import fnmatch
import functools
import io
import ntpath
import os
import posixpath
import re
import sys
from _collections_abc import Sequence
from errno import EINVAL, ENOENT, ENOTDIR, EBADF, ELOOP
from operator import attrgetter
from stat import S_ISDIR, S_ISLNK, S_ISREG, S_ISSOCK, S_ISBLK, S_ISCHR, S_ISFIFO
from urllib.parse import quote_from_bytes as urlquote_from_bytes


supports_symlinks = True
if os.name == 'nt':
 import nt
 if sys.getwindowsversion()[:2] >= (6, 0):
 from nt import _getfinalpathname
 else:
 supports_symlinks = False
 _getfinalpathname = None
else:
 nt = None


__all__ = [
 "PurePath", "PurePosixPath", "PureWindowsPath",
 "Path", "PosixPath", "WindowsPath",
 ]

#
# Internals
#

# EBADF - guard against macOS `stat` throwing EBADF
_IGNORED_ERROS = (ENOENT, ENOTDIR, EBADF, ELOOP)

_IGNORED_WINERRORS = (
 21, # ERROR_NOT_READY - drive exists but is not accessible
 123, # ERROR_INVALID_NAME - fix for bpo-35306
 1921, # ERROR_CANT_RESOLVE_FILENAME - fix for broken symlink pointing to itself
)

def _ignore_error(exception):
 return (getattr(exception, 'errno', None) in _IGNORED_ERROS or
 getattr(exception, 'winerror', None) in _IGNORED_WINERRORS)


def _is_wildcard_pattern(pat):
 # Whether this pattern needs actual matching using fnmatch, or can
 # be looked up directly as a file.
 return "*" in pat or "?" in pat or "[" in pat


class _Flavour(object):
 """A flavour implements a particular (platform-specific) set of path
 semantics."""

 def __init__(self):
 self.join = self.sep.join

 def parse_parts(self, parts):
 parsed = []
 sep = self.sep
 altsep = self.altsep
 drv = root = ''
 it = reversed(parts)
 for part in it:
 if not part:
 continue
 if altsep:
 part = part.replace(altsep, sep)
 drv, root, rel = self.splitroot(part)
 if sep in rel:
 for x in reversed(rel.split(sep)):
 if x and x != '.':
 parsed.append(sys.intern(x))
 else:
 if rel and rel != '.':
 parsed.append(sys.intern(rel))
 if drv or root:
 if not drv:
 # If no drive is present, try to find one in the previous
 # parts. This makes the result of parsing e.g.
 # ("C:", "/", "a") reasonably intuitive.
 for part in it:
 if not part:
 continue
 if altsep:
 part = part.replace(altsep, sep)
 drv = self.splitroot(part)[0]
 if drv:
 break
 break
 if drv or root:
 parsed.append(drv + root)
 parsed.reverse()
 return drv, root, parsed

 def join_parsed_parts(self, drv, root, parts, drv2, root2, parts2):
 """
 Join the two paths represented by the respective
 (drive, root, parts) tuples. Return a new (drive, root, parts) tuple.
 """
 if root2:
 if not drv2 and drv:
 return drv, root2, [drv + root2] + parts2[1:]
 elif drv2:
 if drv2 == drv or self.casefold(drv2) == self.casefold(drv):
 # Same drive => second path is relative to the first
 return drv, root, parts + parts2[1:]
 else:
 # Second path is non-anchored (common case)
 return drv, root, parts + parts2
 return drv2, root2, parts2


class _WindowsFlavour(_Flavour):
 # Reference for Windows paths can be found at
 # http://msdn.microsoft.com/en-us/library/aa365247%28v=vs.85%29.aspx

 sep = '\\'
 altsep = '/'
 has_drv = True
 pathmod = ntpath

 is_supported = (os.name == 'nt')

 drive_letters = set('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ')
 ext_namespace_prefix = '\\\\?\\'

 reserved_names = (
 {'CON', 'PRN', 'AUX', 'NUL'} |
 {'COM%d' % i for i in range(1, 10)} |
 {'LPT%d' % i for i in range(1, 10)}
 )

 # Interesting findings about extended paths:
 # - '\\?\c:\a', '//?/c:\a' and '//?/c:/a' are all supported
 # but '\\?\c:/a' is not
 # - extended paths are always absolute; "relative" extended paths will
 # fail.

 def splitroot(self, part, sep=sep):
 first = part[0:1]
 second = part[1:2]
 if (second == sep and first == sep):
 # XXX extended paths should also disable the collapsing of "."
 # components (according to MSDN docs).
 prefix, part = self._split_extended_path(part)
 first = part[0:1]
 second = part[1:2]
 else:
 prefix = ''
 third = part[2:3]
 if (second == sep and first == sep and third != sep):
 # is a UNC path:
 # vvvvvvvvvvvvvvvvvvvvv root
 # \\machine\mountpoint\directory\etc\...
 # directory ^^^^^^^^^^^^^^
 index = part.find(sep, 2)
 if index != -1:
 index2 = part.find(sep, index + 1)
 # a UNC path can't have two slashes in a row
 # (after the initial two)
 if index2 != index + 1:
 if index2 == -1:
 index2 = len(part)
 if prefix:
 return prefix + part[1:index2], sep, part[index2+1:]
 else:
 return part[:index2], sep, part[index2+1:]
 drv = root = ''
 if second == ':' and first in self.drive_letters:
 drv = part[:2]
 part = part[2:]
 first = third
 if first == sep:
 root = first
 part = part.lstrip(sep)
 return prefix + drv, root, part

