"""

Abstract base classes for rich path objects.

This module is published as a PyPI package called "pathlib-abc".

This module is also a *PRIVATE* part of the Python standard library, where

it's developed alongside pathlib. If it finds success and maturity as a PyPI

package, it could become a public part of the standard library.

Two base classes are defined here -- PurePathBase and PathBase -- that

resemble pathlib's PurePath and Path respectively.

"""

import functools

import posixpath

from glob import _Globber, _no_recurse_symlinks

from stat import S_ISDIR, S_ISLNK, S_ISREG, S_ISSOCK, S_ISBLK, S_ISCHR, S_ISFIFO

__all__ = ["UnsupportedOperation"]

@functools.cache

def _is_case_sensitive(parser):

return parser.normcase('Aa') == 'Aa'

class UnsupportedOperation(NotImplementedError):

"""An exception that is raised when an unsupported operation is called on

a path object.

"""

pass

class ParserBase:

"""Base class for path parsers, which do low-level path manipulation.

Path parsers provide a subset of the os.path API, specifically those

functions needed to provide PurePathBase functionality. Each PurePathBase

subclass references its path parser via a 'parser' class attribute.

Every method in this base class raises an UnsupportedOperation exception.

"""

@classmethod

def _unsupported_msg(cls, attribute):

return f"{cls.__name__}.{attribute} is unsupported"

@property

def sep(self):

"""The character used to separate path components."""

raise UnsupportedOperation(self._unsupported_msg('sep'))

def join(self, path, *paths):

"""Join path segments."""

raise UnsupportedOperation(self._unsupported_msg('join()'))

def split(self, path):

"""Split the path into a pair (head, tail), where *head* is everything

before the final path separator, and *tail* is everything after.

Either part may be empty.

"""

raise UnsupportedOperation(self._unsupported_msg('split()'))

def splitdrive(self, path):

"""Split the path into a 2-item tuple (drive, tail), where *drive* is

a device name or mount point, and *tail* is everything after the

drive. Either part may be empty."""

raise UnsupportedOperation(self._unsupported_msg('splitdrive()'))

def splitext(self, path):

"""Split the path into a pair (root, ext), where *ext* is empty or

begins with a begins with a period and contains at most one period,

and *root* is everything before the extension."""

raise UnsupportedOperation(self._unsupported_msg('splitext()'))

def normcase(self, path):

"""Normalize the case of the path."""

raise UnsupportedOperation(self._unsupported_msg('normcase()'))

def isabs(self, path):

"""Returns whether the path is absolute, i.e. unaffected by the

current directory or drive."""

raise UnsupportedOperation(self._unsupported_msg('isabs()'))

class PurePathBase:

"""Base class for pure path objects.

This class *does not* provide several magic methods that are defined in

its subclass PurePath. They are: __fspath__, __bytes__, __reduce__,

__hash__, __eq__, __lt__, __le__, __gt__, __ge__. Its initializer and path

joining methods accept only strings, not os.PathLike objects more broadly.

"""

__slots__ = (

# The `_raw_path` slot store a joined string path. This is set in the

# `__init__()` method.

'_raw_path',

# The '_resolving' slot stores a boolean indicating whether the path

# is being processed by `PathBase.resolve()`. This prevents duplicate

# work from occurring when `resolve()` calls `stat()` or `readlink()`.

'_resolving',

)

parser = ParserBase()

_globber = _Globber

def __init__(self, path, *paths):

self._raw_path = self.parser.join(path, *paths) if paths else path

if not isinstance(self._raw_path, str):

raise TypeError(

f"path should be a str, not {type(self._raw_path).__name__!r}")

self._resolving = False

def with_segments(self, *pathsegments):

"""Construct a new path object from any number of path-like objects.

Subclasses may override this method to customize how new path objects

are created from methods like `iterdir()`.

