Question

I want to copy pairs from this dictionary based on their values so they can be assigned to new variables. From my research it seems easy to do this based on keys, but in my case the values are what I’m tracking.

things = ({'alpha': 1, 'beta': 2, 'cheese': 3, 'delta': 4})

And in made-up language I can assign variables like so –

smaller_things =  all values =3 in things 

Answer 1

You can use .items() to traverse through the pairs and make changes like this:

smaller_things = {}
for k, v in things.items():
    if v == 3:
        smaller_things[k] = v

If you want a one liner and only need the keys back, list comprehension will do it:

smaller_things = [k for k, v in things.items() if v == 3]

>>> things = { 'a': 3, 'b': 2, 'c': 3 }
>>> [k for k, v in things.items() if v == 3]
['a', 'c']