 def casefold(self, s):
 return s.lower()

 def casefold_parts(self, parts):
 return [p.lower() for p in parts]

 def compile_pattern(self, pattern):
 return re.compile(fnmatch.translate(pattern), re.IGNORECASE).fullmatch

 def resolve(self, path, strict=False):
 s = str(path)
 if not s:
 return os.getcwd()
 previous_s = None
 if _getfinalpathname is not None:
 if strict:
 return self._ext_to_normal(_getfinalpathname(s))
 else:
 tail_parts = [] # End of the path after the first one not found
 while True:
 try:
 s = self._ext_to_normal(_getfinalpathname(s))
 except FileNotFoundError:
 previous_s = s
 s, tail = os.path.split(s)
 tail_parts.append(tail)
 if previous_s == s:
 return path
 else:
 return os.path.join(s, *reversed(tail_parts))
 # Means fallback on absolute
 return None

 def _split_extended_path(self, s, ext_prefix=ext_namespace_prefix):
 prefix = ''
 if s.startswith(ext_prefix):
 prefix = s[:4]
 s = s[4:]
 if s.startswith('UNC\\'):
 prefix += s[:3]
 s = '\\' + s[3:]
 return prefix, s

 def _ext_to_normal(self, s):
 # Turn back an extended path into a normal DOS-like path
 return self._split_extended_path(s)[1]

 def is_reserved(self, parts):
 # NOTE: the rules for reserved names seem somewhat complicated
 # (e.g. r"..\NUL" is reserved but not r"foo\NUL").
 # We err on the side of caution and return True for paths which are
 # not considered reserved by Windows.
 if not parts:
 return False
 if parts[0].startswith('\\\\'):
 # UNC paths are never reserved
 return False
 return parts[-1].partition('.')[0].upper() in self.reserved_names

 def make_uri(self, path):
 # Under Windows, file URIs use the UTF-8 encoding.
 drive = path.drive
 if len(drive) == 2 and drive[1] == ':':
 # It's a path on a local drive => 'file:///c:/a/b'
 rest = path.as_posix()[2:].lstrip('/')
 return 'file:///%s/%s' % (
 drive, urlquote_from_bytes(rest.encode('utf-8')))
 else:
 # It's a path on a network drive => 'file://host/share/a/b'
 return 'file:' + urlquote_from_bytes(path.as_posix().encode('utf-8'))

 def gethomedir(self, username):
 if 'USERPROFILE' in os.environ:
 userhome = os.environ['USERPROFILE']
 elif 'HOMEPATH' in os.environ:
 try:
 drv = os.environ['HOMEDRIVE']
 except KeyError:
 drv = ''
 userhome = drv + os.environ['HOMEPATH']
 else:
 raise RuntimeError("Can't determine home directory")

 if username:
 # Try to guess user home directory. By default all users
 # directories are located in the same place and are named by
 # corresponding usernames. If current user home directory points
 # to nonstandard place, this guess is likely wrong.
 if os.environ['USERNAME'] != username:
 drv, root, parts = self.parse_parts((userhome,))
 if parts[-1] != os.environ['USERNAME']:
 raise RuntimeError("Can't determine home directory "
 "for %r" % username)
 parts[-1] = username
 if drv or root:
 userhome = drv + root + self.join(parts[1:])
 else:
 userhome = self.join(parts)
 return userhome

class _PosixFlavour(_Flavour):
 sep = '/'
 altsep = ''
 has_drv = False
 pathmod = posixpath

 is_supported = (os.name != 'nt')

 def splitroot(self, part, sep=sep):
 if part and part[0] == sep:
 stripped_part = part.lstrip(sep)
 # According to POSIX path resolution:
 # http://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap04.html#tag_04_11
 # "A pathname that begins with two successive slashes may be
 # interpreted in an implementation-defined manner, although more
 # than two leading slashes shall be treated as a single slash".
 if len(part) - len(stripped_part) == 2:
 return '', sep * 2, stripped_part
 else:
 return '', sep, stripped_part
 else:
 return '', '', part

 def casefold(self, s):
 return s

 def casefold_parts(self, parts):
 return parts

 def compile_pattern(self, pattern):
 return re.compile(fnmatch.translate(pattern)).fullmatch

 def resolve(self, path, strict=False):
 sep = self.sep
 accessor = path._accessor
 seen = {}
 def _resolve(path, rest):
 if rest.startswith(sep):
 path = ''

 for name in rest.split(sep):
 if not name or name == '.':
 # current dir
 continue
 if name == '..':
 # parent dir
 path, _, _ = path.rpartition(sep)
 continue
 if path.endswith(sep):
 newpath = path + name
 else:
 newpath = path + sep + name
 if newpath in seen:
 # Already seen this path
 path = seen[newpath]
 if path is not None:
 # use cached value
 continue
 # The symlink is not resolved, so we must have a symlink loop.
 raise RuntimeError("Symlink loop from %r" % newpath)
 # Resolve the symbolic link
 try:
 target = accessor.readlink(newpath)
 except OSError as e:
 if e.errno != EINVAL and strict:
 raise
 # Not a symlink, or non-strict mode. We just leave the path
 # untouched.
 path = newpath
 else:
 seen[newpath] = None # not resolved symlink
 path = _resolve(path, target)
 seen[newpath] = path # resolved symlink

 return path
 # NOTE: according to POSIX, getcwd() cannot contain path components
 # which are symlinks.
 base = '' if path.is_absolute() else os.getcwd()
 return _resolve(base, str(path)) or sep

 def is_reserved(self, parts):
 return False

 def make_uri(self, path):
 # We represent the path using the local filesystem encoding,
 # for portability to other applications.
 bpath = bytes(path)
 return 'file://' + urlquote_from_bytes(bpath)

 def gethomedir(self, username):
 if not username:
 try:
 return os.environ['HOME']
 except KeyError:
 import pwd
 return pwd.getpwuid(os.getuid()).pw_dir
 else:
 import pwd
 try:
 return pwd.getpwnam(username).pw_dir
 except KeyError:
 raise RuntimeError("Can't determine home directory "
 "for %r" % username)


