检查列表并在python中拆分句子

Question

I have a list as follows.

mylist = ['test copy', 'test project', 'test', 'project']

I want to see if my sentence includes the aforementioned mylist elements and split the sentence from the first match and obtain its first part.

For example:

mystring1 = 'it was a nice test project and I enjoyed it a lot'

output should be: it was a nice

mystring2 = 'the example test was difficult'

output should be: the example

My current code is as follows.

for sentence in L:
    if mylist in sentence:
        splits = sentence.split(mylist)
        sentence= splits[0]

However, I get an error saying TypeError: 'in <string>' requires string as left operand, not list . Is there a way to fix this?

Answer 1

You need another for loop to iterate over every string in mylist .

mylist = ['test copy', 'test project', 'test', 'project']
mystring1 = 'it was a nice test project and I enjoyed it a lot'
mystring2 = 'the example test was difficult'

L = [mystring1, mystring2]
for sentence in L:
    for word in mylist:
        if word in sentence:
            splits = sentence.split(word)
            sentence= splits[0]
            print(sentence)
# it was a nice 
# the example

Answer 2

Probably the most effective way to do this is by first constructing a regex, that tests all the strings concurrently:

import re

split_regex = re.compile('|'.join(re.escape(s) for s in mylist))

for sentence in L:
    first_part = split_regex.split(sentence, 1)[0]

This yields:

>>> split_regex.split(mystring1, 1)[0]
'it was a nice '
>>> mystring2 = 'the example test was difficult'
>>> split_regex.split(mystring2, 1)[0]
'the example '

If the number of possible strings is large, a regex can typically outperform searching each string individually.

You probably also want to .strip() the string (remove spaces in the front and end of the string):

import re

split_regex = re.compile('|'.join(re.escape(s) for s in mylist))

for sentence in L:
    first_part = split_regex.split(sentence, 1)[0].strip()

Answer 3

mylist = ['test copy', 'test project', 'test', 'project']
L = ['it was a nice test project and I enjoyed it a lot','a test copy']
for sentence in L:
    for x in mylist:
        if x in sentence:
            splits = sentence.split(x)
            sentence= splits[0]
            print(sentence)

the error says you are trying to check a list in sentence. so you must iterate on elements of list.