os.path
— 常见路径名操纵
¶
此模块实现一些有用路径名函数。要读取/写入文件见
open()
，和访问文件系统见
os
模块。
注意
On Windows, many of these functions do not properly support UNC pathnames.
splitunc()
and
ismount()
do handle them correctly.
不像 Unix Shell，Python 不做任何
automatic
路径扩展。函数譬如
expanduser()
and
expandvars()
可以被明确援引，当应用程序期望像 Shell 的路径扩展时。(另请参阅
glob
模块。)
注意
由于不同操作系统有不同的路径名约定，因此，此模块在标准库中有几个版本。
os.path
模块是始终适合在操作系统运行 Python 的路径模块，因此可用于本地路径。不管怎样，还可以导入和使用单独模块，若想要操纵的路径
always
是某种不同格式。它们都有相同接口：
posixpath
用于 UNIX 样式路径
ntpath
用于 Windows 路径
macpath
用于旧样式 MacOS 路径
os2emxpath
for OS/2 EMX paths
os.path.
abspath
(
path
)
¶
返回规范化绝对版本的路径名
path
。在大多数平台，这相当于调用函数
normpath()
如下：
normpath(join(os.getcwd(), path))
.
1.5.2 版新增。
os.path.
basename
(
path
)
¶
返回基名称为路径名
path
。这是返回对的第 2 元素通过传递
path
到函数
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 (
''
).
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 (
''
). Note that this may return invalid paths because it works a character at a time.
os.path.
exists
(
path
)
¶
返回
True
if
path
引用现有路径。返回
False
对于断开的符号链接。在某些平台，此函数可能返回
False
若未授予权限以执行
os.stat()
对请求文件，即使
path
物理存在。
os.path.
lexists
(
path
)
¶
返回
True
if
path
引用现有路径。返回
True
对于断开的符号链接。相当于
exists()
当平台缺乏
os.lstat()
.
2.4 版新增。
os.path.
expanduser
(
path
)
¶
在 Unix 和 Windows，返回自变量采用初始分量的
~
or
~user
替换
user
的 Home (主) 目录。
在 Unix，初始
~
的替换是通过环境变量
HOME
若有设置；否则在 password 目录下查找当前用户的 home 目录通过内置模块
pwd
。初始
~user
是直接在 password 目录下查找。
在 Windows，
HOME
and
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.
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}
.
os.path.
getatime
(
path
)
¶
Return the time of last access of
path
. The return value is a number giving the number of seconds since the epoch (see the
time
模块)。引发
os.error
若文件不存在 (或不可访问)。
1.5.2 版新增。
Changed in version 2.3:
若
os.stat_float_times()
返回
True
，结果是浮点数。
os.path.
getmtime
(
path
)
¶
Return the time of last modification of
path
. The return value is a number giving the number of seconds since the epoch (see the
time
模块)。引发
os.error
若文件不存在 (或不可访问)。
1.5.2 版新增。
Changed in version 2.3:
若
os.stat_float_times()
返回
True
，结果是浮点数。
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
模块)。引发
os.error
若文件不存在 (或不可访问)。
2.3 版新增。
os.path.
isabs
(
path
)
¶
返回
True
if
path
是绝对路径名。在 Unix，这意味着它以斜杠开始，在 Windows，它以 (反) 斜杠开始在砍掉潜在驱动器字母后。
os.path.
isfile
(
path
)
¶
返回
True
if
path
is an existing regular file. This follows symbolic links, so both
islink()
and
isfile()
可以为 True 对于相同路径。
os.path.
isdir
(
path
)
¶
返回
True
if
path
is an existing directory. This follows symbolic links, so both
islink()
and
isdir()
可以为 True 对于相同路径。
os.path.
islink
(
path
)
¶
返回
True
if
path
refers to a directory entry that is a symbolic link. Always
False
若 Python 运行时不支持符号链接。
os.path.
ismount
(
path
)
¶
返回
True
若路径名
path
是
mount point
: a point in a file system where a different file system has been mounted. 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.