_windows_flavour = _WindowsFlavour()
_posix_flavour = _PosixFlavour()


class _Accessor:
 """An accessor implements a particular (system-specific or not) way of
 accessing paths on the filesystem."""


class _NormalAccessor(_Accessor):

 stat = os.stat

 lstat = os.lstat

 open = os.open

 listdir = os.listdir

 scandir = os.scandir

 chmod = os.chmod

 if hasattr(os, "lchmod"):
 lchmod = os.lchmod
 else:
 def lchmod(self, pathobj, mode):
 raise NotImplementedError("lchmod() not available on this system")

 mkdir = os.mkdir

 unlink = os.unlink

 if hasattr(os, "link"):
 link_to = os.link
 else:
 @staticmethod
 def link_to(self, target):
 raise NotImplementedError("os.link() not available on this system")

 rmdir = os.rmdir

 rename = os.rename

 replace = os.replace

 if nt:
 if supports_symlinks:
 symlink = os.symlink
 else:
 def symlink(a, b, target_is_directory):
 raise NotImplementedError("symlink() not available on this system")
 else:
 # Under POSIX, os.symlink() takes two args
 @staticmethod
 def symlink(a, b, target_is_directory):
 return os.symlink(a, b)

 utime = os.utime

 # Helper for resolve()
 def readlink(self, path):
 return os.readlink(path)


_normal_accessor = _NormalAccessor()


#
# Globbing helpers
#

def _make_selector(pattern_parts, flavour):
 pat = pattern_parts[0]
 child_parts = pattern_parts[1:]
 if pat == '**':
 cls = _RecursiveWildcardSelector
 elif '**' in pat:
 raise ValueError("Invalid pattern: '**' can only be an entire path component")
 elif _is_wildcard_pattern(pat):
 cls = _WildcardSelector
 else:
 cls = _PreciseSelector
 return cls(pat, child_parts, flavour)

if hasattr(functools, "lru_cache"):
 _make_selector = functools.lru_cache()(_make_selector)


class _Selector:
 """A selector matches a specific glob pattern part against the children
 of a given path."""

 def __init__(self, child_parts, flavour):
 self.child_parts = child_parts
 if child_parts:
 self.successor = _make_selector(child_parts, flavour)
 self.dironly = True
 else:
 self.successor = _TerminatingSelector()
 self.dironly = False

 def select_from(self, parent_path):
 """Iterate over all child paths of `parent_path` matched by this
 selector. This can contain parent_path itself."""
 path_cls = type(parent_path)
 is_dir = path_cls.is_dir
 exists = path_cls.exists
 scandir = parent_path._accessor.scandir
 if not is_dir(parent_path):
 return iter([])
 return self._select_from(parent_path, is_dir, exists, scandir)


class _TerminatingSelector:

 def _select_from(self, parent_path, is_dir, exists, scandir):
 yield parent_path


class _PreciseSelector(_Selector):

 def __init__(self, name, child_parts, flavour):
 self.name = name
 _Selector.__init__(self, child_parts, flavour)

 def _select_from(self, parent_path, is_dir, exists, scandir):
 try:
 path = parent_path._make_child_relpath(self.name)
 if (is_dir if self.dironly else exists)(path):
 for p in self.successor._select_from(path, is_dir, exists, scandir):
 yield p
 except PermissionError:
 return


class _WildcardSelector(_Selector):

 def __init__(self, pat, child_parts, flavour):
 self.match = flavour.compile_pattern(pat)
 _Selector.__init__(self, child_parts, flavour)

 def _select_from(self, parent_path, is_dir, exists, scandir):
 try:
 with scandir(parent_path) as scandir_it:
 entries = list(scandir_it)
 for entry in entries:
 if self.dironly:
 try:
 # "entry.is_dir()" can raise PermissionError
 # in some cases (see bpo-38894), which is not
 # among the errors ignored by _ignore_error()
 if not entry.is_dir():
 continue
 except OSError as e:
 if not _ignore_error(e):
 raise
 continue
 name = entry.name
 if self.match(name):
 path = parent_path._make_child_relpath(name)
 for p in self.successor._select_from(path, is_dir, exists, scandir):
 yield p
 except PermissionError:
 return


class _RecursiveWildcardSelector(_Selector):

 def __init__(self, pat, child_parts, flavour):
 _Selector.__init__(self, child_parts, flavour)

 def _iterate_directories(self, parent_path, is_dir, scandir):
 yield parent_path
 try:
 with scandir(parent_path) as scandir_it:
 entries = list(scandir_it)
 for entry in entries:
 entry_is_dir = False
 try:
 entry_is_dir = entry.is_dir()
 except OSError as e:
 if not _ignore_error(e):
 raise
 if entry_is_dir and not entry.is_symlink():
 path = parent_path._make_child_relpath(entry.name)
 for p in self._iterate_directories(path, is_dir, scandir):
 yield p
 except PermissionError:
 return

 def _select_from(self, parent_path, is_dir, exists, scandir):
 try:
 yielded = set()
 try:
 successor_select = self.successor._select_from
 for starting_point in self._iterate_directories(parent_path, is_dir, scandir):
 for p in successor_select(starting_point, is_dir, exists, scandir):
 if p not in yielded:
 yield p
 yielded.add(p)
 finally:
 yielded.clear()
 except PermissionError:
 return


