Question

Python 3

How do I add multiple non-integer values to a key in a dictionary?

Here's the code that this question came from. It's part of a larger program. text_string is a string and ngram_length is a user-defined integer. I tried using an if/else statement to initialize the dictionary with the first value and then to add subsequent values to the key but append doesn't work :(

def build_dictionary(text_string, ngram_length):
    dictionary = {}
    first = 0
    last = ngram_length
    while first < len(text_string) - ngram_length:
        if text_string[first:last] not in dictionary:
            dictionary[text_string[first:last]] = text_string[last]
        else:
            dictionary[text_string[first:last]].append(text_string[last])               #ERROR#
        first += ngram_length
        last += ngram_length
    print(dictionary)

Answer 1

def build_dictionary(text_string, ngram_length):
    dictionary = {}
    first = 0
    last = ngram_length
    while first < len(text_string) - ngram_length:
        if text_string[first:last] not in dictionary:
            dictionary[text_string[first:last]] = [text_string[last]]
        else:
            dictionary[text_string[first:last]].append(text_string[last])    
        first += ngram_length
        last += ngram_length
    print(dictionary)