def tokenize(phrase):
    """
    Split phrase words into a parts (tokens).
    The result can be useful for autocomplete purpose.

    Example:
        hello world => h,he,hel,hell,hello,w,wo,wor,worl,world
    """
    a = []
    for word in phrase.split():
        for i in range(len(word)):
            a.append(word[0:i + 1])
    return a