Most Pythonic Way to Split an Array by Repeating Elements

Question

I have a list of items that I want to split based on a delimiter. I want all delimiters to be removed and the list to be split when a delimiter occurs twice. F

Answer 1

Here's a way to do it with itertools.groupby():

import itertools

class MultiDelimiterKeyCallable(object):
    def __init__(self, delimiter, num_wanted=1):
        self.delimiter = delimiter
        self.num_wanted = num_wanted

        self.num_found = 0

    def __call__(self, value):
        if value == self.delimiter:
            self.num_found += 1
            if self.num_found >= self.num_wanted:
                self.num_found = 0
                return True
        else:
            self.num_found = 0

def split_multi_delimiter(items, delimiter, num_wanted):
    keyfunc = MultiDelimiterKeyCallable(delimiter, num_wanted)

    return (list(item
                 for item in group
                 if item != delimiter)
            for key, group in itertools.groupby(items, keyfunc)
            if not key)

items = ['a', 'b', 'X', 'X', 'c', 'd', 'X', 'X', 'f', 'X', 'g']

print list(split_multi_delimiter(items, "X", 2))

I must say that cobbal's solution is much simpler for the same results.