"""

return type(self)(*pathsegments)

def __str__(self):

"""Return the string representation of the path, suitable for

passing to system calls."""

return self._raw_path

def as_posix(self):

"""Return the string representation of the path with forward (/)

slashes."""

return str(self).replace(self.parser.sep, '/')

@property

def drive(self):

"""The drive prefix (letter or UNC path), if any."""

return self.parser.splitdrive(self.anchor)[0]

@property

def root(self):

"""The root of the path, if any."""

return self.parser.splitdrive(self.anchor)[1]

@property

def anchor(self):

"""The concatenation of the drive and root, or ''."""

return self._stack[0]

@property

def name(self):

"""The final path component, if any."""

return self.parser.split(self._raw_path)[1]

@property

def suffix(self):

"""

The final component's last suffix, if any.

This includes the leading period. For example: '.txt'

"""

return self.parser.splitext(self.name)[1]

@property

def suffixes(self):

"""

A list of the final component's suffixes, if any.

These include the leading periods. For example: ['.tar', '.gz']

"""

split = self.parser.splitext

stem, suffix = split(self.name)

suffixes = []

while suffix:

suffixes.append(suffix)

stem, suffix = split(stem)

return suffixes[::-1]

@property

def stem(self):

"""The final path component, minus its last suffix."""

return self.parser.splitext(self.name)[0]

def with_name(self, name):

"""Return a new path with the file name changed."""

split = self.parser.split

if split(name)[0]:

raise ValueError(f"Invalid name {name!r}")

return self.with_segments(split(self._raw_path)[0], name)

def with_stem(self, stem):

"""Return a new path with the stem changed."""

suffix = self.suffix

if not suffix:

return self.with_name(stem)

elif not stem:

# If the suffix is non-empty, we can't make the stem empty.

raise ValueError(f"{self!r} has a non-empty suffix")

else:

return self.with_name(stem + suffix)

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.

"""

stem = self.stem

if not stem:

# If the stem is empty, we can't make the suffix non-empty.

raise ValueError(f"{self!r} has an empty name")

elif suffix and not suffix.startswith('.'):

raise ValueError(f"Invalid suffix {suffix!r}")

else:

return self.with_name(stem + suffix)

def relative_to(self, other, *, walk_up=False):

"""Return the relative path to another path identified by the passed

arguments. If the operation is not possible (because this is not

related to the other path), raise ValueError.

The *walk_up* parameter controls whether `..` may be used to resolve

the path.

"""

if not isinstance(other, PurePathBase):

other = self.with_segments(other)

anchor0, parts0 = self._stack

anchor1, parts1 = other._stack

if anchor0 != anchor1:

raise ValueError(f"{self._raw_path!r} and {other._raw_path!r} have different anchors")

while parts0 and parts1 and parts0[-1] == parts1[-1]:

parts0.pop()

parts1.pop()

for part in parts1:

if not part or part == '.':

pass

elif not walk_up:

raise ValueError(f"{self._raw_path!r} is not in the subpath of {other._raw_path!r}")

elif part == '..':

raise ValueError(f"'..' segment in {other._raw_path!r} cannot be walked")

else:

parts0.append('..')

return self.with_segments('', *reversed(parts0))

def is_relative_to(self, other):

"""Return True if the path is relative to another path or False.

"""

if not isinstance(other, PurePathBase):

other = self.with_segments(other)

anchor0, parts0 = self._stack

anchor1, parts1 = other._stack

if anchor0 != anchor1:

return False

while parts0 and parts1 and parts0[-1] == parts1[-1]:

parts0.pop()

parts1.pop()

for part in parts1:

if part and part != '.':

return False

return True

@property

def parts(self):

"""An object providing sequence-like access to the

components in the filesystem path."""

anchor, parts = self._stack

if anchor:

parts.append(anchor)

return tuple(reversed(parts))

def joinpath(self, *pathsegments):

"""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.with_segments(self._raw_path, *pathsegments)

def __truediv__(self, key):

try:

return self.with_segments(self._raw_path, key)

except TypeError:

return NotImplemented

def __rtruediv__(self, key):

try:

return self.with_segments(key, self._raw_path)

except TypeError:

return NotImplemented

@property

def _stack(self):

"""

Split the path into a 2-tuple (anchor, parts), where *anchor* is the

uppermost parent of the path (equivalent to path.parents[-1]), and

*parts* is a reversed list of parts following the anchor.

