Find number of occurrences of groups of '-' sign in list in Python

Question

it is my first question here.

I want to know how from this:

[1,1,2,'-','-',3,3,'-','-','-','-','-',5,5,'-','-','-']

find occurrences of '-' sign in this shape: [2,5,3]

Answer 1

you can use itertools groupby :

from itertools import groupby

l = [1, 1, 2, '-', '-', 3, 3, '-', '-', '-', '-', '-', 5, 5, '-', '-', '-']
result = [len(list(v)) for k, v in groupby(l) if k == '-']

OUTPUT:

[2, 5, 3]