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diff --git a/contrib/tools/python3/Lib/ntpath.py b/contrib/tools/python3/Lib/ntpath.py
new file mode 100644
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+++ b/contrib/tools/python3/Lib/ntpath.py
@@ -0,0 +1,897 @@
+# Module 'ntpath' -- common operations on WinNT/Win95 pathnames
+"""Common pathname manipulations, WindowsNT/95 version.
+
+Instead of importing this module directly, import os and refer to this
+module as os.path.
+"""
+
+# strings representing various path-related bits and pieces
+# These are primarily for export; internally, they are hardcoded.
+# Should be set before imports for resolving cyclic dependency.
+curdir = '.'
+pardir = '..'
+extsep = '.'
+sep = '\\'
+pathsep = ';'
+altsep = '/'
+defpath = '.;C:\\bin'
+devnull = 'nul'
+
+import os
+import sys
+import stat
+import genericpath
+from genericpath import *
+
+
+__all__ = ["normcase","isabs","join","splitdrive","splitroot","split","splitext",
+           "basename","dirname","commonprefix","getsize","getmtime",
+           "getatime","getctime", "islink","exists","lexists","isdir","isfile",
+           "ismount", "expanduser","expandvars","normpath","abspath",
+           "curdir","pardir","sep","pathsep","defpath","altsep",
+           "extsep","devnull","realpath","supports_unicode_filenames","relpath",
+           "samefile", "sameopenfile", "samestat", "commonpath", "isjunction"]
+
+def _get_bothseps(path):
+    if isinstance(path, bytes):
+        return b'\\/'
+    else:
+        return '\\/'
+
+# Normalize the case of a pathname and map slashes to backslashes.
+# Other normalizations (such as optimizing '../' away) are not done
+# (this is done by normpath).
+
+try:
+    from _winapi import (
+        LCMapStringEx as _LCMapStringEx,
+        LOCALE_NAME_INVARIANT as _LOCALE_NAME_INVARIANT,
+        LCMAP_LOWERCASE as _LCMAP_LOWERCASE)
+
+    def normcase(s):
+        """Normalize case of pathname.
+
+        Makes all characters lowercase and all slashes into backslashes.
+        """
+        s = os.fspath(s)
+        if not s:
+            return s
+        if isinstance(s, bytes):
+            encoding = sys.getfilesystemencoding()
+            s = s.decode(encoding, 'surrogateescape').replace('/', '\\')
+            s = _LCMapStringEx(_LOCALE_NAME_INVARIANT,
+                               _LCMAP_LOWERCASE, s)
+            return s.encode(encoding, 'surrogateescape')
+        else:
+            return _LCMapStringEx(_LOCALE_NAME_INVARIANT,
+                                  _LCMAP_LOWERCASE,
+                                  s.replace('/', '\\'))
+except ImportError:
+    def normcase(s):
+        """Normalize case of pathname.
+
+        Makes all characters lowercase and all slashes into backslashes.
+        """
+        s = os.fspath(s)
+        if isinstance(s, bytes):
+            return os.fsencode(os.fsdecode(s).replace('/', '\\').lower())
+        return s.replace('/', '\\').lower()
+
+
+# Return whether a path is absolute.
+# Trivial in Posix, harder on Windows.
+# For Windows it is absolute if it starts with a slash or backslash (current
+# volume), or if a pathname after the volume-letter-and-colon or UNC-resource
+# starts with a slash or backslash.
+
+def isabs(s):
+    """Test whether a path is absolute"""
+    s = os.fspath(s)
+    if isinstance(s, bytes):
+        sep = b'\\'
+        altsep = b'/'
+        colon_sep = b':\\'
+    else:
+        sep = '\\'
+        altsep = '/'
+        colon_sep = ':\\'
+    s = s[:3].replace(altsep, sep)
+    # Absolute: UNC, device, and paths with a drive and root.
+    # LEGACY BUG: isabs("/x") should be false since the path has no drive.
+    if s.startswith(sep) or s.startswith(colon_sep, 1):
+        return True
+    return False
+
+
+# Join two (or more) paths.