"""

split = self.parser.split

path = self._raw_path

parent, name = split(path)

names = []

while path != parent:

names.append(name)

path = parent

parent, name = split(path)

return path, names

@property

def parent(self):

"""The logical parent of the path."""

path = self._raw_path

parent = self.parser.split(path)[0]

if path != parent:

parent = self.with_segments(parent)

parent._resolving = self._resolving

return parent

return self

@property

def parents(self):

"""A sequence of this path's logical parents."""

split = self.parser.split

path = self._raw_path

parent = split(path)[0]

parents = []

while path != parent:

parents.append(self.with_segments(parent))

path = parent

parent = split(path)[0]

return tuple(parents)

def is_absolute(self):

"""True if the path is absolute (has both a root and, if applicable,

a drive)."""

return self.parser.isabs(self._raw_path)

@property

def _pattern_str(self):

"""The path expressed as a string, for use in pattern-matching."""

return str(self)

def match(self, path_pattern, *, case_sensitive=None):

"""

Return True if this path matches the given pattern. If the pattern is

relative, matching is done from the right; otherwise, the entire path

is matched. The recursive wildcard '**' is *not* supported by this

method.

"""

if not isinstance(path_pattern, PurePathBase):

path_pattern = self.with_segments(path_pattern)

if case_sensitive is None:

case_sensitive = _is_case_sensitive(self.parser)

sep = path_pattern.parser.sep

path_parts = self.parts[::-1]

pattern_parts = path_pattern.parts[::-1]

if not pattern_parts:

raise ValueError("empty pattern")

if len(path_parts) < len(pattern_parts):

return False

if len(path_parts) > len(pattern_parts) and path_pattern.anchor:

return False

globber = self._globber(sep, case_sensitive)

for path_part, pattern_part in zip(path_parts, pattern_parts):

match = globber.compile(pattern_part)

if match(path_part) is None:

return False

return True

def full_match(self, pattern, *, case_sensitive=None):

"""

Return True if this path matches the given glob-style pattern. The

pattern is matched against the entire path.

"""

if not isinstance(pattern, PurePathBase):

pattern = self.with_segments(pattern)

if case_sensitive is None:

case_sensitive = _is_case_sensitive(self.parser)

globber = self._globber(pattern.parser.sep, case_sensitive, recursive=True)

match = globber.compile(pattern._pattern_str)

return match(self._pattern_str) is not None

class PathBase(PurePathBase):

"""Base class for concrete path objects.

This class provides dummy implementations for many methods that derived

classes can override selectively; the default implementations raise

UnsupportedOperation. The most basic methods, such as stat() and open(),

directly raise UnsupportedOperation; these basic methods are called by

other methods such as is_dir() and read_text().

The Path class derives this class to implement local filesystem paths.

Users may derive their own classes to implement virtual filesystem paths,

such as paths in archive files or on remote storage systems.

"""

__slots__ = ()

# Maximum number of symlinks to follow in resolve()

_max_symlinks = 40

@classmethod

def _unsupported_msg(cls, attribute):

return f"{cls.__name__}.{attribute} is unsupported"

def stat(self, *, follow_symlinks=True):

"""

Return the result of the stat() system call on this path, like

os.stat() does.

"""

raise UnsupportedOperation(self._unsupported_msg('stat()'))

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.

"""

return self.stat(follow_symlinks=False)

# Convenience functions for querying the stat results

def exists(self, *, follow_symlinks=True):

"""

Whether this path exists.

This method normally follows symlinks; to check whether a symlink exists,

add the argument follow_symlinks=False.

"""

try:

self.stat(follow_symlinks=follow_symlinks)

except (OSError, ValueError):

return False

return True

def is_dir(self, *, follow_symlinks=True):

"""

Whether this path is a directory.

"""

try:

return S_ISDIR(self.stat(follow_symlinks=follow_symlinks).st_mode)

except (OSError, ValueError):

return False

def is_file(self, *, follow_symlinks=True):

"""

Whether this path is a regular file (also True for symlinks pointing

to regular files).

"""

try:

return S_ISREG(self.stat(follow_symlinks=follow_symlinks).st_mode)

except (OSError, ValueError):

return False

def is_mount(self):

"""

Check if this path is a mount point

"""

# Need to exist and be a dir

if not self.exists() or not self.is_dir():

return False

try:

parent_dev = self.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 = self.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, ValueError):

return False

def is_junction(self):

"""

Whether this path is a junction.

