Function to find the index of the beginning and end of the longest run in a list

Question

I\'m trying to write code that finds the longest run in a list of Boolean values and return the index of the first and last value of that run. For example, if L is [False, Fals

Answer 1

Use itertools.groupby:

from itertools import groupby

values = [False, False, True, False, False, False, False, True, True, False, False]

start = 0
runs = []
for key, run in groupby(values):
    length = sum(1 for _ in run)
    runs.append((start, start + length - 1))
    start += length

result = max(runs, key=lambda x: x[1] - x[0])
print(result)

Output

(3, 6)