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on module posixpath

in

os:

NAME

posixpath

-

Common operations on Posix pathnames.

FILE

/

usr

/

lib

/

python2.

6

/

posixpath.py

MODULE DOCS

http:

/

docs.python.org

/

library

/

posixpath

DESCRIPTION

Instead of importing this module directly,

import

os

and

refer to

this module as os.path. The

"os.path"

name

is

an alias

for

this

module on Posix systems; on other systems (e.g. Mac, Windows),

os.path provides the same operations

in

a manner specific to that

platform,

and

is

an alias to another module (e.g. macpath, ntpath).

Some of this can actually be useful on non

-

Posix systems too, e.g.

for

manipulation of the pathname component of URLs.

#使用os.path

FUNCTIONS

abspath(path)

Return an absolute path.

#返回的绝对路径。

exp:>>> os.path.abspath(

'.'

)

'/root/python'

basename(p)

Returns the final component of a pathname

#返回一个路径名的最后一个组件，同split差不多，都是找最后以"/"+1结尾，并return p[i:]

exp:>>> os.path.basename(

'./new.txt'

)

'new.txt'

commonprefix(m)

Given a

list

of pathnames, returns the longest common leading component

#鉴于路径名的列表，返回的最长公共领先的组件

dirname(p)

Returns the directory component of a pathname

#返回一个路径名的目录部分,查找最后"/"+1的索引，并打印之前的数据。如果没有"/"则去掉，正常目录减掉最后那个"/"，非正常目录去除最后/右边的字符串。如果无"/"返回空

exp:>>> os.path.dirname(

'/root/python/new.txt'

)

'/root/python'

>>> os.path.dirname(

"a///a.txt"

)

'a'

>>> os.path.dirname(

"/a//c.ini"

)

'/a'

>>> a

=

"/ca.txt"

>>> b

=

a.rfind(

'/'

)

+

1

>>> b

14

>>> c

=

a[:b]

>>> c

'/c'

>>> c !

=

'/'

*

len

(c)

True

exists(path)

Test whether a path exists. Returns

False

for

broken symbolic links

#测试路径是否存在。损坏的符号链接返回False

exp:>>> os.path.exists(

'/root/python/new.txt'

)

rue

>>> os.path.exists(

'/root/python/new.tx'

)

False

expanduser(path)

Expand ~

and

~user constructions. If user

or

$HOME

is

unknown,

do nothing.

#返回用户的绝对路径

exp:>>> os.path.expanduser(

'~/python'

)

'/root/python'

expandvars(path)

Expand shell variables of form $var

and

${var}. Unknown variables

are left unchanged.

#展开变量$var和${var}

getatime(filename)

Return the last access time of a

file

, reported by os.stat().

#返回最后一次访问文件的时间，报告由os.stat（）。

exp:>>> os.path.getatime(

'./new.txt'

)

1369040605.3546476

>>> os.stat(

'./new.txt'

)

posix.stat_result(st_mode

=

33060

, st_ino

=

787083L

, st_dev

=

64768L

, st_nlink

=

1

, st_uid

=

0

, st_gid

=

0

, st_size

=

0L

, st_atime

=

1369040605

, st_mtime

=

1369040605

, st_ctime

=

1369043721

)

getctime(filename)

Return the metadata change time of a

file

, reported by os.stat().

#返回Ctime

getmtime(filename)

Return the last modification time of a

file

, reported by os.stat().

#返回mtime

getsize(filename)

Return the size of a

file

, reported by os.stat().

#返回一个文件的大小，报告的由os.stat（）。

isabs(s)

Test whether a path

is

absolute

#测试路径是否是绝对的,如果接收字符串是以'/'开头则返回True。

exp:>>> os.path.isabs(

'./new.txt'

)

False

>>> os.path.isabs(

'/root/python/new.txt'

)

True

isdir(s)

Return true

if

the pathname refers to an existing directory.

#如果是一个目录返回true

isfile(path)

Test whether a path

is

a regular

file

#如果是一个file返回true

islink(path)

Test whether a path

is

a symbolic link

#如果是一个link返回true

ismount(path)

Test whether a path

is

a mount point

#测试路径是否是一个挂载点

exp:>>> os.path.ismount(

'/python'

)

True

join(a,

*

p)

Join two

or

more pathname components, inserting

'/'

as needed.

If

any

component

is

an absolute path,

all

previous path components

will be discarded.

#将多个路径组合后返回，第一个绝对路径之前的参数将被忽略。

#如果*p以"/"开头直接返回*p，如果a等于空(exp )或者路径以"/"结尾(exp "/root/www/")则a+(*p)否则exp(./)'/'+(*p)

exp:>>> os.path.join(

"/root/python"

,

"a.txt"

)

'/root/python/a.txt'

lexists(path)

Test whether a path exists. Returns

True

for

broken symbolic links

#测试路径是否存在。返回True损坏的符号链接

exp:>>> os.path.lexists(

"/root/python"

)

True

>>> os.path.lexists(

"/root/python1"

)

False

normcase(s)

Normalize case of pathname. Has no effect under Posix

#正常化的路径名的情况下。在POSIX下直接返回原值。

exp:>>> os.path.normcase(

"c:\windows\system32"

)

'c:\\windows\\system32'

normpath(path)

Normalize path, eliminating double slashes, etc.

