利用Python读取文件（针对大文件和小文件两种）的首行（第一行）和末行（最后一行）。脚本借鉴了前人的两种处理思路（在下面的脚本中有注释说明引用出处），并修正了原先两种处理方法中如果文件末尾含有多个空行而返回空行的问题。
脚本内容可以从GitHub上获取：
脚本内容如下：
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#!/usr/bin/python# encoding: utf-8# -*- coding: utf8 -*-"""Created by PyCharm.File: LinuxBashShellScriptForOps:getFileLastLine.pyUser: GuodongCreate Date: 2016/9/1Create Time: 11:05 """
import os
# Refer: http://www.pythonclub.org/python-files/last-linedef get_last_line(inputfile):
filesize = os.path.getsize(inputfile)
blocksize = 1024
dat_file = open(inputfile, 'rb')
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
# Refer: http://code.activestate.com/recipes/578095/def print_first_last_line(inputfile):
filesize = os.path.getsize(inputfile)
blocksize = 1024
dat_file = open(inputfile, 'rb')
headers = dat_file.readline().strip()
if filesize > blocksize:
maxseekpoint = (filesize // blocksize)
dat_file.seek(maxseekpoint * blocksize)
elif filesize:
maxseekpoint = blocksize % filesize
dat_file.seek(maxseekpoint)
lines = dat_file.readlines()
if lines:
last_line = lines[-1].strip()
# print "first line : ", headers
# print "last line : ", last_line
return headers, last_line
# My Implementationdef get_file_last_line(inputfile):
filesize = os.path.getsize(inputfile)
blocksize = 1024
with open(inputfile, 'rb') as f:
last_line = ""
if filesize > blocksize:
maxseekpoint = (filesize // blocksize)
f.seek((maxseekpoint - 1) * blocksize)
elif filesize:
f.seek(0, 0)
lines = f.readlines()
if lines:
lineno = 1
while last_line == "":
last_line = lines[-lineno].strip()
lineno += 1
return last_line
# Test purpose# print get_last_line(os.path.abspath(__file__))# print print_first_last_line(os.path.abspath(__file__))# print get_file_last_line(os.path.abspath(__file__)) |
--end--
本文转自 urey_pp 51CTO博客，原文链接：http://blog.51cto.com/dgd2010/1845139，如需转载请自行联系原作者