#
# Public API
#

class _PathParents(Sequence):
 """This object provides sequence-like access to the logical ancestors
 of a path. Don't try to construct it yourself."""
 __slots__ = ('_pathcls', '_drv', '_root', '_parts')

 def __init__(self, path):
 # We don't store the instance to avoid reference cycles
 self._pathcls = type(path)
 self._drv = path._drv
 self._root = path._root
 self._parts = path._parts

 def __len__(self):
 if self._drv or self._root:
 return len(self._parts) - 1
 else:
 return len(self._parts)

 def __getitem__(self, idx):
 if idx < 0 or idx >= len(self):
 raise IndexError(idx)
 return self._pathcls._from_parsed_parts(self._drv, self._root,
 self._parts[:-idx - 1])

 def __repr__(self):
 return "<{}.parents>".format(self._pathcls.__name__)


class PurePath(object):
 """Base class for manipulating paths without I/O.

 PurePath represents a filesystem path and offers operations which
 don't imply any actual filesystem I/O. Depending on your system,
 instantiating a PurePath will return either a PurePosixPath or a
 PureWindowsPath object. You can also instantiate either of these classes
 directly, regardless of your system.
 """
 __slots__ = (
 '_drv', '_root', '_parts',
 '_str', '_hash', '_pparts', '_cached_cparts',
 )

 def __new__(cls, *args):
 """Construct a PurePath from one or several strings and or existing
 PurePath objects. The strings and path objects are combined so as
 to yield a canonicalized path, which is incorporated into the
 new PurePath object.
 """
 if cls is PurePath:
 cls = PureWindowsPath if os.name == 'nt' else PurePosixPath
 return cls._from_parts(args)

 def __reduce__(self):
 # Using the parts tuple helps share interned path parts
 # when pickling related paths.
 return (self.__class__, tuple(self._parts))

 @classmethod
 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:
 a = os.fspath(a)
 if isinstance(a, str):
 # Force-cast str subclasses to str (issue #21127)
 parts.append(str(a))
 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)

 @classmethod
 def _from_parts(cls, args, init=True):
 # We need to call _parse_args on the instance, so as to get the
 # right flavour.
 self = object.__new__(cls)
 drv, root, parts = self._parse_args(args)
 self._drv = drv
 self._root = root
 self._parts = parts
 if init:
 self._init()
 return self

 @classmethod
 def _from_parsed_parts(cls, drv, root, parts, init=True):
 self = object.__new__(cls)
 self._drv = drv
 self._root = root
 self._parts = parts
 if init:
 self._init()
 return self

 @classmethod
 def _format_parsed_parts(cls, drv, root, parts):
 if drv or root:
 return drv + root + cls._flavour.join(parts[1:])
 else:
 return cls._flavour.join(parts)

 def _init(self):
 # Overridden in concrete Path
 pass

 def _make_child(self, args):
 drv, root, parts = self._parse_args(args)
 drv, root, parts = self._flavour.join_parsed_parts(
 self._drv, self._root, self._parts, drv, root, parts)
 return self._from_parsed_parts(drv, root, parts)

 def __str__(self):
 """Return the string representation of the path, suitable for
 passing to system calls."""
 try:
 return self._str
 except AttributeError:
 self._str = self._format_parsed_parts(self._drv, self._root,
 self._parts) or '.'
 return self._str

 def __fspath__(self):
 return str(self)

 def as_posix(self):
 """Return the string representation of the path with forward (/)
 slashes."""
 f = self._flavour
 return str(self).replace(f.sep, '/')

 def __bytes__(self):
 """Return the bytes representation of the path. This is only
 recommended to use under Unix."""
 return os.fsencode(self)

 def __repr__(self):
 return "{}({!r})".format(self.__class__.__name__, self.as_posix())

 def as_uri(self):
 """Return the path as a 'file' URI."""
 if not self.is_absolute():
 raise ValueError("relative path can't be expressed as a file URI")
 return self._flavour.make_uri(self)

 @property
 def _cparts(self):
 # Cached casefolded parts, for hashing and comparison
 try:
 return self._cached_cparts
 except AttributeError:
 self._cached_cparts = self._flavour.casefold_parts(self._parts)
 return self._cached_cparts

 def __eq__(self, other):
 if not isinstance(other, PurePath):
 return NotImplemented
 return self._cparts == other._cparts and self._flavour is other._flavour

 def __hash__(self):
 try:
 return self._hash
 except AttributeError:
 self._hash = hash(tuple(self._cparts))
 return self._hash

 def __lt__(self, other):
 if not isinstance(other, PurePath) or self._flavour is not other._flavour:
 return NotImplemented
 return self._cparts < other._cparts

 def __le__(self, other):
 if not isinstance(other, PurePath) or self._flavour is not other._flavour:
 return NotImplemented
 return self._cparts <= other._cparts

 def __gt__(self, other):
 if not isinstance(other, PurePath) or self._flavour is not other._flavour:
 return NotImplemented
 return self._cparts > other._cparts

 def __ge__(self, other):
 if not isinstance(other, PurePath) or self._flavour is not other._flavour:
 return NotImplemented
 return self._cparts >= other._cparts

 drive = property(attrgetter('_drv'),
 doc="""The drive prefix (letter or UNC path), if any.""")

 root = property(attrgetter('_root'),
 doc="""The root of the path, if any.""")

