os.path — 常见路径名操纵 ¶

源代码： Lib/posixpath.py (对于 POSIX) 和 Lib/ntpath.py (对于 Windows NT)。

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此模块实现一些有用路径名功能。要读取或写入文件，见 open() ，和要访问文件系统，见 os module. The path parameters can be passed as either strings, or bytes. Applications are encouraged to represent file names as (Unicode) character strings. Unfortunately, some file names may not be representable as strings on Unix, so applications that need to support arbitrary file names on Unix should use bytes objects to represent path names. Vice versa, using bytes objects cannot represent all file names on Windows (in the standard mbcs encoding), hence Windows applications should use string objects to access all files.

不像 Unix Shell，Python 不做任何 automatic 路径扩展。函数譬如 expanduser() and expandvars() can be invoked explicitly when an application desires shell-like path expansion. (See also the glob 模块。)

os.path. abspath ( path ) ¶

返回规范化绝对版本的路径名 path . On most platforms, this is equivalent to calling the function normpath() 如下： normpath(join(os.getcwd(), path)) .

3.6 版改变： 接受 像路径对象 .

os.path. basename ( path ) ¶

返回基名称为路径名 path . This is the second element of the pair returned by passing path to the function split() . Note that the result of this function is different from the Unix basename program; where basename for '/foo/bar/' 返回 'bar' ， basename() 函数返回空字符串 ( '' ).

3.6 版改变： 接受 像路径对象 .

os.path. commonpath ( paths ) ¶

Return the longest common sub-path of each pathname in the sequence paths 。引发 ValueError if paths contain both absolute and relative pathnames, the paths are on the different drives or if paths is empty. Unlike commonprefix() ，这返回有效路径。

可用性 : Unix, Windows.

3.5 版新增。

3.6 版改变： 接受序列的 像路径对象 .

os.path. commonprefix ( list ) ¶

Return the longest path prefix (taken character-by-character) that is a prefix of all paths in list 。若 list is empty, return the empty string ( '' ).

注意

This function may return invalid paths because it works a character at a time. To obtain a valid path, see commonpath() .

>>> os.path.commonprefix(['/usr/lib', '/usr/local/lib'])
'/usr/l'
>>> os.path.commonpath(['/usr/lib', '/usr/local/lib'])
'/usr'
										

3.6 版改变： 接受 像路径对象 .

os.path. dirname ( path ) ¶

Return the directory name of pathname path . This is the first element of the pair returned by passing path to the function split() .

3.6 版改变： 接受 像路径对象 .

os.path. exists ( path ) ¶

返回 True if path refers to an existing path or an open file descriptor. Returns False for broken symbolic links. On some platforms, this function may return False if permission is not granted to execute os.stat() on the requested file, even if the path physically exists.

3.3 版改变： path 现在可以是整数： True is returned if it is an open file descriptor, False 否则。

3.6 版改变： 接受 像路径对象 .

os.path. lexists ( path ) ¶

返回 True if path refers to an existing path. Returns True for broken symbolic links. Equivalent to exists() on platforms lacking os.lstat() .

3.6 版改变： 接受 像路径对象 .

os.path. expanduser ( path ) ¶

On Unix and Windows, return the argument with an initial component of ~ or ~user replaced by that user ’s home directory.

在 Unix，初始 ~ is replaced by the environment variable HOME if it is set; otherwise the current user’s home directory is looked up in the password directory through the built-in module pwd . An initial ~user is looked up directly in the password directory.

在 Windows， USERPROFILE will be used if set, otherwise a combination of HOMEPATH and HOMEDRIVE will be used. An initial ~user is handled by stripping the last directory component from the created user path derived above.

If the expansion fails or if the path does not begin with a tilde, the path is returned unchanged.

3.6 版改变： 接受 像路径对象 .

3.8 版改变： No longer uses HOME 在 Windows。

os.path. expandvars ( path ) ¶

Return the argument with environment variables expanded. Substrings of the form $name or ${name} are replaced by the value of environment variable name . Malformed variable names and references to non-existing variables are left unchanged.

