Make a dictionary with duplicate keys in Python

Question

I have the following list which contains duplicate car registration numbers with different values. I want to convert it into a dictionary which accepts this multiple keys of

Answer 1

You can't have a dict with duplicate keys for definition! Instead you can use a single key and, as value, a list of elements that had that key.

So you can follow these steps:

1. See if the current element's (of your initial set) key is in the final dict. If it is, go to step 3
2. Update dict with key
3. Append the new value to the dict[key] list
4. Repeat [1-3]