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 (
os.sep
) 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
.
os.path.
normcase
(
path
)
¶
Normalize the case of a pathname. On Unix and Mac OS X, this returns the path unchanged; on case-insensitive filesystems, it converts the path to lowercase. On Windows, it also converts forward slashes to backward slashes.
os.path.
normpath
(
path
)
¶
通过折叠多余分隔符和上层引用以规范化路径名，以便
A//B
,
A/B/
,
A/./B
and
A/foo/../B
全部变为
A/B
。此字符串操纵可能改变包含符号链接的路径含义。在 Windows，它将正斜杠转换为反斜杠。要规范化大小写，使用
normcase()
.
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)。
2.2 版新增。
os.path.
relpath
(
path
[
,
start
]
)
¶
返回相对文件路径为 path 从当前目录或从可选 start 目录。这种路径计算：不用访问文件系统就能确认存在 (或性质) 为 path or start .
start
默认为
os.curdir
.
Availability: Windows, Unix.
2.6 版新增。
os.path.
samefile
(
path1
,
path2
)
¶
返回
True
if both pathname arguments refer to the same file or directory (as indicated by device number and i-node number). Raise an exception if an
os.stat()
call on either pathname fails.
可用性：Unix。
os.path.
sameopenfile
(
fp1
,
fp2
)
¶
返回
True
若文件描述符
fp1
and
fp2
参考同一文件。
可用性：Unix。
os.path.
samestat
(
stat1
,
stat2
)
¶
返回
True
若状态元组
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。
os.path.
split
(
path
)
¶
分割路径名
path
成一对
(head, tail)
where
tail
是最后路径名分量而
head
是至此的一切前导。
tail
部分从不包含斜杠；若
path
以斜杠结尾，
tail
将为空。若没有斜杠在
path
,
head
将为空。若
path
为空，两者
head
and
tail
为空。剥离结尾斜杠从
head
除非它是 root (仅一个或多个斜杠)。在所有情况下，
join(head, tail)
返回同一位置路径如
path
(但字符串可能不同)。另请参阅函数
dirname()
and
basename()
.
os.path.
splitdrive
(
path
)
¶
分割路径名
path
成一对
(drive, tail)
where
drive
is either a drive specification or the empty string. On systems which do not use drive specifications,
drive
始终是空字符串。在所有情况下，
drive
+ tail
将如同
path
.
New in version 1.3.
os.path.
splitext
(
path
)
¶
分割路径名
path
成一对
(root, ext)
这样
root + ext ==
path
，和
ext
is empty or begins with a period and contains at most one period. Leading periods on the basename are ignored;
splitext('.cshrc')
返回
('.cshrc', '')
.
2.6 版改变： Earlier versions could produce an empty root when the only period was the first character.
os.path.
splitunc
(
path
)
¶
分割路径名
path
成一对
(unc, rest)
so that
unc
is the UNC mount point (such as
r'\\host\mount'
), if present, and
rest
the rest of the path (such as
r'\path\file.ext'
). For paths containing drive letters,
unc
will always be the empty string.
可用性：Windows。
os.path.
walk
(
path
,
visit
,
arg
)
¶
Calls the function
visit
采用自变量
(arg, dirname, names)
for each directory in the directory tree rooted at
path
(including
path
itself, if it is a directory). The argument
dirname
specifies the visited directory, the argument
名称
lists the files in the directory (gotten from
os.listdir(dirname)
)。
visit
function may modify
名称
to influence the set of directories visited below
dirname
, e.g. to avoid visiting certain parts of the tree. (The object referred to by
名称
must be modified in place, using
del
or slice assignment.)
注意
Symbolic links to directories are not treated as subdirectories, and that
walk()
therefore will not visit them. To visit linked directories you must identify them with
os.path.islink(file)
and
os.path.isdir(file)
, and invoke
walk()
as necessary.
注意
This function is deprecated and has been removed in Python 3 in favor of
os.walk()
.
os.path.
supports_unicode_filenames
¶
True
若可以将任意 Unicode 字符串用作文件名 (在由文件系统施加的局限性内)。
2.3 版新增。