Python使用os模块和fileinput模块来操作文件目录-Python Tutorial-php.cn

os模块
在python编程中,我们会经常使用到文件和目录,这些操作python提供一个os模块,里面有很多操作文件和目录的函数.

下面介绍os的常用功能

1.获取当前路径

>>> os.getcwd()
'/root/python'

Copy after login

2.获取目录中的内容

>>> os.listdir(os.getcwd())
['deco.py', '6.py', 'inputfile.py', 'uniFile.py', 'oddnogen.py', 'ospathex.py', 'operate.py', 'bianliang.py', 'typecheck1.py']

Copy after login

3.创建目录

>>> os.mkdir('/root/pythontest')

Copy after login

一次性创建嵌套目录可使用os.makedirs,makedirs可以生成多层递归目录，removedirs可以删除多层递归的空目录，若目录中有文件则无法删除;os.system()：运行shell命令；

>>> os.environ['HOME']
'/root'
>>> os.makedirs(os.path.join(os.environ['HOME'],'test','py'))
>>> os.system('ls -lR /root/test')
/root/test:
total 4
drwxr-xr-x 2 root root 4096 2013-03-29 17:27 py
 
/root/test/py:
total 0
0

Copy after login

4.改变工作目录

>>> os.getcwd()
'/root/python'
>>> os.chdir('/etc')
>>> os.getcwd()
'/etc'

Copy after login

5.删除目录

>>> os.rmdir('/root/pythontest')
>>>

Copy after login

6.删除文件

>>> os.remove('/root/pytest.py')

Copy after login

7.重命名文件或者目录

>>> os.rename('/root/pytest.py','/root/test.py')

Copy after login

8.字符串给出当前平台使用的终止符，例如：Windows使用'\r\n'，Linux使用'\n'

>>> os.linesep
'\n'

Copy after login

以下是os.path模块

9.判断是否是目录

>>> os.path.isdir('/root/python')
True

Copy after login

10.判断是否为文件

>>> os.path.isfile('/root/python')
False

Copy after login

11.返回一个路径的目录名和文件名

>>> os.path.split(os.getcwd())
('/root', 'python')

Copy after login

12.判断是否存在文件或目录name

>>> os.path.exists('/root')
True
>>> os.path.exists('/root/1.py')
False

Copy after login

13.获得文件大小

>>> os.path.getsize('/root/python/if.py')
282

Copy after login

14.返回文件路径,返回文件名

>>> os.path.dirname('/root/python/if.py')
'/root/python'
>>> os.path.basename('/root/python/if.py')
'if.py'

Copy after login

>>> os.path.join('/dave/test/','1.py')
'/dave/test/1.py'

Copy after login

>>> for file in os.listdir('/root/python'):
...   if os.path.isdir(file):
...     print file,"is a directory"
...   else:
...     print file,"is a file"
... 
deco.py is a file
inputfile.py is a file
operate.py is a file
hello.pyc is a file
userpw.py is a file
4.py is a file
answer is a directory

Copy after login

fileinput模块
fileinput模块可以遍历文本文件的所有行.它的工作方式和readlines很类似,不同点在于,它不是将全部的行读到列表中而是创建了一个xreadlines对象.

下面是fileinput模块中的常用函数

input() #它会返回能够用于for循环遍历的对象.
filename() #返回当前文件的名称
lineno() #返回当前(累计)的行数
filelineno() #返回当前文件的行数
isfirstline() #检查当前行是否是文件的第一行
close() #关闭序列

>>> import fileinput
>>> for eachline in fileinput.input("/root/datafile.txt"):
...   print eachline
... 
Dave
 
python
 
>>> for eachline in fileinput.input("/root/datafile.txt"):
...   print fileinput.filename()
... 
/root/datafile.txt
/root/datafile.txt
>>> for eachline in fileinput.input("/root/datafile.txt"):
...   print fileinput.lineno(),eachline
... 
1 Dave
 
2 python
 
>>> for eachline in fileinput.input("/root/datafile.txt"):
...   if fileinput.isfirstline():
...     print eachline
...   else:
...     break
... 
Dave

Copy after login

下面是一个关于日志分析的小实例,将日志中截取匹配的电话号码,如800-333-1212

root@10.1.1.45:~# cat telphone.log 
027-987-1212
02187899682
021-110-9632
root@10.1.1.45:~# cat fileinputtest.py 
#!/usr/bin/python2.5
 
import fileinput
import sys
import re
 
pattern = "\d{3}-\d{3}-\d{4}"
filePath = "/root/telphone.log"
 
for eachline in fileinput.input(filePath):
  a = re.search(pattern,eachline)
  if a:
#    sys.stdout.write("============\n")
#    sys.stdout.write(eachline)
     print "============"
     print 'line:',fileinput.lineno(),'filename:',fileinput.filename(),'length:',len(eachline.strip('\n')),eachline
root@10.1.1.45:~# ./fileinputtest.py 
============
line: 1 filename: /root/telphone.log length: 12 027-987-1212
 
============
line: 3 filename: /root/telphone.log length: 12 021-110-9632

Copy after login

Related labels：

fileinput os python

source：php.cn

Previous article：基于Python实现文件大小输出 Next article：详解Python发送邮件实例

Statement of this Website

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn