Python fileinput模块使用实例
fileinput模块可以对一个或多个文件中的内容进行迭代、遍历等操作。 【典型用法】 复制代码 代码如下: import fileinput for line in fileinput.input(): process(line) 【基本格式】 复制代码 代码如下: fileinput.input([files[,inplace[,backup[,bufsize[,mode[,openhook]]]]]]) 【默认格式】 复制代码 代码如下: fileinput.input (files=None,inplace=False,backup='',bufsize=0,mode='r',openhook=None) files: #文件的路径列表,默认是stdin方式,多文件['1.txt','2.txt',...] inplace: #是否将标准输出的结果写回文件,默认不取代 backup: #备份文件的扩展名,只指定扩展名,如.bak。如果该文件的备份文件已存在,则会自动覆盖。 bufsize: #缓冲区大小,默认为0,如果文件很大,可以修改此参数,一般默认即可 mode: #读写模式,默认为只读 openhook: #该钩子用于控制打开的所有文件,比如说编码方式等; 【常用函数】 复制代码 代码如下: fileinput.input() #返回能够用于for循环遍历的对象 fileinput.filename() #返回当前文件的名称 fileinput.lineno() #返回当前已经读取的行的数量(或者序号) fileinput.filelineno() #返回当前读取的行的行号 fileinput.isfirstline() #检查当前行是否是文件的第一行 fileinput.isstdin() #判断最后一行是否从stdin中读取 fileinput.close() #关闭队列 【常见例子】 例子01: 利用fileinput读取一个文件所有行 复制代码 代码如下: >>> import fileinput >>> for line in fileinput.input('data.txt'): print line, #输出结果 Python Java C/C++ Shell 命令行方式: 复制代码 代码如下: #test.py import fileinput for line in fileinput.input(): print fileinput.filename(),'|','Line Number:',fileinput.lineno(),'|: ',line c:>python test.py data.txt data.txt | Line Number: 1 |: Python data.txt | Line Number: 2 |: Java data.txt | Line Number: 3 |: C/C++ data.txt | Line Number: 4 |: Shell 例子02: 利用fileinput对多文件操作,并原地修改内容 复制代码 代码如下: #test.py #---样本文件--- c:Python27>type 1.txt first second c:Python27>type 2.txt third fourth #---样本文件--- import fileinput def process(line): return line.rstrip() + ' line' for line in fileinput.input(['1.txt','2.txt'],inplace=1): print process(line) #---结果输出--- c:Python27>type 1.txt first line second line c:Python27>type 2.txt third line fourth line #---结果输出--- 命令行方式: 复制代码 代码如下: #test.py import fileinput def process(line): return line.rstrip() + ' line' for line in fileinput.input(inplace = True): print process(line) #执行命令 c:Python27>python test.py 1.txt 2.txt 例子03: 利用fileinput实现文件内容替换,并将原文件作备份 复制代码 代码如下: #样本文件: #data.txt Python Java C/C++ Shell #FileName: test.py import fileinput for line in fileinput.input('data.txt',backup='.bak',inplace=1): print line.rstrip().replace('Python','Perl') #或者print line.replace('Python','Perl'), #最后结果: #data.txt Python Java C/C++ Shell #并生成: #data.txt.bak文件 复制代码 代码如下: #其效果等同于下面的方式 import fileinput for line in fileinput.input(): print 'Tag:',line, #---测试结果: d:&;python Learn.py < data.txt > data_out.txt 例子04: 利用fileinput将CRLF文件转为LF 复制代码 代码如下: import fileinput import sys for line in fileinput.input(inplace=True): #将Windows/DOS格式下的文本文件转为Linux的文件 if line[-2:] == "rn": line = line + "n" sys.stdout.write(line) 例子05: 利用fileinput对文件简单处理 复制代码 代码如下: #FileName: test.py import sys import fileinput for line in fileinput.input(r'C:Python27info.txt'): sys.stdout.write('=> ') sys.stdout.write(line) #输出结果 >>> => The Zen of Python,by Tim Peters => => Beautiful is better than ugly. => Explicit is better than implicit. => Simple is better than complex. => Complex is better than complicated. => Flat is better than nested. => Sparse is better than dense. => Readability counts. => Special cases aren't special enough to break the rules. => Although practicality beats purity. => Errors should never pass silently. => Unless explicitly silenced. => In the face of ambiguity,refuse the temptation to guess. => There should be one-- and preferably only one --obvious way to do it. => Although that way may not be obvious at first unless you're Dutch. => Now is better than never. => Although never is often better than *right* now. => If the implementation is hard to explain,it's a bad idea. => If the implementation is easy to explain,it may be a good idea. => Namespaces are one honking great idea -- let's do more of those! 