+def join(path, *paths):
+    path = os.fspath(path)
+    if isinstance(path, bytes):
+        sep = b'\\'
+        seps = b'\\/'
+        colon = b':'
+    else:
+        sep = '\\'
+        seps = '\\/'
+        colon = ':'
+    try:
+        if not paths:
+            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
+        result_drive, result_root, result_path = splitroot(path)
+        for p in map(os.fspath, paths):
+            p_drive, p_root, p_path = splitroot(p)
+            if p_root:
+                # Second path is absolute
+                if p_drive or not result_drive:
+                    result_drive = p_drive
+                result_root = p_root
+                result_path = p_path
+                continue
+            elif p_drive and p_drive != result_drive:
+                if p_drive.lower() != result_drive.lower():
+                    # Different drives => ignore the first path entirely
+                    result_drive = p_drive
+                    result_root = p_root
+                    result_path = p_path
+                    continue
+                # Same drive in different case
+                result_drive = p_drive
+            # Second path is relative to the first
+            if result_path and result_path[-1] not in seps:
+                result_path = result_path + sep
+            result_path = result_path + p_path
+        ## add separator between UNC and non-absolute path
+        if (result_path and not result_root and
+            result_drive and result_drive[-1:] not in colon + seps):
+            return result_drive + sep + result_path
+        return result_drive + result_root + result_path
+    except (TypeError, AttributeError, BytesWarning):
+        genericpath._check_arg_types('join', path, *paths)
+        raise
+
+
+# Split a path in a drive specification (a drive letter followed by a
+# colon) and the path specification.
+# It is always true that drivespec + pathspec == p
+def splitdrive(p):
+    """Split a pathname into drive/UNC sharepoint and relative path specifiers.
+    Returns a 2-tuple (drive_or_unc, path); either part may be empty.
+
+    If you assign
+        result = splitdrive(p)
+    It is always true that:
+        result[0] + result[1] == p
+
+    If the path contained a drive letter, drive_or_unc will contain everything
+    up to and including the colon.  e.g. splitdrive("c:/dir") returns ("c:", "/dir")
+
+    If the path contained a UNC path, the drive_or_unc will contain the host name
+    and share up to but not including the fourth directory separator character.
+    e.g. splitdrive("//host/computer/dir") returns ("//host/computer", "/dir")
+
+    Paths cannot contain both a drive letter and a UNC path.
+
+    """
+    drive, root, tail = splitroot(p)
+    return drive, root + tail
+
+
+def splitroot(p):
+    """Split a pathname into drive, root and tail. The drive is defined
+    exactly as in splitdrive(). On Windows, the root may be a single path
+    separator or an empty string. The tail contains anything after the root.
+    For example:
+
+        splitroot('//server/share/') == ('//server/share', '/', '')
+        splitroot('C:/Users/Barney') == ('C:', '/', 'Users/Barney')
+        splitroot('C:///spam///ham') == ('C:', '/', '//spam///ham')
+        splitroot('Windows/notepad') == ('', '', 'Windows/notepad')
+    """
+    p = os.fspath(p)
+    if isinstance(p, bytes):
+        sep = b'\\'
+        altsep = b'/'
+        colon = b':'
+        unc_prefix = b'\\\\?\\UNC\\'
+        empty = b''
+    else:
+        sep = '\\'
+        altsep = '/'
+        colon = ':'
+        unc_prefix = '\\\\?\\UNC\\'
+        empty = ''
+    normp = p.replace(altsep, sep)
+    if normp[:1] == sep:
+        if normp[1:2] == sep:
+            # UNC drives, e.g. \\server\share or \\?\UNC\server\share
+            # Device drives, e.g. \\.\device or \\?\device
+            start = 8 if normp[:8].upper() == unc_prefix else 2
+            index = normp.find(sep, start)
+            if index == -1:
+                return p, empty, empty
+            index2 = normp.find(sep, index + 1)
+            if index2 == -1:
+                return p, empty, empty
+            return p[:index2], p[index2:index2 + 1], p[index2 + 1:]
+        else:
+            # Relative path with root, e.g. \Windows
+            return empty, p[:1], p[1:]
+    elif normp[1:2] == colon:
+        if normp[2:3] == sep:
+            # Absolute drive-letter path, e.g. X:\Windows
+            return p[:2], p[2:3], p[3:]
+        else:
+            # Relative path with drive, e.g. X:Windows
+            return p[:2], empty, p[2:]
+    else:
+        # Relative path, e.g. Windows
+        return empty, empty, p
+
+
+# Split a path in head (everything up to the last '/') and tail (the
+# rest).  After the trailing '/' is stripped, the invariant
+# join(head, tail) == p holds.
