message_wrapping.py

#!/usr/bin/env python3

import doctest
import string


def break_into_chunks(message, allowance, characters_that_count_for_one, characters_that_count_for_two):

    cursor = 0
    allotted = 0

    result = list()

    while allotted < allowance and (cursor+1) < len(message):
        # Step forward in message and STOP when we run out space.
        if message[cursor] in characters_that_count_for_one:
            allotted += 1
        elif message[cursor] in characters_that_count_for_two:
            allotted += 2
        else:
            # nowwhat

        cursor = cursor + 1

    # Cursor is now at the end of the allowed space we COULD send a message in,
    # BUT that is not a nice place to break the message, so we need to find a
    # nice place to break it.
    # OR cursor is at the end of the whole message.

    while message[cursor] != ' ' and message[cursor] != '\n':
        # Now we walb backward with cursor to find a space 
        cursor = cursor - 1

    # Now cursor is at a space or newline.

    result.append(message[:cursor])

    return result



if __name__ == "__main__":
    print(break_into_chunks("one two three", 5, string.ascii_lowercase, string.ascii_uppercase))
    print(break_into_chunks("a b c", 3, string.ascii_lowercase, string.ascii_uppercase))