如何打印过滤结果所在的行？

Question

I'm trying to find a value from a txt that contains 2 words in a single line, the first word has to have a length longer than 10. I want my result to be printed with result and the line that my result is on.

I can find a value that first word is len>10, however I can't print the line number that my result is on, I've tried readline() , and it comes with error like AttributeError: 'list' object has no attribute 'readline'

Here is my code:

for line in open("birds.txt"):
  a = line.strip()
  word = a.split()
    if len(word[0])>10:
    c = word.readline()
print(a + " : " +c)

Answer 1

This is what your code would look like:
use with as a context manager so that the opened file would be closed at the end of operations ( in your case you're not closing the file, it's a bad practice).
To get the index AND the content at the same time you should use enumerate .
finally if you're using python > 3.6 you should use string formatting instead of concatenation since it's clearer and could lead to performance gains.

with open("birds.txt") as f:
    for index,line in enumerate(f):
        words = line.strip().split()
        if len(words[0])>10:
            print(f'{index} : {words[0]}')