python - 多字表达式的字符串拆分问题

Question

我有一系列字符串，例如:

'i would like a blood orange'

我还有一个字符串列表，例如:

["blood orange", "loan shark"]

对字符串进行操作，我想要以下列表:

["i", "would", "like", "a", "blood orange"]

获取上述列表的最佳方式是什么？我在整个代码中一直使用 re，但我对这个问题感到困惑。

Answer 1

这是一个相当简单的生成器实现:将字符串拆分为单词，将形成短语的单词组合在一起，然后生成结果。

(可能有一种更简洁的方法来处理skip，但由于某种原因我画了一个空白。)

def split_with_phrases(sentence, phrase_list):
    words = sentence.split(" ")
    phrases = set(tuple(s.split(" ")) for s in phrase_list)
    print phrases
    max_phrase_length = max(len(p) for p in phrases)

    # Find a phrase within words starting at the specified index.  Return the
    # phrase as a tuple, or None if no phrase starts at that index.
    def find_phrase(start_idx):
        # Iterate backwards, so we'll always find longer phrases before shorter ones.
        # Otherwise, if we have a phrase set like "hello world" and "hello world two",
        # we'll never match the longer phrase because we'll always match the shorter
        # one first.
        for phrase_length in xrange(max_phrase_length, 0, -1):
            test_word = tuple(words[idx:idx+phrase_length])
            if test_word in phrases:
                return test_word
        return None

    skip = 0
    for idx in xrange(len(words)):
        if skip:
            # This word was returned as part of a previous phrase; skip it.
            skip -= 1
            continue

        phrase = find_phrase(idx)
        if phrase is not None:
            skip = len(phrase)
            yield " ".join(phrase)
            continue

        yield words[idx]

print [s for s in split_with_phrases('i would like a blood orange',
    ["blood orange", "loan shark"])]