Python的os.path模块

• os.path.abspath(path) #返回绝对路径
• os.path.basename(path) #返回文件名
• os.path.commonprefix(list) #返回list(多个路径)中，所有path共有的最长的路径。
• os.path.dirname(path) #返回文件路径
• os.path.exists(path) #路径存在则返回True,路径损坏返回False
• os.path.lexists #路径存在则返回True,路径损坏也返回True
• os.path.expanduser(path) #把path中包含的”~”和”~user”转换成用户目录
• os.path.expandvars(path) #根据环境变量的值替换path中包含的”$name”和”${name}”
• os.path.getatime(path) #返回最后一次进入此path的时间。
• os.path.getmtime(path) #返回在此path下最后一次修改的时间。
• os.path.getctime(path) #返回path的大小
• os.path.getsize(path) #返回文件大小，如果文件不存在就返回错误
• os.path.isabs(path) #判断是否为绝对路径
• os.path.isfile(path) #判断路径是否为文件
• os.path.isdir(path) #判断路径是否为目录
• os.path.islink(path) #判断路径是否为链接
• os.path.ismount(path) #判断路径是否为挂载点（）
• os.path.join(path1[, path2[, …]]) #把目录和文件名合成一个路径
• os.path.normcase(path) #转换path的大小写和斜杠
• os.path.normpath(path) #规范path字符串形式
• os.path.realpath(path) #返回path的真实路径
• os.path.relpath(path[, start]) #从start开始计算相对路径
• os.path.samefile(path1, path2) #判断目录或文件是否相同
• os.path.sameopenfile(fp1, fp2) #判断fp1和fp2是否指向同一文件
• os.path.samestat(stat1, stat2) #判断stat tuple stat1和stat2是否指向同一个文件
• os.path.split(path) #把路径分割成dirname和basename，返回一个元组
• os.path.splitdrive(path) #一般用在windows下，返回驱动器名和路径组成的元组
• os.path.splitext(path) #分割路径，返回路径名和文件扩展名的元组
• os.path.splitunc(path) #把路径分割为加载点与文件
• os.path.walk(path, visit, arg) #遍历path，进入每个目录都调用visit函数，visit函数必须有3个参数(arg,dirname,names)，dirname表示当前目录的目录名，names代表当前目录下的所有文件名，args则为walk的第三个参数
• os.path.supports_unicode_filenames #设置是否支持unicode路径名

'''
C:Python27>python
Python 2.7.5 (default, May 15 2013, 22:44:16) [MSC v.1500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import os.path
>>> dir(os.path)
['__all__', '__builtins__', '__doc__', '__file__', '__name__', '__package__', '_abspath_split', '_getfullpathname', 'abspath', 'altsep', 'basename', 'commonprefix', 'curdir', 'defpath', 'devnull', 'dirname', 'exists', 'expanduser', 'expandvars', 'extsep', 'genericpath', 'getatime', 'getctime', 'getmtime', 'getsize', 'isabs', 'isdir', 'isfile', 'islink', 'ismount', 'join', 'lexists', 'normcase', 'normpath', 'os', 'pardir', 'pathsep', 'realpath', 'relpath', 'sep', 'split', 'splitdrive', 'splitext', 'splitunc', 'stat', 'supports_unicode_filenames', 'sys', 'walk', 'warnings']
>>>
>>> help(os.path)
Help on module ntpath:

NAME
ntpath - Common pathname manipulations, WindowsNT/95 version.

FILE
c:python27libntpath.py

DESCRIPTION
Instead of importing this module directly, import os and refer to this
module as os.path.

FUNCTIONS
abspath(path)
Return the absolute version of a path.

basename(p)
Returns the final component of a pathname

commonprefix(m)
Given a list of pathnames, returns the longest common leading component

dirname(p)
Returns the directory component of a pathname

exists(path)
Test whether a path exists. Returns False for broken symbolic links

expanduser(path)
Expand ~ and ~user constructs.

If user or $HOME is unknown, do nothing.

expandvars(path)
Expand shell variables of the forms $var, ${var} and %var%.

Unknown variables are left unchanged.

getatime(filename)
Return the last access time of a file, reported by os.stat().

getctime(filename)
Return the metadata change time of a file, reported by os.stat().

getmtime(filename)
Return the last modification time of a file, reported by os.stat().

getsize(filename)
Return the size of a file, reported by os.stat().

isabs(s)
Test whether a path is absolute

isdir = _isdir(...)
Return true if the pathname refers to an existing directory.

isfile(path)
Test whether a path is a regular file

islink(path)
Test for symbolic link.
On WindowsNT/95 and OS/2 always returns false

ismount(path)
Test whether a path is a mount point (defined as root of drive)

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.

lexists = exists(path)
Test whether a path exists. Returns False for broken symbolic links

normcase(s)
Normalize case of pathname.

Makes all characters lowercase and all slashes into backslashes.

normpath(path)
Normalize path, eliminating double slashes, etc.

realpath = abspath(path)
Return the absolute version of a path.

relpath(path, start='.')
Return a relative version of a path

split(p)
Split a pathname.

Return tuple (head, tail) where tail is everything after the final slash.
Either part may be empty.

splitdrive(p)
Split a pathname into drive and path specifiers. Returns a 2-tuple
"(drive,path)"; either part may be empty

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.

splitunc(p)
Split a pathname into UNC mount point and relative path specifiers.

Return a 2-tuple (unc, rest); either part may be empty.
If unc is not empty, it has the form '//host/mount' (or similar
using backslashes). unc+rest is always the input path.
Paths containing drive letters never have an UNC part.

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.

DATA
__all__ = ['normcase', 'isabs', 'join', 'splitdrive', 'split', 'splite...
altsep = '/'
curdir = '.'
defpath = r'.;C:bin'
devnull = 'nul'
extsep = '.'
pardir = '..'
pathsep = ';'
sep = r''
supports_unicode_filenames = True

>>>
'''

批量重命名：

import os, time, glob

for files in glob.glob('D:\photos\*.jpg'):
	filepath,filename = os.path.split(files)
	filterame,exts = os.path.splitext(filename)
	opfile = 'D:\photos2\'	# output path
	if (os.path.isdir(opfile)==False):
		os.mkdir(opfile)

path = os.path.normcase("D:/photos2/")
cc = time.gmtime()
bmpname = str(cc[0])+str(cc[1])+str(cc[2])+str(cc[3]+8)+str(cc[4])+str(cc[5])+'.bmp'
os.remove(bmpname)	# remove .bmp file
jpgname = bmpname[:-4]+'.jpg'
djpgname = path+jpgname
copy_command = "move %s %s" % (jpgname, djpgname)
os.popen(copy_command)

os.walk函数的一段代码示例（统计指定文件夹中的文件大小）：

import os
from os.path import join, getsize
for root, dirs, files in os.walk('python/Lib/email'):
    print root, "consumes",
    print sum([getsize(join(root, name)) for name in files]),
    print "bytes in", len(files), "non-directory files"
    if 'CVS' in dirs:
        dirs.remove('CVS')  # don't visit CVS directories

参考网址：

• os.path用法
• python os.path模块
• Python陷阱：raw string