python - wordList 中的两个元素

Question

我有这样一个功能:

def ladderLength(self, beginWord, endWord, wordList):
    """
    :type beginWord: str
    :type endWord: str
    :type wordList: List[str]
    :rtype: int
    """
    if (endWord not in wordList) or (beginWord not in wordList):
        return 0

多个bool操作很麻烦。

    if (endWord not in wordList) or (beginWord not in wordList):
        return 0

如何让它变得简洁明了？

Answer 1

如果你所有的 if-block 都是这样的:

  if (endWord not in wordList) or (beginWord not in wordList):
    return 0
  else:  # <- I am assuming this, see Note 1
    return 1

然后你可以将整个东西替换为:

return int(all(x in wordList for x in (endWord, beginWord)))

---

Note 1

Not having an else clause is generally perfectly fine but in your case you would have a function that might return 0 or None and that is not optimal\recommended. If you can, redesign it as per above.

If not, I wouldn't bother changing the condition. The one you have is very readable and there are no alternatives that are much better. Sure you could do:

if not all(x in wordList for x in (endWord, beginWord)):
    return 0

but that is pretty much it.