python - 在python中按一定顺序查找子字符串

Question

我有一个很长的字符串列表，其中包含按给定顺序排列的感兴趣的子字符串，但这里是一个使用文本文件中的句子的小示例:

This is a long drawn out sentence needed to emphasize a topic I am trying to learn.
It is new idea for me and I need your help with it please!
Thank you so much in advance, I really appreciate it.

从此文本文件中，我想找到同时包含 "I" 和 "need" 的任何句子，但它们必须按该顺序出现。

所以在这个例子中，'I'和'need'都出现在句子1和句子2中，但在句子1中它们的顺序是错误的，所以我不想返回。我只想返回第二句话，因为它按顺序具有 'I need' 。

我使用这个示例来识别子字符串，但我不知道如何仅按顺序找到它们:

id1 = "I"
id2 = "need"

with open('fun.txt') as f:
    for line in f:
        if id1 and id2 in line:
            print(line[:-1])

这将返回:

This is a long drawn out sentence needed to emphasize a topic I am trying to learn.
It is new idea for me and I need your help with it please!

但我只想要:

It is new idea for me and I need your help with it please!

谢谢!

Answer 1

您需要在id1:

之后行的部分中识别 id2

infile = [
    "This is a long drawn out sentence needed to emphasize a topic I am trying to learn.",
    "It is new idea for me and I need your help with it please!",
    "Thank you so much in advance, I really appreciate it.",
]

id1 = "I"
id2 = "need"

for line in infile:
    if id1 in line:
        pos1 = line.index(id1)
        if id2 in line[pos1+len(id1) :] :
            print(line)

输出:

It is new idea for me and I need your help with it please!