Space/speed effective string by word cutting algorithm

ellipsis.py

from ctypes import c_uint32


def ellipsis(string: str, str_length: int, suffix: str = '...') -> str:
    max_len: int = str_length + 1
    space: str = ' '
    if len(string) > max_len:
        if string[max_len] == space:
            return string[:max_len] + suffix
        else:
            cursor: c_uint32 = c_uint32(str_length)
            while cursor.value > 0:
                if string[cursor.value] != space:
                    cursor.value -= 1
                else:
                    return string[:cursor.value] + suffix
            return None
    else:
        return string