 @property
 def anchor(self):
 """The concatenation of the drive and root, or ''."""
 anchor = self._drv + self._root
 return anchor

 @property
 def name(self):
 """The final path component, if any."""
 parts = self._parts
 if len(parts) == (1 if (self._drv or self._root) else 0):
 return ''
 return parts[-1]

 @property
 def suffix(self):
 """
 The final component's last suffix, if any.

 This includes the leading period. For example: '.txt'
 """
 name = self.name
 i = name.rfind('.')
 if 0 < i < len(name) - 1:
 return name[i:]
 else:
 return ''

 @property
 def suffixes(self):
 """
 A list of the final component's suffixes, if any.

 These include the leading periods. For example: ['.tar', '.gz']
 """
 name = self.name
 if name.endswith('.'):
 return []
 name = name.lstrip('.')
 return ['.' + suffix for suffix in name.split('.')[1:]]

 @property
 def stem(self):
 """The final path component, minus its last suffix."""
 name = self.name
 i = name.rfind('.')
 if 0 < i < len(name) - 1:
 return name[:i]
 else:
 return name

 def with_name(self, name):
 """Return a new path with the file name changed."""
 if not self.name:
 raise ValueError("%r has an empty name" % (self,))
 drv, root, parts = self._flavour.parse_parts((name,))
 if (not name or name[-1] in [self._flavour.sep, self._flavour.altsep]
 or drv or root or len(parts) != 1):
 raise ValueError("Invalid name %r" % (name))
 return self._from_parsed_parts(self._drv, self._root,
 self._parts[:-1] + [name])

 def with_suffix(self, suffix):
 """Return a new path with the file suffix changed. If the path
 has no suffix, add given suffix. If the given suffix is an empty
 string, remove the suffix from the path.
 """
 f = self._flavour
 if f.sep in suffix or f.altsep and f.altsep in suffix:
 raise ValueError("Invalid suffix %r" % (suffix,))
 if suffix and not suffix.startswith('.') or suffix == '.':
 raise ValueError("Invalid suffix %r" % (suffix))
 name = self.name
 if not name:
 raise ValueError("%r has an empty name" % (self,))
 old_suffix = self.suffix
 if not old_suffix:
 name = name + suffix
 else:
 name = name[:-len(old_suffix)] + suffix
 return self._from_parsed_parts(self._drv, self._root,
 self._parts[:-1] + [name])

 def relative_to(self, *other):
 """Return the relative path to another path identified by the passed
 arguments. If the operation is not possible (because this is not
 a subpath of the other path), raise ValueError.
 """
 # For the purpose of this method, drive and root are considered
 # separate parts, i.e.:
 # Path('c:/').relative_to('c:') gives Path('/')
 # Path('c:/').relative_to('/') raise ValueError
 if not other:
 raise TypeError("need at least one argument")
 parts = self._parts
 drv = self._drv
 root = self._root
 if root:
 abs_parts = [drv, root] + parts[1:]
 else:
 abs_parts = parts
 to_drv, to_root, to_parts = self._parse_args(other)
 if to_root:
 to_abs_parts = [to_drv, to_root] + to_parts[1:]
 else:
 to_abs_parts = to_parts
 n = len(to_abs_parts)
 cf = self._flavour.casefold_parts
 if (root or drv) if n == 0 else cf(abs_parts[:n]) != cf(to_abs_parts):
 formatted = self._format_parsed_parts(to_drv, to_root, to_parts)
 raise ValueError("{!r} does not start with {!r}"
 .format(str(self), str(formatted)))
 return self._from_parsed_parts('', root if n == 1 else '',
 abs_parts[n:])

 @property
 def parts(self):
 """An object providing sequence-like access to the
 components in the filesystem path."""
 # We cache the tuple to avoid building a new one each time .parts
 # is accessed. XXX is this necessary?
 try:
 return self._pparts
 except AttributeError:
 self._pparts = tuple(self._parts)
 return self._pparts

 def joinpath(self, *args):
 """Combine this path with one or several arguments, and return a
 new path representing either a subpath (if all arguments are relative
 paths) or a totally different path (if one of the arguments is
 anchored).
 """
 return self._make_child(args)

 def __truediv__(self, key):
 try:
 return self._make_child((key,))
 except TypeError:
 return NotImplemented

 def __rtruediv__(self, key):
 try:
 return self._from_parts([key] + self._parts)
 except TypeError:
 return NotImplemented

 @property
 def parent(self):
 """The logical parent of the path."""
 drv = self._drv
 root = self._root
 parts = self._parts
 if len(parts) == 1 and (drv or root):
 return self
 return self._from_parsed_parts(drv, root, parts[:-1])

