python清洗文件数据的方法

import io;

with open('a.txt', 'w') as f:   

    for line in open('c:/201509.txt'):   

        if line.find('更改项目')>0 and line.find('500')>0: 

            f.write(line+"\n");

print("输出完成");

import io;

def isData(s):

    return s.find('更改项目')>0 and s.find('500')>0;

with open('a.txt', 'w') as f:            

       list1=list(filter(isData,open('c:/201509.txt')));   

       for (offset,item) in enumerate(list1):

            f.write(str(offset)+":"+item);

import codecs

with codecs.open('a.txt','a', encoding='utf_8_sig') as f:

    for i in range(205,210):

        f.write(str(i)+"\r\n");  

        print(str(i));

        for line in open('c:/20160907'+str(i)+'.log', encoding='utf_8_sig'):

            if line.find('url为')>=0 : 

                print(line);

                f.write(line+"\r\n");

print("输出完成");