在 Windows， %name% expansions are supported in addition to $name and ${name} .

3.6 版改变： 接受 像路径对象 .

os.path. getatime ( path ) ¶

Return the time of last access of path . The return value is a floating point number giving the number of seconds since the epoch (see the time module). Raise OSError if the file does not exist or is inaccessible.

os.path. getmtime ( path ) ¶

Return the time of last modification of path . The return value is a floating point number giving the number of seconds since the epoch (see the time module). Raise OSError if the file does not exist or is inaccessible.

3.6 版改变： 接受 像路径对象 .

os.path. getctime ( path ) ¶

Return the system’s ctime which, on some systems (like Unix) is the time of the last metadata change, and, on others (like Windows), is the creation time for path . The return value is a number giving the number of seconds since the epoch (see the time module). Raise OSError if the file does not exist or is inaccessible.

3.6 版改变： 接受 像路径对象 .

os.path. getsize ( path ) ¶

Return the size, in bytes, of path 。引发 OSError if the file does not exist or is inaccessible.

3.6 版改变： 接受 像路径对象 .

os.path. isabs ( path ) ¶

返回 True if path is an absolute pathname. On Unix, that means it begins with a slash, on Windows that it begins with a (back)slash after chopping off a potential drive letter.

3.6 版改变： 接受 像路径对象 .

os.path. isfile ( path ) ¶

返回 True if path 是 existing regular file. This follows symbolic links, so both islink() and isfile() can be true for the same path.

3.6 版改变： 接受 像路径对象 .

os.path. isdir ( path ) ¶

返回 True if path 是 existing directory. This follows symbolic links, so both islink() and isdir() can be true for the same path.

3.6 版改变： 接受 像路径对象 .

os.path. islink ( path ) ¶

返回 True if path refers to an existing directory entry that is a symbolic link. Always False if symbolic links are not supported by the Python runtime.

3.6 版改变： 接受 像路径对象 .

os.path. ismount ( path ) ¶

返回 True if pathname path 是 mount point : a point in a file system where a different file system has been mounted. On POSIX, the function checks whether path ’s parent, path/.. , is on a different device than path , or whether path/.. and path point to the same i-node on the same device — this should detect mount points for all Unix and POSIX variants. It is not able to reliably detect bind mounts on the same filesystem. On Windows, a drive letter root and a share UNC are always mount points, and for any other path GetVolumePathName is called to see if it is different from the input path.

3.4 版新增： Support for detecting non-root mount points on Windows.

3.6 版改变： 接受 像路径对象 .

os.path. join ( path , *paths ) ¶

Join one or more path components intelligently. The return value is the concatenation of path and any members of *paths with exactly one directory separator following each non-empty part except the last, meaning that the result will only end in a separator if the last part is empty. If a component is an absolute path, all previous components are thrown away and joining continues from the absolute path component.

On Windows, the drive letter is not reset when an absolute path component (e.g., r'\foo' ) is encountered. If a component contains a drive letter, all previous components are thrown away and the drive letter is reset. Note that since there is a current directory for each drive, os.path.join("c:", "foo") represents a path relative to the current directory on drive C: ( c:foo ), not c:\foo .

3.6 版改变： 接受 像路径对象 for path and paths .

os.path. normcase ( path ) ¶

Normalize the case of a pathname. On Windows, convert all characters in the pathname to lowercase, and also convert forward slashes to backward slashes. On other operating systems, return the path unchanged.

3.6 版改变： 接受 像路径对象 .

os.path. normpath ( path ) ¶

Normalize a pathname by collapsing redundant separators and up-level references so that A//B , A/B/ , A/./B and A/foo/../B all become A/B . This string manipulation may change the meaning of a path that contains symbolic links. On Windows, it converts forward slashes to backward slashes. To normalize case, use normcase() .

