Efficiently split a string using multiple separators and retaining each separator?

Question

I need to split strings of data using each character from string.punctuation and string.whitespace as a separator.

Furthermore, I need for the

Answer 1

Solution in linear (O(n)) time:

Let's say you have a string:

original = "a, b...c    d"

First convert all separators to space:

splitters = string.punctuation + string.whitespace
trans = string.maketrans(splitters, ' ' * len(splitters))
s = original.translate(trans)

Now s == 'a b c d'. Now you can use itertools.groupby to alternate between spaces and non-spaces:

result = []
position = 0
for _, letters in itertools.groupby(s, lambda c: c == ' '):
    letter_count = len(list(letters))
    result.append(original[position:position + letter_count])
    position += letter_count

Now result == ['a', ', ', 'b', '...', 'c', ' ', 'd'], which is what you need.