python标准库学习2

列出指定目录中的所有文件：

import os
for file in os.listdir( "../src" ):
    print file

获得，修改当前的目录

import os
# where are we?
cwd = os.getcwd()
print "1", cwd

# go down
os.chdir( "../" )
print "2", os.getcwd()

# go back up
os.chdir( os.pardir )
print "3", os.getcwd()

创建目录，删除目录

import os

fp = open( "../src/levels/file", "w" )
fp.write( "inspector praline" )
fp.close()

os.remove( "../src/levels/file" )
os.removedirs( "../src/levels" )

返回文件的信息：

import os
import time

file = "../src/hello.xml"

def dump( st ):
    mode, ino, dev, nlink, uid, gid, size, atime, mtime, ctime = st
    print "- size:", size, "bytes"
    print "- owner:", uid, gid
    print "- created:", time.ctime( ctime )
    print "- last accessed:", time.ctime( atime )
    print "- last modified:", time.ctime( mtime )
    print "- mode:", oct( mode )
    print "- inode/dev:", ino, dev

#
# get stats for a filename

st = os.stat( file )

print "stat", file
dump( st )
print

#
# get stats for an open file

fp = open( file )

st = os.fstat( fp.fileno() )

print "fstat", file
dump( st )

笔者的输出结果为：

stat ../src/hello.xml

- size: 274 bytes

- owner: 0 0

- created: Sun Aug 07 20:45:31 2011

- last accessed: Mon Aug 08 12:34:28 2011

- last modified: Mon Aug 08 12:34:28 2011

- mode: 0100666

- inode/dev: 0 0

fstat ../src/hello.xml

- size: 274 bytes

- owner: 0 0

- created: Sun Aug 07 20:45:31 2011

- last accessed: Mon Aug 08 12:34:28 2011

- last modified: Mon Aug 08 12:34:28 2011

- mode: 0100666

- inode/dev: 6192449487670266 0

处理文件名

import os

filename = "my/little/pony"

print "using", os.name, "..."
print "split", "=>", os.path.split( filename )
print "splitext", "=>", os.path.splitext( filename )
print "dirname", "=>", os.path.dirname( filename )
print "basename", "=>", os.path.basename( filename )
print "join", "=>", os.path.join( os.path.dirname( filename ),
                                 os.path.basename( filename ) )

输出为;using nt ...

split => ('my/little', 'pony')

splitext => ('my/little/pony', '')

dirname => my/little

basename => pony

join => my/little\pony

注意这里的 ``split`` 只分割出最后一项(不带斜杠).