python - 为什么我在 Python 中使用任何方法都这么慢？

Question

我正在尝试搜索字符串(句子)列表并检查它们是否包含一组特定的子字符串。为此，我使用了 Python 的“任意”函数

sentences = ["I am in London tonight",
                   "I am in San Fran tomorrow",
                   "I am in Paris next Wednesday"]

# Imagine the following lists to contain 1000's of strings 
listOfPlaces = ["london", "paris", "san fran"] 
listOfTimePhrases = ["tonight", "tomorrow", "week", "monday", "wednesday", "month"]

start = time.time()

sntceIdxofPlaces = [pos for pos, sent in enumerate(sentences) if any(x in sent for x in listOfPlaces)]
sntceIdxofTimes = [pos for pos, sent in enumerate(sentences) if any(x in pos for x in listOfTimePhrases)]

end = time.time()

print(end-start)

如果您想象我的列表非常大，我会发现我在两个“任何”语句上耗时相当长。对于两个这样的“任何”查询，我大约需要 2 秒。您知道为什么要花这么长时间吗？您知道有什么方法可以使代码更快吗？

谢谢

Answer 1

不要枚举你的句子两次。你可以用一个循环检查你的句子。

sntceIdxofPlaces = []
sntceIdxofTimes = []
for pos, sent in enumerate(sentences):
    if any(x in sent for x in listOfPlaces):
        sntceIdxofPlaces.append(pos)
    if any(x in sent for x in listOfTimePhrases):
        sntceIdxofTimes.append(pos)