def isabs(s):
"""Test whether a path is absolute"""
s = os.fspath(s)
s = splitdrive(s)[1]
return len(s) > 0 and s[0] in _get_bothseps(s)
# Join two (or more) paths.
python类fspath()的实例源码
def ismount(path):
"""Test whether a path is a mount point (a drive root, the root of a
share, or a mounted volume)"""
path = os.fspath(path)
seps = _get_bothseps(path)
path = abspath(path)
root, rest = splitdrive(path)
if root and root[0] in seps:
return (not rest) or (rest in seps)
if rest in seps:
return True
if _getvolumepathname:
return path.rstrip(seps) == _getvolumepathname(path).rstrip(seps)
else:
return False
# Expand paths beginning with '~' or '~user'.
# '~' means $HOME; '~user' means that user's home directory.
# If the path doesn't begin with '~', or if the user or $HOME is unknown,
# the path is returned unchanged (leaving error reporting to whatever
# function is called with the expanded path as argument).
# See also module 'glob' for expansion of *, ? and [...] in pathnames.
# (A function should also be defined to do full *sh-style environment
# variable expansion.)
def abspath(path):
"""Return the absolute version of a path."""
path = os.fspath(path)
if not isabs(path):
if isinstance(path, bytes):
cwd = os.getcwdb()
else:
cwd = os.getcwd()
path = join(cwd, path)
return normpath(path)
def normcase(s):
"""Normalize case of pathname. Has no effect under Posix"""
s = os.fspath(s)
if not isinstance(s, (bytes, str)):
raise TypeError("normcase() argument must be str or bytes, "
"not '{}'".format(s.__class__.__name__))
return s
# Return whether a path is absolute.
# Trivial in Posix, harder on the Mac or MS-DOS.
def isabs(s):
"""Test whether a path is absolute"""
s = os.fspath(s)
sep = _get_sep(s)
return s.startswith(sep)
# Join pathnames.
# Ignore the previous parts if a part is absolute.
# Insert a '/' unless the first part is empty or already ends in '/'.
def 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. An empty last part will result in a path that
ends with a separator."""
a = os.fspath(a)
sep = _get_sep(a)
path = a
try:
if not p:
path[:0] + sep #23780: Ensure compatible data type even if p is null.
for b in map(os.fspath, p):
if b.startswith(sep):
path = b
elif not path or path.endswith(sep):
path += b
else:
path += sep + b
except (TypeError, AttributeError, BytesWarning):
genericpath._check_arg_types('join', a, *p)
raise
return path
# Split a path in head (everything up to the last '/') and tail (the
# rest). If the path ends in '/', tail will be empty. If there is no
# '/' in the path, head will be empty.
# Trailing '/'es are stripped from head unless it is the root.
def splitdrive(p):
"""Split a pathname into drive and path. On Posix, drive is always
empty."""
p = os.fspath(p)
return p[:0], p
# Return the tail (basename) part of a path, same as split(path)[1].
def basename(p):
"""Returns the final component of a pathname"""
p = os.fspath(p)
sep = _get_sep(p)
i = p.rfind(sep) + 1
return p[i:]
# Return the head (dirname) part of a path, same as split(path)[0].
def dirname(p):
"""Returns the directory component of a pathname"""
p = os.fspath(p)
sep = _get_sep(p)
i = p.rfind(sep) + 1
head = p[:i]
if head and head != sep*len(head):
head = head.rstrip(sep)
return head
# Is a path a symbolic link?
# This will always return false on systems where os.lstat doesn't exist.
def abspath(path):
"""Return an absolute path."""
path = os.fspath(path)
if not isabs(path):
if isinstance(path, bytes):
cwd = os.getcwdb()
else:
cwd = os.getcwd()
path = join(cwd, path)
return normpath(path)
# Return a canonical path (i.e. the absolute location of a file on the
# filesystem).
def realpath(filename):
"""Return the canonical path of the specified filename, eliminating any
symbolic links encountered in the path."""
filename = os.fspath(filename)
path, ok = _joinrealpath(filename[:0], filename, {})
return abspath(path)
# Join two paths, normalizing and eliminating any symbolic links
# encountered in the second path.
def relpath(path, start=None):
"""Return a relative version of a path"""
if not path:
raise ValueError("no path specified")
path = os.fspath(path)
if isinstance(path, bytes):
curdir = b'.'
sep = b'/'
pardir = b'..'
else:
curdir = '.'
sep = '/'
pardir = '..'
if start is None:
start = curdir
else:
start = os.fspath(start)
try:
start_list = [x for x in abspath(start).split(sep) if x]
path_list = [x for x in abspath(path).split(sep) if x]
# Work out how much of the filepath is shared by start and path.
i = len(commonprefix([start_list, path_list]))
rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
if not rel_list:
return curdir
return join(*rel_list)
except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
genericpath._check_arg_types('relpath', path, start)
raise
# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.
