CODEWITHSUNDEEP
pythonlisttuples
Giovanni Soldi
Giovanni Soldi

Reputation: 405

Find intervals given a list of tuples

I have the following Python list of tuples:

a  = [(1,2,'MARCO'),(3,4,'MARCO'),(5,6,'MARCO'),(7,8,'MARCO'),(9,11,'CARLO'),(12,13,'CARLO'),(14,15,'CARLO'),(16,17,'MARCO'),(18,19,'MARCO'),(20,21,'MARCO'),(22,23,'MARCO')]

In each tuple the first element is the starting time, the second element the end time and the third the speaker active in that segment. What is an efficient way to group consecutive intervals with the same speaker and having the total initial time and the total final time?

More specifically, the output I'd like to obtain is something like the following:

b = [(1,8,'MARCO'),(9,15,'CARLO'),(16,23,'MARCO')]

Upvotes: 2

Views: 530

Answers (1)

Tim Pietzcker
Tim Pietzcker

Reputation: 336258

How about a little handmade fun with the itertools module? This assumes that your list is ordered by rising starting "times".

from itertools import groupby
def speaker_times(a):
    result = []
    for item in groupby(a, lambda x:x[2]):  # Group by speaker name
        values = list(item[1])              # Convert iterator to list
        result.append((min(values)[0], max(values)[1], item[0]))
    return result

Result:

In [12]: speaker_times(a)
Out[12]: [(1, 8, 'MARCO'), (9, 15, 'CARLO'), (16, 23, 'MARCO')]

Upvotes: 7

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