 @property
 def parents(self):
 """A sequence of this path's logical parents."""
 return _PathParents(self)

 def is_absolute(self):
 """True if the path is absolute (has both a root and, if applicable,
 a drive)."""
 if not self._root:
 return False
 return not self._flavour.has_drv or bool(self._drv)

 def is_reserved(self):
 """Return True if the path contains one of the special names reserved
 by the system, if any."""
 return self._flavour.is_reserved(self._parts)

 def match(self, path_pattern):
 """
 Return True if this path matches the given pattern.
 """
 cf = self._flavour.casefold
 path_pattern = cf(path_pattern)
 drv, root, pat_parts = self._flavour.parse_parts((path_pattern,))
 if not pat_parts:
 raise ValueError("empty pattern")
 if drv and drv != cf(self._drv):
 return False
 if root and root != cf(self._root):
 return False
 parts = self._cparts
 if drv or root:
 if len(pat_parts) != len(parts):
 return False
 pat_parts = pat_parts[1:]
 elif len(pat_parts) > len(parts):
 return False
 for part, pat in zip(reversed(parts), reversed(pat_parts)):
 if not fnmatch.fnmatchcase(part, pat):
 return False
 return True

# Can't subclass os.PathLike from PurePath and keep the constructor
# optimizations in PurePath._parse_args().
os.PathLike.register(PurePath)


class PurePosixPath(PurePath):
 """PurePath subclass for non-Windows systems.

 On a POSIX system, instantiating a PurePath should return this object.
 However, you can also instantiate it directly on any system.
 """
 _flavour = _posix_flavour
 __slots__ = ()


class PureWindowsPath(PurePath):
 """PurePath subclass for Windows systems.

 On a Windows system, instantiating a PurePath should return this object.
 However, you can also instantiate it directly on any system.
 """
 _flavour = _windows_flavour
 __slots__ = ()


# Filesystem-accessing classes


class Path(PurePath):
 """PurePath subclass that can make system calls.

 Path represents a filesystem path but unlike PurePath, also offers
 methods to do system calls on path objects. Depending on your system,
 instantiating a Path will return either a PosixPath or a WindowsPath
 object. You can also instantiate a PosixPath or WindowsPath directly,
 but cannot instantiate a WindowsPath on a POSIX system or vice versa.
 """
 __slots__ = (
 '_accessor',
 '_closed',
 )

 def __new__(cls, *args, **kwargs):
 if cls is Path:
 cls = WindowsPath if os.name == 'nt' else PosixPath
 self = cls._from_parts(args, init=False)
 if not self._flavour.is_supported:
 raise NotImplementedError("cannot instantiate %r on your system"
 % (cls.__name__,))
 self._init()
 return self

 def _init(self,
 # Private non-constructor arguments
 template=None,
 ):
 self._closed = False
 if template is not None:
 self._accessor = template._accessor
 else:
 self._accessor = _normal_accessor

 def _make_child_relpath(self, part):
 # This is an optimization used for dir walking. `part` must be
 # a single part relative to this path.
 parts = self._parts + [part]
 return self._from_parsed_parts(self._drv, self._root, parts)

 def __enter__(self):
 if self._closed:
 self._raise_closed()
 return self

 def __exit__(self, t, v, tb):
 self._closed = True

 def _raise_closed(self):
 raise ValueError("I/O operation on closed path")

 def _opener(self, name, flags, mode=0o666):
 # A stub for the opener argument to built-in open()
 return self._accessor.open(self, flags, mode)

 def _raw_open(self, flags, mode=0o777):
 """
 Open the file pointed by this path and return a file descriptor,
 as os.open() does.
 """
 if self._closed:
 self._raise_closed()
 return self._accessor.open(self, flags, mode)

 # Public API

 @classmethod
 def cwd(cls):
 """Return a new path pointing to the current working directory
 (as returned by os.getcwd()).
 """
 return cls(os.getcwd())

 @classmethod
 def home(cls):
 """Return a new path pointing to the user's home directory (as
 returned by os.path.expanduser('~')).
 """
 return cls(cls()._flavour.gethomedir(None))

 def samefile(self, other_path):
 """Return whether other_path is the same or not as this file
 (as returned by os.path.samefile()).
 """
 st = self.stat()
 try:
 other_st = other_path.stat()
 except AttributeError:
 other_st = os.stat(other_path)
 return os.path.samestat(st, other_st)

 def iterdir(self):
 """Iterate over the files in this directory. Does not yield any
 result for the special paths '.' and '..'.
 """
 if self._closed:
 self._raise_closed()
 for name in self._accessor.listdir(self):
 if name in {'.', '..'}:
 # Yielding a path object for these makes little sense
 continue
 yield self._make_child_relpath(name)
 if self._closed:
 self._raise_closed()

 def glob(self, pattern):
 """Iterate over this subtree and yield all existing files (of any
 kind, including directories) matching the given relative pattern.
 """
 if not pattern:
 raise ValueError("Unacceptable pattern: {!r}".format(pattern))
 drv, root, pattern_parts = self._flavour.parse_parts((pattern,))
 if drv or root:
 raise NotImplementedError("Non-relative patterns are unsupported")
 selector = _make_selector(tuple(pattern_parts), self._flavour)
 for p in selector.select_from(self):
 yield p

 def rglob(self, pattern):
 """Recursively yield all existing files (of any kind, including
 directories) matching the given relative pattern, anywhere in
 this subtree.
 """
 drv, root, pattern_parts = self._flavour.parse_parts((pattern,))
 if drv or root:
 raise NotImplementedError("Non-relative patterns are unsupported")
 selector = _make_selector(("**",) + tuple(pattern_parts), self._flavour)
 for p in selector.select_from(self):
 yield p

 def absolute(self):
 """Return an absolute version of this path. This function works
 even if the path doesn't point to anything.

