'int' object does not support item assignment. What does that mean?

# E.g. word_count("I am that I am") gets back a dictionary like:
# {'i': 2, 'am': 2, 'that': 1}
# Lowercase the string to make it easier.
# Using .split() on the sentence will give you a list of words.
# In a for loop of that list, you'll have a word that you can
# check for inclusion in the dict (with "if word in dict"-style syntax).
# Or add it to the dict with something like word_dict[word] = 1.
def word_count(string):
  word_dict = {}
  words = string.split()

  for word in words:
    try:
      if word_dict[word]:
        value = word_dict[word]
        word_dict = value + 1
    except:
      word_dict[word] = 1

  return word_dict