I have a list
data = [1, 2, 3, 0, 0, 4, 5, 0, 0, 0, 4, 6, 7, 0]
expected output
result = [[1,2,3], [4,5], [4,6,7]]
Split the list when a zero occur; add all the non-zero numbers to a new list till the next zero
This is what I have tried:
res = []
tmp = []
for i in data:
if i == 0 and len(tmp) > 0:
res.append(tmp)
tmp = []
elif i != 0:
tmp.append(i)
I am wondering is there a pythonic way of doing the same...
You can use itertools.groupby:
from itertools import groupby
data = [1, 2, 3, 0, 0, 4, 5, 0, 0, 0, 4, 6, 7, 0]
result = [list(g) for k, g in groupby(data, key=bool) if k]
# [[1, 2, 3], [4, 5], [4, 6, 7]]
The grouping key function uses the fact that bool maps 0 to False and all other ints to True. You could be more explicit and use
key=lambda n: n != 0
you can use more_itertools.split_at:
from more_itertools import split_at
data = [1, 2, 3, 0, 0, 4, 5, 0, 0, 0, 4, 6, 7, 0]
list(filter(None, split_at(data, lambda x: x==0 )))
output:
[[1, 2, 3], [4, 5], [4, 6, 7]]