def commonpath(paths):
"""Given a sequence of path names, returns the longest common sub-path."""
if not paths:
raise ValueError('commonpath() arg is an empty sequence')
paths = tuple(map(os.fspath, paths))
if isinstance(paths[0], bytes):
sep = b'/'
curdir = b'.'
else:
sep = '/'
curdir = '.'
try:
split_paths = [path.split(sep) for path in paths]
try:
isabs, = set(p[:1] == sep for p in paths)
except ValueError:
raise ValueError("Can't mix absolute and relative paths") from None
split_paths = [[c for c in s if c and c != curdir] for s in split_paths]
s1 = min(split_paths)
s2 = max(split_paths)
common = s1
for i, c in enumerate(s1):
if c != s2[i]:
common = s1[:i]
break
prefix = sep if isabs else sep[:0]
return prefix + sep.join(common)
except (TypeError, AttributeError):
genericpath._check_arg_types('commonpath', *paths)
raise
def _parse_args(cls, args):
# This is useful when you don't want to create an instance, just
# canonicalize some constructor arguments.
parts = []
for a in args:
if isinstance(a, PurePath):
parts += a._parts
else:
if sys.version_info >= (3, 6):
a = os.fspath(a)
else:
# duck typing for older Python versions
if hasattr(a, "__fspath__"):
a = a.__fspath__()
if isinstance(a, str):
# Force-cast str subclasses to str (issue #21127)
parts.append(str(a))
# also handle unicode for PY2 (six.text_type = unicode)
elif six.PY2 and isinstance(a, six.text_type):
# cast to str using filesystem encoding
parts.append(a.encode(sys.getfilesystemencoding()))
else:
raise TypeError(
"argument should be a str object or an os.PathLike "
"object returning str, not %r"
% type(a))
return cls._flavour.parse_parts(parts)
def isabs(s):
"""Test whether a path is absolute"""
s = os.fspath(s)
s = splitdrive(s)[1]
return len(s) > 0 and s[0] in _get_bothseps(s)
# Join two (or more) paths.
def ismount(path):
"""Test whether a path is a mount point (a drive root, the root of a
share, or a mounted volume)"""
path = os.fspath(path)
seps = _get_bothseps(path)
path = abspath(path)
root, rest = splitdrive(path)
if root and root[0] in seps:
return (not rest) or (rest in seps)
if rest in seps:
return True
if _getvolumepathname:
return path.rstrip(seps) == _getvolumepathname(path).rstrip(seps)
else:
return False
# Expand paths beginning with '~' or '~user'.
# '~' means $HOME; '~user' means that user's home directory.
# If the path doesn't begin with '~', or if the user or $HOME is unknown,
# the path is returned unchanged (leaving error reporting to whatever
# function is called with the expanded path as argument).
# See also module 'glob' for expansion of *, ? and [...] in pathnames.
# (A function should also be defined to do full *sh-style environment
# variable expansion.)
def abspath(path):
"""Return the absolute version of a path."""
path = os.fspath(path)
if not isabs(path):
if isinstance(path, bytes):
cwd = os.getcwdb()
else:
cwd = os.getcwd()
path = join(cwd, path)
return normpath(path)
def normcase(s):
"""Normalize case of pathname. Has no effect under Posix"""
s = os.fspath(s)
if not isinstance(s, (bytes, str)):
raise TypeError("normcase() argument must be str or bytes, "
"not '{}'".format(s.__class__.__name__))
return s
# Return whether a path is absolute.
# Trivial in Posix, harder on the Mac or MS-DOS.
def isabs(s):
"""Test whether a path is absolute"""
s = os.fspath(s)
sep = _get_sep(s)
return s.startswith(sep)
# Join pathnames.
# Ignore the previous parts if a part is absolute.
# Insert a '/' unless the first part is empty or already ends in '/'.
def 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. An empty last part will result in a path that
ends with a separator."""
a = os.fspath(a)
sep = _get_sep(a)
path = a
try:
if not p:
path[:0] + sep #23780: Ensure compatible data type even if p is null.
for b in map(os.fspath, p):
if b.startswith(sep):
path = b
elif not path or path.endswith(sep):
path += b
else:
path += sep + b
except (TypeError, AttributeError, BytesWarning):
genericpath._check_arg_types('join', a, *p)
raise
return path
# Split a path in head (everything up to the last '/') and tail (the
# rest). If the path ends in '/', tail will be empty. If there is no
# '/' in the path, head will be empty.
# Trailing '/'es are stripped from head unless it is the root.
