計算檔案行數

count = len(open(filepath,'rU').readlines())

計算檔案行數(1GB以上的)

import linecache 
count = linecache.getline(filename,linenum)

str = linecache.getlines(filename)

計算很大的檔案

#!/usr/bin/python
# -*- coding: utf-8 -*-

''' count the number of lines when file is big '''

count=0
fp=open("filename.txt","r")
while 1:
	buffer=fp.read(8*1024*1024)
	if not buffer:
		break
	count+=buffer.count('\n')
	print count
print count
print 'over'
fp.close()