 No normalization is done, i.e. all '.' and '..' will be kept along.
 Use resolve() to get the canonical path to a file.
 """
 # XXX untested yet!
 if self._closed:
 self._raise_closed()
 if self.is_absolute():
 return self
 # FIXME this must defer to the specific flavour (and, under Windows,
 # use nt._getfullpathname())
 obj = self._from_parts([os.getcwd()] + self._parts, init=False)
 obj._init(template=self)
 return obj

 def resolve(self, strict=False):
 """
 Make the path absolute, resolving all symlinks on the way and also
 normalizing it (for example turning slashes into backslashes under
 Windows).
 """
 if self._closed:
 self._raise_closed()
 s = self._flavour.resolve(self, strict=strict)
 if s is None:
 # No symlink resolution => for consistency, raise an error if
 # the path doesn't exist or is forbidden
 self.stat()
 s = str(self.absolute())
 # Now we have no symlinks in the path, it's safe to normalize it.
 normed = self._flavour.pathmod.normpath(s)
 obj = self._from_parts((normed,), init=False)
 obj._init(template=self)
 return obj

 def stat(self):
 """
 Return the result of the stat() system call on this path, like
 os.stat() does.
 """
 return self._accessor.stat(self)

 def owner(self):
 """
 Return the login name of the file owner.
 """
 import pwd
 return pwd.getpwuid(self.stat().st_uid).pw_name

 def group(self):
 """
 Return the group name of the file gid.
 """
 import grp
 return grp.getgrgid(self.stat().st_gid).gr_name

 def open(self, mode='r', buffering=-1, encoding=None,
 errors=None, newline=None):
 """
 Open the file pointed by this path and return a file object, as
 the built-in open() function does.
 """
 if self._closed:
 self._raise_closed()
 return io.open(self, mode, buffering, encoding, errors, newline,
 opener=self._opener)

 def read_bytes(self):
 """
 Open the file in bytes mode, read it, and close the file.
 """
 with self.open(mode='rb') as f:
 return f.read()

 def read_text(self, encoding=None, errors=None):
 """
 Open the file in text mode, read it, and close the file.
 """
 with self.open(mode='r', encoding=encoding, errors=errors) as f:
 return f.read()

 def write_bytes(self, data):
 """
 Open the file in bytes mode, write to it, and close the file.
 """
 # type-check for the buffer interface before truncating the file
 view = memoryview(data)
 with self.open(mode='wb') as f:
 return f.write(view)

 def write_text(self, data, encoding=None, errors=None):
 """
 Open the file in text mode, write to it, and close the file.
 """
 if not isinstance(data, str):
 raise TypeError('data must be str, not %s' %
 data.__class__.__name__)
 with self.open(mode='w', encoding=encoding, errors=errors) as f:
 return f.write(data)

 def touch(self, mode=0o666, exist_ok=True):
 """
 Create this file with the given access mode, if it doesn't exist.
 """
 if self._closed:
 self._raise_closed()
 if exist_ok:
 # First try to bump modification time
 # Implementation note: GNU touch uses the UTIME_NOW option of
 # the utimensat() / futimens() functions.
 try:
 self._accessor.utime(self, None)
 except OSError:
 # Avoid exception chaining
 pass
 else:
 return
 flags = os.O_CREAT | os.O_WRONLY
 if not exist_ok:
 flags |= os.O_EXCL
 fd = self._raw_open(flags, mode)
 os.close(fd)

 def mkdir(self, mode=0o777, parents=False, exist_ok=False):
 """
 Create a new directory at this given path.
 """
 if self._closed:
 self._raise_closed()
 try:
 self._accessor.mkdir(self, mode)
 except FileNotFoundError:
 if not parents or self.parent == self:
 raise
 self.parent.mkdir(parents=True, exist_ok=True)
 self.mkdir(mode, parents=False, exist_ok=exist_ok)
 except OSError:
 # Cannot rely on checking for EEXIST, since the operating system
 # could give priority to other errors like EACCES or EROFS
 if not exist_ok or not self.is_dir():
 raise

 def chmod(self, mode):
 """
 Change the permissions of the path, like os.chmod().
 """
 if self._closed:
 self._raise_closed()
 self._accessor.chmod(self, mode)

 def lchmod(self, mode):
 """
 Like chmod(), except if the path points to a symlink, the symlink's
 permissions are changed, rather than its target's.
 """
 if self._closed:
 self._raise_closed()
 self._accessor.lchmod(self, mode)

 def unlink(self, missing_ok=False):
 """
 Remove this file or link.
 If the path is a directory, use rmdir() instead.
 """
 if self._closed:
 self._raise_closed()
 try:
 self._accessor.unlink(self)
 except FileNotFoundError:
 if not missing_ok:
 raise

 def rmdir(self):
 """
 Remove this directory. The directory must be empty.
 """
 if self._closed:
 self._raise_closed()
 self._accessor.rmdir(self)

 def lstat(self):
 """
 Like stat(), except if the path points to a symlink, the symlink's
 status information is returned, rather than its target's.
 """
 if self._closed:
 self._raise_closed()
 return self._accessor.lstat(self)

 def rename(self, target):
 """
 Rename this path to the target path.

 The target path may be absolute or relative. Relative paths are
 interpreted relative to the current working directory, *not* the
 directory of the Path object.

 Returns the new Path instance pointing to the target path.
 """
 if self._closed:
 self._raise_closed()
 self._accessor.rename(self, target)
 return self.__class__(target)

 def replace(self, target):
 """
 Rename this path to the target path, overwriting if that path exists.

