I know how to update values in a dictionary. That's easy, and there are multiple ways to do it. However, what I'm looking for is how to add to a value in a dictionary. For example:

    def frequency_dictionary(words):
      new_dict = {}
      for word in words:
        if word not in new_dict:
          new_dict[word] = 1
        else:
           #?????
      return new_dict

I want this function to add 1 to the value of a word for each time it is featured in the words list. For example, print(frequency_dictionary(["apple", "apple", "cat", 1])) should return {"apple":2, "cat":1, 1:1}. The comment in the function with question marks is the part I am stuck on. What are some options to do this?

I tried looking this up, but all I got was info on how to update values, not add to them.

I am currently using a while loop to loop and get certain values. I then want to append these values to a dictionary. Every loop through I want to append to two keys

General structure of the code: https://pastebin.com/p4hJcKR5

I have tried using:

dict[key] = value

dict.append(value)

And neither have worked, dict.append gives an error and dict[key] just sets the dictionary to the most recent iteration instead of iterating for all values. Any help would be appreciated.

I am trying to add a list, or a tuple of lists, as the value to a key inside a dictionary. I'm starting with a dictionary that has empty lists as values, and then adding to the value of each key inside a loop like this:

dict = {'key1': [], 'key2': [], 'key3': []}
list = ['a', 'b']
for key,value in dict.items():
#    dict[key].append(list)
    value.append(list)
print(dict)

What is the difference between dict[key].append(list) and value.append(list)? They both produce the same dictionary when the other is commented out.

Further, how would I add a second list to one of these values as a tuple? Something like adding the list ['c', 'd'] to key2, like this:

{'key1': [['a', 'b']], 'key2': [['a', 'b'], ['c', 'd']], 'key3': [['a', 'b']]}

Thanks for any replies!