"""

# Junctions are a Windows-only feature, not present in POSIX nor the

# majority of virtual filesystems. There is no cross-platform idiom

# to check for junctions (using stat().st_mode).

return False

def is_block_device(self):

"""

Whether this path is a block device.

"""

try:

return S_ISBLK(self.stat().st_mode)

except (OSError, ValueError):

return False

def is_char_device(self):

"""

Whether this path is a character device.

"""

try:

return S_ISCHR(self.stat().st_mode)

except (OSError, ValueError):

return False

def is_fifo(self):

"""

Whether this path is a FIFO.

"""

try:

return S_ISFIFO(self.stat().st_mode)

except (OSError, ValueError):

return False

def is_socket(self):

"""

Whether this path is a socket.

"""

try:

return S_ISSOCK(self.stat().st_mode)

except (OSError, ValueError):

return False

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 = self.with_segments(other_path).stat()

return (st.st_ino == other_st.st_ino and

st.st_dev == other_st.st_dev)

def open(self, mode='r', buffering=-1, encoding=None,

errors=None, newline=None):

"""

Open the file pointed to by this path and return a file object, as

the built-in open() function does.

"""

raise UnsupportedOperation(self._unsupported_msg('open()'))

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, newline=None):

"""

Open the file in text mode, read it, and close the file.

"""

with self.open(mode='r', encoding=encoding, errors=errors, newline=newline) 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, newline=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, newline=newline) as f:

return f.write(data)

def iterdir(self):

"""Yield path objects of the directory contents.

The children are yielded in arbitrary order, and the

special entries '.' and '..' are not included.

"""

raise UnsupportedOperation(self._unsupported_msg('iterdir()'))

def _glob_selector(self, parts, case_sensitive, recurse_symlinks):

if case_sensitive is None:

case_sensitive = _is_case_sensitive(self.parser)

case_pedantic = False

else:

# The user has expressed a case sensitivity choice, but we don't

# know the case sensitivity of the underlying filesystem, so we

# must use scandir() for everything, including non-wildcard parts.

case_pedantic = True

recursive = True if recurse_symlinks else _no_recurse_symlinks

globber = self._globber(self.parser.sep, case_sensitive, case_pedantic, recursive)

return globber.selector(parts)

def glob(self, pattern, *, case_sensitive=None, recurse_symlinks=True):

"""Iterate over this subtree and yield all existing files (of any

kind, including directories) matching the given relative pattern.

"""

if not isinstance(pattern, PurePathBase):

pattern = self.with_segments(pattern)

anchor, parts = pattern._stack

if anchor:

raise NotImplementedError("Non-relative patterns are unsupported")

select = self._glob_selector(parts, case_sensitive, recurse_symlinks)

return select(self)

def rglob(self, pattern, *, case_sensitive=None, recurse_symlinks=True):

"""Recursively yield all existing files (of any kind, including

directories) matching the given relative pattern, anywhere in

this subtree.

"""

if not isinstance(pattern, PurePathBase):

pattern = self.with_segments(pattern)

pattern = '**' / pattern

return self.glob(pattern, case_sensitive=case_sensitive, recurse_symlinks=recurse_symlinks)

def walk(self, top_down=True, on_error=None, follow_symlinks=False):

"""Walk the directory tree from this directory, similar to os.walk()."""

paths = [self]

while paths:

path = paths.pop()

if isinstance(path, tuple):

yield path

continue

dirnames = []

filenames = []

if not top_down:

paths.append((path, dirnames, filenames))

try:

for child in path.iterdir():

try:

if child.is_dir(follow_symlinks=follow_symlinks):

if not top_down:

paths.append(child)

dirnames.append(child.name)

else:

filenames.append(child.name)

except OSError:

filenames.append(child.name)

except OSError as error:

if on_error is not None:

on_error(error)

if not top_down:

while not isinstance(paths.pop(), tuple):

pass

continue

if top_down:

yield path, dirnames, filenames

paths += [path.joinpath(d) for d in reversed(dirnames)]

def absolute(self):

"""Return an absolute version of this path

No normalization or symlink resolution is performed.

