Question

I have one question about writing a dictionary given a file. I have done the coding but I am really confused. The parameter name is “load_words: (file)” and the output expected is “dict of {str: list of strs}“.

The description of the problem given is:

“The open file contains one lowercase word per line. Return a dictionary in which each key is a single lowercase letter and each value is a list of the words from the file that start with that letter. Only letters that one or more words from the file start with appear as keys in the dictionary. “

I am trying to write my code for

def load_words(file1):

I really don’t know how to approach this question any help would be appreciated any hints or even a complete solution and I could work backwards.

NOTE: IS NOT A HOMEWORK PROBLEM. I have a midterm in 2 days and I am trying to do the past midterms so please help

Answer 1

The simplest way to do this is to use collections.defaultdict as follows:

def load_words(file1):
    answer = collections.defaultdict(list)
    for line in file1:
        line = line.strip()
        if line not in answer[line[0]]:
            answer[line[0]].append(line)
    return answer

However, for your midterm, your professor might be expecting this answer:

def load_words(file1):
    answer = {}
    for line in file1:
        line = line.strip()
        if line[0] in answer: # or in answer.keys() or in answer.iterkeys()
            if line not in answer[line[0]]:
                answer[line[0]].append(line)
        else:
            answer[line[0]] = [line] # or answer[line[0]] = []; answer[line[0]].append(line)
    return answer

Hope that helps