例子06: 利用fileinput批处理文件 复制代码 代码如下: #---测试文件: test.txt test1.txt test2.txt test3.txt--- #---脚本文件: test.py--- import fileinput import glob for line in fileinput.input(glob.glob("test*.txt")): if fileinput.isfirstline(): print '-'*20,'Reading %s...' % fileinput.filename(),'-'*20 print str(fileinput.lineno()) + ': ' + line.upper(), #---输出结果: >>> -------------------- Reading test.txt... -------------------- 1: AAAAA 2: BBBBB 3: CCCCC 4: DDDDD 5: FFFFF -------------------- Reading test1.txt... -------------------- 6: FIRST LINE 7: SECOND LINE -------------------- Reading test2.txt... -------------------- 8: THIRD LINE 9: FOURTH LINE -------------------- Reading test3.txt... -------------------- 10: THIS IS LINE 1 11: THIS IS LINE 2 12: THIS IS LINE 3 13: THIS IS LINE 4 例子07: 利用fileinput及re做日志分析: 提取所有含日期的行 复制代码 代码如下: #--样本文件-- aaa 1970-01-01 13:45:30 Error: **** Due to System Disk spacke not enough... bbb 1970-01-02 10:20:30 Error: **** Due to System Out of Memory... ccc #---测试脚本--- import re import fileinput import sys pattern = 'd{4}-d{2}-d{2} d{2}:d{2}:d{2}' for line in fileinput.input('error.log',inplace=1): if re.search(pattern,line): sys.stdout.write("=> ") sys.stdout.write(line) #---测试结果--- => 1970-01-01 13:45:30 Error: **** Due to System Disk spacke not enough... => 1970-01-02 10:20:30 Error: **** Due to System Out of Memory... 例子08: 利用fileinput及re做分析: 提取符合条件的电话号码 复制代码 代码如下: #---样本文件: phone.txt--- 010-110-12345 800-333-1234 010-99999999 05718888888 021-88888888 #---测试脚本: test.py--- import re import fileinput pattern = '[010|021]-d{8}' #提取区号为010或021电话号码,格式:010-12345678 for line in fileinput.input('phone.txt'): if re.search(pattern,line): print '=' * 50 print 'Filename:'+ fileinput.filename()+' | Line Number:'+str(fileinput.lineno())+' | '+line, #---输出结果:--- >>> ================================================== Filename:phone.txt | Line Number:3 | 010-99999999 ================================================== Filename:phone.txt | Line Number:5 | 021-88888888 >>> 例子09: 利用fileinput实现类似于grep的功能 复制代码 代码如下: import sys import re import fileinput pattern= re.compile(sys.argv[1]) for line in fileinput.input(sys.argv[2]): if pattern.match(line): print fileinput.filename(),fileinput.filelineno(),line $ ./test.py import.*re *.py #查找所有py文件中,含import re字样的 addressBook.py 2 import re addressBook1.py 10 import re addressBook2.py 18 import re test.py 238 import re 例子10: 利用fileinput做正则替换 复制代码 代码如下: #---测试样本: input.txt * [Learning Python](#author:Mark Lutz) #---测试脚本: test.py import fileinput import re for line in fileinput.input(): line = re.sub(r'* (.∗) #(.*)',r'<h2 id="2">1</h2>',line.rstrip()) print(line) #---输出结果: c:Python27>python test.py input.txt <h2 id="author:Mark Lutz">Learning Python</h2> 例子11: 利用fileinput做正则替换,不同字模块之间的替换 复制代码 代码如下: #---测试样本:test.txt [@!$First]&[*%-Second]&[Third] #---测试脚本:test.py import re import fileinput regex = re.compile(r'^([^&]*)(&)([^&]*)(&)([^&]*)') #整行以&分割,要实现[@!$First]与[*%-Second]互换 for line in fileinput.input('test.txt',inplace=1,backup='.bak'): print regex.sub(r'32145',line), #---输出结果: [*%-Second]&[@!$First]&[Third] 例子12: 利用fileinput根据argv命令行输入做替换 复制代码 代码如下: #---样本数据: host.txt # localhost is used to configure the loopback interface # when the system is booting. Do not change this entry. 127.0.0.1 localhost 192.168.100.2 www.test2.com 192.168.100.3 www.test3.com 192.168.100.4 www.test4.com #---测试脚本: test.py import sys import fileinput source = sys.argv[1] target = sys.argv[2] files = sys.argv[3:] for line in fileinput.input(files,openhook=fileinput.hook_encoded("gb2312")): #对打开的文件执行中文字符集编码 line = line.rstrip().replace(source,target) print line #---输出结果: c:&;python test.py 192.168.100 127.0.0 host.txt #将host文件中,所有192.168.100转换为:127.0.0 127.0.0.1 localhost 127.0.0.2 www.test2.com 127.0.0.3 www.test3.com 127.0.0.4 www.test4.com (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |