Python implements the method of reading the last n line of the file
- 2020-05-26 09:35:10
- OfStack
This article illustrates how the Python implementation reads the last n line of the file. I will share it with you for your reference as follows:
# -*- coding:utf8-*-
import os
import time
import datetime
import math
import string
def get_last_line(inputfile) :
filesize = os.path.getsize(inputfile)
blocksize = 1024
dat_file = open(inputfile, 'r')
last_line = ""
lines = dat_file.readlines()
count = len(lines)
if count>60:
num=60
else:
num=count
i=1;
lastre = []
for i in range(1,(num+1)):
if lines :
n = -i
last_line = lines[n].strip()
#print "last line : ", last_line
dat_file.close()
#print i
lastre.append(last_line)
return lastre
# To obtain the final 1 The results of
re = get_last_line('../update/log/rtime/rtime20130805.log')
print len(re)
for n in re:
strlist = n.split(' ')
if strlist[1] == 'ok' and string.atoi(strlist[2])>1000:
print ' The number of data bars is normal '
print 'OK'
else:
print ' Too little data, check email '
The above processing and log file format is
2013-08-05 16:09:30 ok 1673
2013-08-05 16:10:34 ok 1628
2013-08-05 16:11:55 ok 71
2013-08-05 16:13:02 ok 1441
2013-08-05 16:14:06 ok 1634
2013-08-05 16:15:10 ok 1717
2013-08-05 16:16:14 ok 1687
2013-08-05 16:17:18 ok 1642
2013-08-05 16:18:27 ok 1655
2013-08-05 16:19:33 ok 1655
Read the last 1 line:
# Back to the file 1 Line function
def get_last_line(inputfile) :
filesize = os.path.getsize(inputfile)
blocksize = 1024
dat_file = open(inputfile, 'r')
last_line = ""
if filesize > blocksize :
maxseekpoint = (filesize // blocksize)
dat_file.seek((maxseekpoint-1)*blocksize)
elif filesize :
#maxseekpoint = blocksize % filesize
dat_file.seek(0, 0)
lines = dat_file.readlines()
if lines :
last_line = lines[-1].strip()
#print "last line : ", last_line
dat_file.close()
return last_line
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I hope this article has been helpful to you in Python programming.