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Ian Cole
454 PointsSo Close! Help with dictionary keys
So I've got the program to assign each word to a key, and if it's a duplicate word it just assigns to the same value. But I can't get the duplicate key to increase the value. Every method I've tried so far has just given a KeyError
# E.g. word_count("I do not like it Sam I Am") gets back a dictionary like:
# {'i': 2, 'do': 1, 'it': 1, 'sam': 1, 'like': 1, 'not': 1, 'am': 1}
# Lowercase the string to make it easier.
def word_count(string):
lower_string = string.lower()
split_string = lower_string.split(" ")
word_dict = {}
for word in split_string:
word_dict[word] = 1
return word_dict
1 Answer
Alex Koumparos
Python Development Techdegree Student 36,887 PointsHi Ian,
The problem I think you've been running into when incrementing the word in the dictionary is the first time you try to do it, there is no key with that name. Your code above executes because you can assign an initial value to a new dictionary key (of course):
my_dict['new_key'] = 1
But you can't initialise that key by incrementing:
my_dict['another_new_key'] += 1
since you can't add one to something that doesn't exist.
They way that I solved it was in the for loop to first check whether the word was a member of the keys list (word_dict.keys()), then if it was, to increment that value (since I've obviously already set that dictionary item to a value). If not, to initialise that key with the value 1 (i.e., the line you have in your code example).
Hope that helps,
Cheers
Alex