Question

I realize this is a basic question but I cannot get this to work.
I have the following tuple:

t = (('apple', 'banana'), ('apple', 'carrot'), ('banana', 'carrot'))

I want the first item within every tuple in t to be unique, and to merge the second item of every duplicate together into a dictionary.

t = {('apple': 'banana', 'carrot'), ('banana': 'carrot')}

Not surprisingly, this doesn’t work:

t = dict(zip(set(t[0]),t[1]))

This is the result:

{'apple': 'apple', 'banana': 'carrot'}

Answer 1

I think, you should use a dict here (or rather a defaultdict). Where key of the dict would be the first element of your inner tuples – tup[0].

This is what you want:

>>> t = (('apple', 'banana'), ('apple', 'carrot'), ('banana', 'carrot'))
>>>
>>> from collections import defaultdict
>>> 
>>> temp_dict = defaultdict(tuple)
>>> 
>>> for tup in t:
        temp_dict[tup[0]] += tup[1:]  


>>> temp_dict
defaultdict(<type 'tuple'>, {'apple': ('banana', 'carrot'), 'banana': ('carrot',)})

>>> {key:value for key, value in temp_dict.items()}
{'apple': ('banana', 'carrot'), 'banana': ('carrot',)}