Get only new lines from file

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Chapters
00:00 Get Only New Lines From File
00:46 Answer 1 Score 0
00:54 Accepted Answer Score 5
01:24 Answer 3 Score 2
01:29 Thank you

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Full question
https://stackoverflow.com/questions/2481...

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Content licensed under CC BY-SA
https://meta.stackexchange.com/help/lice...

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Tags
#python #python27 #logging #python3x

#avk47

ACCEPTED ANSWER

Score 5

You could initially read the file completely, then close it, and keep a change monitor over it, this monitor is implemented below using polling.

import time

filePath = '/var/log/logfile.log'

lastLine = None
with open(filePath,'r') as f:
        while True:
            line = f.readline()
            if not line:
                break
            print(line)
            lastLine = line

while True:
    with open(filePath,'r') as f:
        lines = f.readlines()
    if lines[-1] != lastLine:
        lastLine = lines[-1]
        print(lines[-1])
    time.sleep(1)

But you could also use tools like those described at: Detect File Change Without Polling

ANSWER 2

Score 2

with open('/var/log/logfile.log','r') as f:
    for line in f:
        print line

ANSWER 3

Score 0

Try This,

readfile = open('/var/log/logfile.log','r')
if readfile:
   for lines in readfile:
      print lines
readfile.close()