检查列表的任何字符串是否出现在更大的字符串上

Question

我有一个字符串列表。我想检查该列表中的任何字符串是否出现在保存在字符串 var 中的更大文档中。我知道这可以通过循环轻松完成，但我将多次执行此操作（以及除此之外的另一个循环），所以我想知道是否有更有效的方法来代替 for 循环。我的方法是这样的：main_words = ... # List of words I want to checktweet = ... # String containing the text I want to check for word appearancefor word in main_words:    if word in tweet:        .......

Answer 1

您可以使用集合来获取此信息：

text = """I have a list of strings. I would like to check if any of the strings of 

that list appears on a bigger document saved on a string var.

I know this can easily be done with a loop, but I will be doing this operation so 

many times (and another loops apart of this) so I was wondering if there is any

more efficient way to do it instead of a for loop."""

words = set(["would","this","do","if","supercalifragelisticexpialigetic"])

text_words = text.split()

# show all that are in it

print(words.intersection(text_words))   # words & set(text_words)

# show all that are not in it

print(words.difference(text_words))     # words - set(text_words)

输出：

set(['this', 'do', 'would', 'if'])               # words & set(text_words)

set(['supercalifragelisticexpialigetic'])        # words - set(text_words)

要获得计数，请执行以下操作：

from collections import Counter

counted = Counter(text_words)

for w in words:

    print(w, counted.get(w))

输出：

do 1

would 1

supercalifragelisticexpialigetic None

if 2

this 2