def protect_shorthand(text, split_locations):
    """
    Annotate locations in a string that contain
    periods as being true periods or periods
    that are a part of shorthand (and thus should
    not be treated as punctuation marks).

    Arguments:
    ----------
        text : str
        split_locations : list<int>, same length as text.
    """
    word_matches = list(re.finditer(word_with_period, text))
    total_words = len(word_matches)

    for i, match in enumerate(word_matches):
        match_start = match.start()
        match_end = match.end()
        for char_pos in range(match_start, match_end):
            if split_locations[char_pos] == SHOULD_SPLIT and match_end - char_pos > 1:
                match_start = char_pos
        word = text[match_start:match_end]

        if not word.endswith('.'):
            # ensure that words contained within other words:
            # e.g. 'chocolate.Mountains of'  -> 'chocolate. Mountains of'
            if (not word[0].isdigit() and
                split_locations[match_start] == UNDECIDED):
                split_locations[match_start] = SHOULD_SPLIT
            continue
        period_pos = match_end - 1
        # this is not the last word, abbreviation
        # is not the final period of the sentence,
        # moreover:
        word_is_in_abbr = word[:-1].lower() in ABBR
        is_abbr_like = (
            word_is_in_abbr or
            one_letter_long_or_repeating.match(word[:-1]) is not None
        )
        is_digit = False if is_abbr_like else word[:-1].isdigit()

        is_last_word = i == (total_words - 1)
        is_ending = is_last_word and (match_end == len(text) or text[match_end:].isspace())
        is_not_ending = not is_ending
        abbreviation_and_not_end = (
            len(word) > 1 and
            is_abbr_like and
            is_not_ending
        )

        if abbreviation_and_not_end and (
                (not is_last_word and word_matches[i+1].group(0)[0].islower()) or
                (not is_last_word and word_matches[i+1].group(0) in PUNCT_SYMBOLS) or
                word[0].isupper() or
                word_is_in_abbr or
                len(word) == 2):
            # next word is lowercase (e.g. not a new sentence?), or next word
            # is punctuation or next word is totally uppercase (e.g. 'Mister.
            # ABAGNALE called to the stand')
            if split_locations[period_pos] == SHOULD_SPLIT and period_pos + 1 < len(split_locations):
                split_locations[period_pos + 1] = SHOULD_SPLIT
            split_locations[period_pos] = SHOULD_NOT_SPLIT
        elif (is_digit and
              len(word[:-1]) <= 2 and
              not is_last_word and
              word_matches[i+1].group(0).lower() in MONTHS):
            # a date or weird number with a period:
            if split_locations[period_pos] == SHOULD_SPLIT and period_pos + 1 < len(split_locations):
                split_locations[period_pos + 1] = SHOULD_SPLIT
            split_locations[period_pos] = SHOULD_NOT_SPLIT
        elif split_locations[period_pos] == UNDECIDED:
            # split this period into its own segment:
            split_locations[period_pos] = SHOULD_SPLIT
Annotate locations in a string that contain
    periods as being true periods or periods
    that are a part of shorthand (and thus should
    not be treated as punctuation marks).

    Arguments:
    ----------
        text : str
        split_locations : list<int>, same length as text.