 The target path may be absolute or relative. Relative paths are
 interpreted relative to the current working directory, *not* the
 directory of the Path object.

 Returns the new Path instance pointing to the target path.
 """
 if self._closed:
 self._raise_closed()
 self._accessor.replace(self, target)
 return self.__class__(target)

 def symlink_to(self, target, target_is_directory=False):
 """
 Make this path a symlink pointing to the target path.
 Note the order of arguments (link, target) is the reverse of os.symlink.
 """
 if self._closed:
 self._raise_closed()
 self._accessor.symlink(target, self, target_is_directory)

 def link_to(self, target):
 """
 Make the target path a hard link pointing to this path.

 Note this function does not make this path a hard link to *target*,
 despite the implication of the function and argument names. The order
 of arguments (target, link) is the reverse of Path.symlink_to, but
 matches that of os.link.

 """
 if self._closed:
 self._raise_closed()
 self._accessor.link_to(self, target)

 # Convenience functions for querying the stat results

 def exists(self):
 """
 Whether this path exists.
 """
 try:
 self.stat()
 except OSError as e:
 if not _ignore_error(e):
 raise
 return False
 except ValueError:
 # Non-encodable path
 return False
 return True

 def is_dir(self):
 """
 Whether this path is a directory.
 """
 try:
 return S_ISDIR(self.stat().st_mode)
 except OSError as e:
 if not _ignore_error(e):
 raise
 # Path doesn't exist or is a broken symlink
 # (see https://bitbucket.org/pitrou/pathlib/issue/12/)
 return False
 except ValueError:
 # Non-encodable path
 return False

 def is_file(self):
 """
 Whether this path is a regular file (also True for symlinks pointing
 to regular files).
 """
 try:
 return S_ISREG(self.stat().st_mode)
 except OSError as e:
 if not _ignore_error(e):
 raise
 # Path doesn't exist or is a broken symlink
 # (see https://bitbucket.org/pitrou/pathlib/issue/12/)
 return False
 except ValueError:
 # Non-encodable path
 return False

 def is_mount(self):
 """
 Check if this path is a POSIX mount point
 """
 # Need to exist and be a dir
 if not self.exists() or not self.is_dir():
 return False

 parent = Path(self.parent)
 try:
 parent_dev = parent.stat().st_dev
 except OSError:
 return False

 dev = self.stat().st_dev
 if dev != parent_dev:
 return True
 ino = self.stat().st_ino
 parent_ino = parent.stat().st_ino
 return ino == parent_ino

 def is_symlink(self):
 """
 Whether this path is a symbolic link.
 """
 try:
 return S_ISLNK(self.lstat().st_mode)
 except OSError as e:
 if not _ignore_error(e):
 raise
 # Path doesn't exist
 return False
 except ValueError:
 # Non-encodable path
 return False

 def is_block_device(self):
 """
 Whether this path is a block device.
 """
 try:
 return S_ISBLK(self.stat().st_mode)
 except OSError as e:
 if not _ignore_error(e):
 raise
 # Path doesn't exist or is a broken symlink
 # (see https://bitbucket.org/pitrou/pathlib/issue/12/)
 return False
 except ValueError:
 # Non-encodable path
 return False

 def is_char_device(self):
 """
 Whether this path is a character device.
 """
 try:
 return S_ISCHR(self.stat().st_mode)
 except OSError as e:
 if not _ignore_error(e):
 raise
 # Path doesn't exist or is a broken symlink
 # (see https://bitbucket.org/pitrou/pathlib/issue/12/)
 return False
 except ValueError:
 # Non-encodable path
 return False

 def is_fifo(self):
 """
 Whether this path is a FIFO.
 """
 try:
 return S_ISFIFO(self.stat().st_mode)
 except OSError as e:
 if not _ignore_error(e):
 raise
 # Path doesn't exist or is a broken symlink
 # (see https://bitbucket.org/pitrou/pathlib/issue/12/)
 return False
 except ValueError:
 # Non-encodable path
 return False

 def is_socket(self):
 """
 Whether this path is a socket.
 """
 try:
 return S_ISSOCK(self.stat().st_mode)
 except OSError as e:
 if not _ignore_error(e):
 raise
 # Path doesn't exist or is a broken symlink
 # (see https://bitbucket.org/pitrou/pathlib/issue/12/)
 return False
 except ValueError:
 # Non-encodable path
 return False

 def expanduser(self):
 """ Return a new path with expanded ~ and ~user constructs
 (as returned by os.path.expanduser)
 """
 if (not (self._drv or self._root) and
 self._parts and self._parts[0][:1] == '~'):
 homedir = self._flavour.gethomedir(self._parts[0][1:])
 return self._from_parts([homedir] + self._parts[1:])

 return self


class PosixPath(Path, PurePosixPath):
 """Path subclass for non-Windows systems.

 On a POSIX system, instantiating a Path should return this object.
 """
 __slots__ = ()

class WindowsPath(Path, PureWindowsPath):
 """Path subclass for Windows systems.

 On a Windows system, instantiating a Path should return this object.
 """
 __slots__ = ()

 def owner(self):
 raise NotImplementedError("Path.owner() is unsupported on this system")

 def group(self):
 raise NotImplementedError("Path.group() is unsupported on this system")

 def is_mount(self):
 raise NotImplementedError("Path.is_mount() is unsupported on this system")