CODEWITHSUNDEEP
pythonstringpython-3.xlist-comprehension
Amir
Amir

Reputation: 11096

Efficient way to check if elements of a list contain all elements of another list

I have a list of strings named strList which contains around 800,000-2,200,000 elements. Each element contains around 100 characters. I have another list of strings called findStrs which usually contains less than 5 elements (5 to 10-character strings). I want to select the elements of strList that contain all of the elements in findStrs. How can I efficiently do that in Python? Here's how I am doing this but I wonder if there are more efficient solutions using list comprehensions for doing it:

finalStrList = []
for strr in strList:
    temp = []
    for findStr in findStrs:
        if findStr in strr:
            temp.append(findStr)
    if len(temp) == len(findStrs):
        finalStrList.append(str)
print(finalStrList)

I tried to devise a list comprehension-based method as well but, not surprisingly, it does not work:

[strr for strr in strList if [findStr in strr for findStr in findStrs]]

Upvotes: 1

Views: 1169

Answers (2)

guichao
guichao

Reputation: 198

If the match rate is not very high, we can reduce the time complexity.

finalStrList = []
for strr in strList:
    flag = True
    for findStr in findStrs:
        if findStr not in strr:
            flag = False
            break
    if flag:
        finalStrList.append(str)
print(finalStrList)

Upvotes: 0

Amir
Amir

Reputation: 11096

As juanpa.arrivillaga suggested in the comments section I can do what I want easily using the following list comprehension-based solution:

[s for s in strList if all([x in s for x in findStrs])]

Upvotes: 1

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