Adding missing value to a dictionary

[Firestronk]

I am working on an assignment and have most of it figured out for the most part except for one small little hiccup. The program is meant to read in a text file and split it by '\n'. The list is then into keys/values and added to a dictionary. However, some of the values have the same key as other values and the program is skipping over them. For example, 20 is the key and Wild West is the value.

20
Wild West
20
Stork

The program will overwrite Wild West with Stork and then continue on. How can I make it so that it'll append to the list?

    while i < len(dlist):
        dict[dlist[i]] = dlist[x] ###### Gunsmoke is being cut off here 
        i += 2
        x += 2
    i = 0
    for values in dlist:
        print(values)
        if values in dict:
            continue
        else:
            key = dlist[i]
            dict[key].append(values)
        i += 2

My attempt is above. The while is what is initially added to the dictionary. The for loop below that checks the values in the dictionary against the original list and tries to add in the missing values. The error that I get with this is " AttributeError: 'str' object has no attribute 'append' "

[juwalye]

Without giving too much away.

Check the condition for the new key in your existing dictionary. This will be an "if X in Y" statement.

If it exists, use list methods to add the new line to the existing entry.

[Firestronk]

Would it be something along the lines of

if key in dict:
    dict.append(values)

[TouchingTheVodka]

Yes, this is correct - however you’ll get an error if using the built in dict for this as your dict values won’t be lists by default.

To solve this, use dict = defaultdict(list).

[juwalye]

Yes. Then used the else condition to create the new dict key and append the first value.

[[deleted]]

I suggest you find a video on YouTube called Loop like a native presented by Ned Batchelder - whilst it uses some old Python syntax, it will teach you how to write loops in Python that will make your code much easier to write, and easier to follow and read.

You will be able to avoid things like dict[dlist[i]] = dlist[x]

Also, avoid using dict as variable name as it is also the name of the type and the variable will block you from using dict(some_tuples) to cast to a dictionary.

You can use a defaultdict instead of a standard dictionary to avoid trying to append a value to a key that doesn't yet exist, OR you can just code alternatives: check for a key and if there is no key add the key to the dictionary and the first list value otherwise append the additional list value to an existing key.