptive, while breaking down some functions that were doing too much.
• Added a main() function as well as a if __name__ == "__main__": parameter at the end. I'm still not too confident on the usage of that one, but I think it does what it needs to do in this circumstance.
• Removed the most of the hard coded constants in favour of parameters that could be more easily transferred.

Thanks to everyone for the replies, they were a huge help. I don't know if it's necessary to write the main() function as it is, but for the moment, I put all the info recommended in there (though not exactly as recommended...)