Extract only the last line using read() function

Question

I'm using the following code for some text analysis (I've more code for the analysis):

with open(os.path.join(root, file)) as auto:
    a = auto.read(50000)
    for line in auto:
      print(line)

My question is: how can I print only the last line of the file?

I try this approach but I don't think it is a good option since it doesn't return any message:

with open(os.path.join(root, file)) as auto:
            a = auto.read(50000)
            lines = a.readlines()
            last_line = lines[-1]
            for line in auto:
                print(last_line)

How can I print the last line of the file using auto.read()?

Thanks

you can count file lines (wc -l file) and seek at last line number — Wonka, Apr 09 '19 at 14:43
Possible duplicate of [What is the most efficient way to get first and last line of a text file?](https://stackoverflow.com/questions/3346430/what-is-the-most-efficient-way-to-get-first-and-last-line-of-a-text-file) — , Apr 09 '19 at 14:49

DirtyBit · Accepted Answer · 2019-04-09T15:02:19.673

1

Perhaps:

list.txt:

sdfs
sdfs
fg34
345
gn
4564

Hence:

with open('list.txt') as fileObj:
    print(list(fileObj)[-1])

Using pathlib:

from pathlib import Path
print(Path('list.txt').read_text().splitlines()[-1])

OUTPUT:

edited Apr 09 '19 at 15:02

answered Apr 09 '19 at 14:53

DirtyBit

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score 0 · Answer 2 · answered Apr 09 '19 at 14:52

You wrote that

I try this approach but I don't think it is a good option since it doesn't return any message:

and then asked for a technique using read(). However, I think your approach is reasonable and it does work (though I suspect that the file you're reading has a blank line as the last line of the file). For example, this does indeed print the last line of the file:

import os
with open('test.py') as auto:
    lines = auto.readlines()
    last_line = lines[-1]
    print(last_line)

Extract only the last line using read() function

2 Answers2