Question

I have a question about the accepted answer for this question.

Could you explain why this code:

[{'type':k, 'items':v} for k,v in res.items()]

do the job, i.e. it combines items to list in with same key.

Answer 1

Could you explain [{'type':k, 'items':v} for k,v in res.items()]

Let’s take it apart:

1. for k,v in res.items() iterates over the entries of res, assigning each key and value to k and v respectively.
2. {'type':k, 'items':v} creates a two-element dictionary. The first element has key 'type' and value k; the second element has key 'items' and value v.
3. The effect of the list comprehension [...] is that each entry in res gets converted into a dictionary as explained in step 2, and the resulting dictionaries are stored in a list.