+# The resulting head won't end in '/' unless it is the root.
+
+def split(p):
+    """Split a pathname.
+
+    Return tuple (head, tail) where tail is everything after the final slash.
+    Either part may be empty."""
+    p = os.fspath(p)
+    seps = _get_bothseps(p)
+    d, r, p = splitroot(p)
+    # set i to index beyond p's last slash
+    i = len(p)
+    while i and p[i-1] not in seps:
+        i -= 1
+    head, tail = p[:i], p[i:]  # now tail has no slashes
+    return d + r + head.rstrip(seps), tail
+
+
+# Split a path in root and extension.
+# The extension is everything starting at the last dot in the last
+# pathname component; the root is everything before that.
+# It is always true that root + ext == p.
+
+def splitext(p):
+    p = os.fspath(p)
+    if isinstance(p, bytes):
+        return genericpath._splitext(p, b'\\', b'/', b'.')
+    else:
+        return genericpath._splitext(p, '\\', '/', '.')
+splitext.__doc__ = genericpath._splitext.__doc__
+
+
+# Return the tail (basename) part of a path.
+
+def basename(p):
+    """Returns the final component of a pathname"""
+    return split(p)[1]
+
+
+# Return the head (dirname) part of a path.
+
+def dirname(p):
+    """Returns the directory component of a pathname"""
+    return split(p)[0]
+
+
+# Is a path a junction?
+
+if hasattr(os.stat_result, 'st_reparse_tag'):
+    def isjunction(path):
+        """Test whether a path is a junction"""
+        try:
+            st = os.lstat(path)
+        except (OSError, ValueError, AttributeError):
+            return False
+        return bool(st.st_reparse_tag == stat.IO_REPARSE_TAG_MOUNT_POINT)
+else:
+    def isjunction(path):
+        """Test whether a path is a junction"""
+        os.fspath(path)
+        return False
+
+
+# Being true for dangling symbolic links is also useful.
+
+def lexists(path):
+    """Test whether a path exists.  Returns True for broken symbolic links"""
+    try:
+        st = os.lstat(path)
+    except (OSError, ValueError):
+        return False
+    return True
+
+# Is a path a mount point?
+# Any drive letter root (eg c:\)
+# Any share UNC (eg \\server\share)
+# Any volume mounted on a filesystem folder
+#
+# No one method detects all three situations. Historically we've lexically
+# detected drive letter roots and share UNCs. The canonical approach to
+# detecting mounted volumes (querying the reparse tag) fails for the most
+# common case: drive letter roots. The alternative which uses GetVolumePathName
+# fails if the drive letter is the result of a SUBST.
+try:
+    from nt import _getvolumepathname
+except ImportError:
+    _getvolumepathname = None
+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)
+    drive, root, rest = splitroot(path)
+    if drive and drive[0] in seps:
+        return not rest
+    if root and not rest:
+        return True
+
+    if _getvolumepathname:
+        x = path.rstrip(seps)
+        y =_getvolumepathname(path).rstrip(seps)
+        return x.casefold() == y.casefold()
+    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 expanduser(path):
+    """Expand ~ and ~user constructs.
+
+    If user or $HOME is unknown, do nothing."""
