Python 检查 - 查找文件中关键字匹配的最后一次出现，然后检查正则表达式

Question

我有一个文本文件:花.txt

文件内容:

flower white
flower red
flower green
flower blue
Have some other text to the end of file.

我想 grep 该行，即单词“flower”的最后一次出现，并验证该行是否为“flower blue”。

不确定哪个函数有助于执行此操作。

import re

with open('flower.txt', "r") as f:

re.find 有帮助吗？？？

Answer 1

给你:

with open('temp.txt','w') as f:
    f.write('''\
flower white
flower red
flower green
flower blue
Have some other text to the end of file.''')

with open('temp.txt') as f:
    flowerlines = [i.strip() for i in f.readlines() if i.startswith('flower')]

if flowerlines:
    print(flowerlines[-1] == 'flower blue')
else:
    print('No flowers found.')

或者你可以这样:

searchW = 'flower blue'
with open('temp.txt') as f:
    flowerlines = next((i == searchW  for i in f.read().split('\n')[::-1] 
                        if i.startswith('flower')),'No flowers')
    print(flowerlines)

<小时/>

如果您需要优化它(很可能您不应该)，您可以看看这个:https://stackoverflow.com/a/23646049/7386332