#正常化的路径，消除双斜线，等等。

exp:>>> os.path.normpath(

"c:\\windows"

)

'c:\\windows'

>>> os.path.normpath(

"\etc\\windows"

)

'\\etc\\windows'

>>> os.path.normpath(

"\etc\windows"

)

'\\etc\\windows'

>>> os.path.normpath(

"/etc\windows"

)

'/etc\\windows'

>>> os.path.normpath(

"/etc/windows"

)

'

/

etc

/

windows

realpath(filename)

Return the canonical path of the specified filename, eliminating

any

symbolic links encountered

in

the path.

#返回指定的文件名的规范路径，消除任何在通路中遇到的符号链接。

exp:>>> os.path.realpath(

'/root/python/a.txt'

)

'/root/python/a.txt'

relpath(path, start

=

'.'

)

Return a relative version of a path

#返回的路径相对版本，如果空值，返回错误"no path specified"

exp:

>>> os.path.relpath(

'/root/python/a.txt'

)

'a.txt'

samefile(f1, f2)

Test whether two pathnames reference the same actual

file

#测试两个路径名是否引用同一实际文件,如果2个路径指向同样的文件或目录，返回True

exp:>>> os.path.samefile(

'/root/python/a.txt'

,

'./b.txt'

)

False

>>> os.path.samefile(

'/root/python/a.txt'

,

'./a.txt'

)

True

sameopenfile(fp1, fp2)

Test whether two

open

file

objects reference the same

file

#测试两个打开的文件对象是否引用同一个文件

samestat(s1, s2)

Test whether two stat buffers reference the same

file

#测试两个stat缓冲区是否引用同一个文件

split(p)

Split a pathname. Returns

tuple

"(head, tail)"

where

"tail"

is

everything after the final slash. Either part may be empty.

#分割文件名与目录（事实上，如果你完全使用目录，它也会将最后一个目录作为文件名而分离，同时它不会判断文件或目录是否存在）

#找出"/"在(p)中出现的最后一次，并以倒数第二次以索引进行分割。

exp:>>> os.path.split(

"/root/python"

)

(

'/root'

,

'python'

)

>>> os.path.split(

"/root/python/a.txt"

)

(

'/root/python'

,

'a.txt'

)

>>> os.path.split(

"/root/python/"

)

(

'/root/python'

, '')

splitdrive(p)

Split a pathname into drive

and

path. On Posix, drive

is

always

empty.

# 作用于windows/dos/nt，在unix永远返回空。

splitext(p)

Split the extension

from

a pathname.

Extension

is

everything

from

the last dot to the end, ignoring

leading dots. Returns

"(root, ext)"

; ext may be empty.

#分离文件名与扩展名，以最后"."号分割，返回一个元组。

exp:>>> os.path.splitext(

"/root/python/a.txt"

)

(

'/root/python/a'

,

'.txt'

)

>>> os.path.splitext(

"a.txt"

)

(

'a'

,

'.txt'

)

>>> os.path.splitext(

"a.txt"

)

(

'a'

,

'.txt'

)

>>> os.path.splitext(

"/a.txt"

)

(

'/a'

,

'.txt'

)

>>> os.path.splitext(

"root/a.txt"

)

(

'root/a'

,

'.txt'

)

walk(top, func, arg)

Directory tree walk with callback function.

For each directory

in

the directory tree rooted at top (including top

itself, but excluding

'.'

and

'..'

), call func(arg, dirname, fnames).

dirname

is

the name of the directory,

and

fnames a

list

of the names of

the files

and

subdirectories

in

dirname (excluding

'.'

and

'..'

). func

may modify the fnames

list

in

-

place (e.g. via

del

or

slice

assignment),

and

walk will only recurse into the subdirectories whose names remain

in

fnames; this can be used to implement a

filter

,

or

to impose a specific

order of visiting. No semantics are defined

for

,

or

required of, arg,

beyond that arg

is

always passed to func. It can be used, e.g., to

pass

a filename pattern,

or

a mutable

object

designed to accumulate

statistics. Passing

None

for

arg

is

common.

#os.path.walk()

函数声明：walk(top,func,arg)

1

>参数top表示需要遍历的目录树的路径

2

>参数func表示回调函数，对遍历路径进行处理.所谓回调函数，是作为某个函数的参数使用，当某个时间触发时，程序将调用定义好的回调函数处理某个任务.回调函数必须提供

3

个参数：第

1

个参数为walk()的参数tag，第

2

个参数表示目录列表，第

3

个参数表示文件列表

3

>参数arg是传递给回调参数func的元组.回调函数的一个参数必须是arg，为回调函数提供处理参数.参数arg可以为空

exp:>>>

def

myvisit(a,

dir

, files):

...

print

dir

,

": %d files"

%

len

(files)

>>> os.path.walk(

'/root'

,myvisit,

None

)

/

root :

12

files

/

root

/

python :

3

files

/

root

/

python

/

[

0

-

4

] :

0

files

/

root

/

install :

5

files

/

root

/

install

/

nagios

-

plugins

-

1.4

.

16

:

53

files

/

root

/

install

/

nagios

-

plugins

-

1.4

.

16

/

pkg :

3

files

DATA

__all__

=

[

'normcase'

,

'isabs'

,

'join'

,

'splitdrive'

,

'split'

, 'splite...

altsep

=

None

curdir

=

'.'

defpath

=

':/bin:/usr/bin'

devnull

=

'/dev/null'

extsep

=

'.'

pardir

=

'..'

pathsep

=

':'

sep

=

'/'

supports_unicode_filenames

=

False