Create dict with unique keys and different list values from tuple
I have a list of tuples like this:
[('id1', 'text1', 0, 'info1'),
('id2', 'text2', 1, 'info2'),
('id3', 'text3', 1, 'info3'),
('id1', 'text4', 0, 'info4'),
('id4', 'text5', 1, 'info5'),
('id3', 'text6', 0, 'info6')]
I want to convert it to a dict, keeping IDs as keys and all other values as lists of tuples, expanding on those that exist:
{'id1': [('text1', 0, 'info1'),
('text4', 0, 'info4')],
'id2': [('text2', 1, 'info2')],
'id3': [('text3', 1, 'info3'),
('text6', 0, 'info6')],
'id4': [('text5', 1, 'info5')]}
Right now I am using pretty simple code:
for x in list:
if x[0] not in list: list[x[0]] = [(x[1], x[2], x[3])]
else: list[x[0]].append((x[1], x[2], x[3]))
I believe there must be a more elegant way to achieve the same result, perhaps with generators. Any ideas?
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1 answer
A useful method for adding to lists contained in a dictionary for solving such problems is dict.setdefault . You can use it to extract an existing list from the dictionary, or add an empty one if it is missing, for example:
data = [('id1', 'text1', 0, 'info1'),
('id2', 'text2', 1, 'info2'),
('id3', 'text3', 1, 'info3'),
('id1', 'text4', 0, 'info4'),
('id4', 'text5', 1, 'info5'),
('id3', 'text6', 0, 'info6')]
x = {}
for tup in data:
x.setdefault(tup[0], []).append(tup[1:])
Result:
{'id1': [('text1', 0, 'info1'), ('text4', 0, 'info4')],
'id2': [('text2', 1, 'info2')],
'id3': [('text3', 1, 'info3'), ('text6', 0, 'info6')],
'id4': [('text5', 1, 'info5')]}
Alternatively, you can use collection.defaultdict :
from collections import defaultdict
x = defaultdict(list)
for tup in data:
x[tup[0]].append(tup[1:])
which has similar results.
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