寫一個類似linux head的小工具，在window下用。

head.py 

# -*- coding: UTF-8 -*-#!/usr/bin/python# by Jakcing 2019.02.17# print first n lines or last n lines in big file   import sysimport getoptimport linecache  VERSION="1.1" def get_line_count(filename): line_count = 0 file = open(filename,'r+', encoding='utf-8') while True: buffer = file.read(8192 * 1024 ) if not buffer:  break line_count += buffer.count('/n') file.close() return line_count def read_head_line(flist, line_num): for file_name in flist: print("===%s===" % file_name) f = open(file_name, 'r', encoding='utf-8') if(f):  for i in range(line_num):  print(f.readline(), end='')   def read_last_line(flist, line_num):  for file_name in flist:  linecache.clearcache() line_count = get_line_count(file_name) print('===%s=== line count total: %d' % (file_name, line_count)) line_count = line_count - line_num +1 print('===%s=== line %d to end' % (file_name, line_count))   for i in range(line_num):  last_line = linecache.getline(file_name, line_count) #從第line_count行讀起  print('line[%d]:%s' % (line_count, last_line), end='')  line_count += 1   try: opts, args = getopt.getopt(sys.argv[1:], "hvn:t:", ["help", "output=", "numline=", "tail=", "version"])except getopt.GetoptError:  print("argv error,please input") for cmd, arg in opts: if cmd in ("-h", "--help"): print("usage: head.py -n number filename /nor head.py -t number filename") sys.exit() elif cmd in ("-n", "--numline"): #打印文件開頭的line_num行 line_num=int(arg) file_names=args[:] read_head_line(file_names, line_num) elif cmd in ("-t", "--tail"): #打印文件結尾的line_num行 line_num=int(arg) file_names=args[:] read_last_line(file_names, line_num)  elif cmd in ("-v", "--version"): print("%s %s" % (sys.argv[0], VERSION)) sys.exit()

以上這篇python打印文件的前幾行或最后幾行教程就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持武林站長站。