Python return dictionary with corresponding letters

Question

The function should return the words if they match with a letter in the dictionary.

Example:

print(returnLetter(list1))

{'I': ['I'], 'say': ['say', 'what', 'mean', 'and'], 'what': ['say', 'what', 'mean', 'and'], 'mean': ['say', 'what', 'mean', 'and'], 
'and': ['say', 'what', 'mean', 'and']}

The function I currently have only returns it if it matches with the first letter, and I have been messing with the indexing and cannot figure it out.

def returnLetter(inpt):
result = {}
for word in inpt:
    char = word[0]
    if char in result:
        result[char].append(word)
    else:
        result[char] = [word]
return result

This will return every word with the first letter in the list, but it should be going through every letter instead of just the first.

Answer 1

Edit: Here's the edited code as required:

def return_letter(l: list):
    result = dict()
    # Creating starting dictionary
    for word in l:
        if word not in result.keys():
            result[word] = []

    # Iterating over keys and words in the list and adding all matching words
    for word, v in result.items():
        for letter in word:
            for w in result.keys():
                if w not in v and letter in w:
                    v.append(w)
    return result


text = "and I say what you mean"
print(return_letter(text.split(' ')))

output:

{'and': ['and', 'say', 'what', 'mean'], 'I': ['I'], 'say': ['say', 'and', 'what', 'mean', 'you'], 'what': ['what', 'and', 'say', 'mean'], 'you': ['say', 'you'], 'mean': ['mean', 'and', 'say', 'what']}

Hopefully, my code is clear enough, if something is unclear be sure to leave a comment.