Use resolve() to resolve symlinks and remove '..' segments.

"""

raise UnsupportedOperation(self._unsupported_msg('absolute()'))

@classmethod

def cwd(cls):

"""Return a new path pointing to the current working directory."""

# We call 'absolute()' rather than using 'os.getcwd()' directly to

# enable users to replace the implementation of 'absolute()' in a

# subclass and benefit from the new behaviour here. This works because

# os.path.abspath('.') == os.getcwd().

return cls('').absolute()

def expanduser(self):

""" Return a new path with expanded ~ and ~user constructs

(as returned by os.path.expanduser)

"""

raise UnsupportedOperation(self._unsupported_msg('expanduser()'))

@classmethod

def home(cls):

"""Return a new path pointing to expanduser('~').

"""

return cls("~").expanduser()

def readlink(self):

"""

Return the path to which the symbolic link points.

"""

raise UnsupportedOperation(self._unsupported_msg('readlink()'))

readlink._supported = False

def resolve(self, strict=False):

"""

Make the path absolute, resolving all symlinks on the way and also

normalizing it.

"""

if self._resolving:

return self

def getcwd():

return str(self.with_segments().absolute())

if strict or getattr(self.readlink, '_supported', True):

def lstat(path_str):

path = self.with_segments(path_str)

path._resolving = True

return path.lstat()

def readlink(path_str):

path = self.with_segments(path_str)

path._resolving = True

return str(path.readlink())

else:

# If the user has *not* overridden the `readlink()` method, then

# symlinks are unsupported and (in non-strict mode) we can improve

# performance by not calling `path.lstat()`.

def skip(path_str):

# This exception will be internally consumed by `_realpath()`.

raise OSError("Operation skipped.")

lstat = readlink = skip

return self.with_segments(posixpath._realpath(

str(self), strict, self.parser.sep,

getcwd=getcwd, lstat=lstat, readlink=readlink,

maxlinks=self._max_symlinks))

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.

"""

raise UnsupportedOperation(self._unsupported_msg('symlink_to()'))

def hardlink_to(self, target):

"""

Make this path a hard link pointing to the same file as *target*.

Note the order of arguments (self, target) is the reverse of os.link's.

"""

raise UnsupportedOperation(self._unsupported_msg('hardlink_to()'))

def touch(self, mode=0o666, exist_ok=True):

"""

Create this file with the given access mode, if it doesn't exist.

"""

raise UnsupportedOperation(self._unsupported_msg('touch()'))

def mkdir(self, mode=0o777, parents=False, exist_ok=False):

"""

Create a new directory at this given path.

"""

raise UnsupportedOperation(self._unsupported_msg('mkdir()'))

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.

"""

raise UnsupportedOperation(self._unsupported_msg('rename()'))

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.

"""

raise UnsupportedOperation(self._unsupported_msg('replace()'))

def chmod(self, mode, *, follow_symlinks=True):

"""

Change the permissions of the path, like os.chmod().

"""

raise UnsupportedOperation(self._unsupported_msg('chmod()'))

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.

"""

self.chmod(mode, follow_symlinks=False)

def unlink(self, missing_ok=False):

"""

Remove this file or link.

If the path is a directory, use rmdir() instead.

"""

raise UnsupportedOperation(self._unsupported_msg('unlink()'))

def rmdir(self):

"""

Remove this directory. The directory must be empty.

"""

raise UnsupportedOperation(self._unsupported_msg('rmdir()'))

def owner(self, *, follow_symlinks=True):

"""

Return the login name of the file owner.

"""

raise UnsupportedOperation(self._unsupported_msg('owner()'))

def group(self, *, follow_symlinks=True):

"""

Return the group name of the file gid.

"""

raise UnsupportedOperation(self._unsupported_msg('group()'))

@classmethod

def from_uri(cls, uri):

"""Return a new path from the given 'file' URI."""

raise UnsupportedOperation(cls._unsupported_msg('from_uri()'))

def as_uri(self):

"""Return the path as a URI."""

raise UnsupportedOperation(self._unsupported_msg('as_uri()'))