注意

On POSIX systems, in accordance with IEEE Std 1003.1 2013 Edition; 4.13 Pathname Resolution , if a pathname begins with exactly two slashes, the first component following the leading characters may be interpreted in an implementation-defined manner, although more than two leading characters shall be treated as a single character.

3.6 版改变： 接受 像路径对象 .

os.path. realpath ( path ) ¶

返回指定文件名的典型路径，消除路径中遇到的任何符号链接 (若操作系统支持它们)。

注意

当符号链接循环发生时，返回路径将是循环成员之一，但不保证是哪个成员。

3.6 版改变： 接受 像路径对象 .

3.8 版改变： 符号链接和结现在在 Windows 得到解决。

os.path. relpath ( path , start=os.curdir ) ¶

Return a relative filepath to path either from the current directory or from an optional start directory. This is a path computation: the filesystem is not accessed to confirm the existence or nature of path or start 。在 Windows， ValueError is raised when path and start are on different drives.

start 默认为 os.curdir .

可用性 : Unix, Windows.

3.6 版改变： 接受 像路径对象 .

os.path. samefile ( path1 , path2 ) ¶

返回 True if both pathname arguments refer to the same file or directory. This is determined by the device number and i-node number and raises an exception if an os.stat() call on either pathname fails.

可用性 : Unix, Windows.

3.2 版改变： 添加 Windows 支持。

3.4 版改变： Windows 现在使用与所有其它平台相同的实现。

3.6 版改变： 接受 像路径对象 .

os.path. sameopenfile ( fp1 , fp2 ) ¶

返回 True if the file descriptors fp1 and fp2 refer to the same file.

可用性 : Unix, Windows.

3.2 版改变： 添加 Windows 支持。

3.6 版改变： 接受 像路径对象 .

os.path. samestat ( stat1 , stat2 ) ¶

返回 True if the stat tuples stat1 and stat2 refer to the same file. These structures may have been returned by os.fstat() , os.lstat() ，或 os.stat() . This function implements the underlying comparison used by samefile() and sameopenfile() .

可用性 : Unix, Windows.

3.4 版改变： 添加 Windows 支持。

3.6 版改变： 接受 像路径对象 .

os.path. split ( path ) ¶

分割路径名 path into a pair, (head, tail) where tail is the last pathname component and head is everything leading up to that. The tail part will never contain a slash; if path ends in a slash, tail will be empty. If there is no slash in path , head will be empty. If path is empty, both head and tail are empty. Trailing slashes are stripped from head unless it is the root (one or more slashes only). In all cases, join(head, tail) returns a path to the same location as path (but the strings may differ). Also see the functions dirname() and basename() .

3.6 版改变： 接受 像路径对象 .

os.path. splitdrive ( path ) ¶

分割路径名 path into a pair (drive, tail) where drive is either a mount point or the empty string. On systems which do not use drive specifications, drive will always be the empty string. In all cases, drive + tail will be the same as path .

On Windows, splits a pathname into drive/UNC sharepoint and relative path.

If the path contains a drive letter, drive will contain everything up to and including the colon:

>>> splitdrive("c:/dir")
("c:", "/dir")
									

If the path contains a UNC path, drive will contain the host name and share, up to but not including the fourth separator:

>>> splitdrive("//host/computer/dir")
("//host/computer", "/dir")
									

3.6 版改变： 接受 像路径对象 .

os.path. splitext ( path ) ¶

分割路径名 path into a pair (root, ext) 这样 root + ext == path , and the extension, ext , is empty or begins with a period and contains at most one period.

If the path contains no extension, ext 将是 '' :

>>> splitext('bar')
('bar', '')
									

If the path contains an extension, then ext will be set to this extension, including the leading period. Note that previous periods will be ignored:

>>> splitext('foo.bar.exe')
('foo.bar', '.exe')
									

Leading periods on the basename are ignored:

>>> splitext('.cshrc')
('.cshrc', '')
									

3.6 版改变： 接受 像路径对象 .

os.path. supports_unicode_filenames ¶

True if arbitrary Unicode strings can be used as file names (within limitations imposed by the file system).

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