+    path = os.fspath(path)
+    if isinstance(path, bytes):
+        tilde = b'~'
+    else:
+        tilde = '~'
+    if not path.startswith(tilde):
+        return path
+    i, n = 1, len(path)
+    while i < n and path[i] not in _get_bothseps(path):
+        i += 1
+
+    if 'USERPROFILE' in os.environ:
+        userhome = os.environ['USERPROFILE']
+    elif not 'HOMEPATH' in os.environ:
+        return path
+    else:
+        try:
+            drive = os.environ['HOMEDRIVE']
+        except KeyError:
+            drive = ''
+        userhome = join(drive, os.environ['HOMEPATH'])
+
+    if i != 1: #~user
+        target_user = path[1:i]
+        if isinstance(target_user, bytes):
+            target_user = os.fsdecode(target_user)
+        current_user = os.environ.get('USERNAME')
+
+        if target_user != current_user:
+            # Try to guess user home directory.  By default all user
+            # profile directories are located in the same place and are
+            # named by corresponding usernames.  If userhome isn't a
+            # normal profile directory, this guess is likely wrong,
+            # so we bail out.
+            if current_user != basename(userhome):
+                return path
+            userhome = join(dirname(userhome), target_user)
+
+    if isinstance(path, bytes):
+        userhome = os.fsencode(userhome)
+
+    return userhome + path[i:]
+
+
+# Expand paths containing shell variable substitutions.
+# The following rules apply:
+#       - no expansion within single quotes
+#       - '$$' is translated into '$'
+#       - '%%' is translated into '%' if '%%' are not seen in %var1%%var2%
+#       - ${varname} is accepted.
+#       - $varname is accepted.
+#       - %varname% is accepted.
+#       - varnames can be made out of letters, digits and the characters '_-'
+#         (though is not verified in the ${varname} and %varname% cases)
+# XXX With COMMAND.COM you can use any characters in a variable name,
+# XXX except '^|<>='.
+
+def expandvars(path):
+    """Expand shell variables of the forms $var, ${var} and %var%.
+
+    Unknown variables are left unchanged."""
+    path = os.fspath(path)
+    if isinstance(path, bytes):
+        if b'$' not in path and b'%' not in path:
+            return path
+        import string
+        varchars = bytes(string.ascii_letters + string.digits + '_-', 'ascii')
+        quote = b'\''
+        percent = b'%'
+        brace = b'{'
+        rbrace = b'}'
+        dollar = b'$'
+        environ = getattr(os, 'environb', None)
+    else:
+        if '$' not in path and '%' not in path:
+            return path
+        import string
+        varchars = string.ascii_letters + string.digits + '_-'
+        quote = '\''
+        percent = '%'
+        brace = '{'
+        rbrace = '}'
+        dollar = '$'
+        environ = os.environ
+    res = path[:0]
+    index = 0
+    pathlen = len(path)
+    while index < pathlen:
+        c = path[index:index+1]
+        if c == quote:   # no expansion within single quotes
+            path = path[index + 1:]
+            pathlen = len(path)
+            try:
+                index = path.index(c)
+                res += c + path[:index + 1]
+            except ValueError:
+                res += c + path
+                index = pathlen - 1
+        elif c == percent:  # variable or '%'
+            if path[index + 1:index + 2] == percent:
+                res += c
+                index += 1
+            else:
+                path = path[index+1:]
+                pathlen = len(path)
+                try:
+                    index = path.index(percent)
+                except ValueError:
+                    res += percent + path
+                    index = pathlen - 1
+                else:
+                    var = path[:index]
+                    try:
+                        if environ is None:
+                            value = os.fsencode(os.environ[os.fsdecode(var)])
+                        else:
+                            value = environ[var]
+                    except KeyError:
+                        value = percent + var + percent
+                    res += value
+        elif c == dollar:  # variable or '$$'
+            if path[index + 1:index + 2] == dollar:
+                res += c
+                index += 1
+            elif path[index + 1:index + 2] == brace:
+                path = path[index+2:]
+                pathlen = len(path)
+                try:
+                    index = path.index(rbrace)
+                except ValueError:
+                    res += dollar + brace + path
+                    index = pathlen - 1
+                else:
+                    var = path[:index]
+                    try:
+                        if environ is None:
+                            value = os.fsencode(os.environ[os.fsdecode(var)])
+                        else:
+                            value = environ[var]
+                    except KeyError:
+                        value = dollar + brace + var + rbrace
+                    res += value
+            else:
+                var = path[:0]
+                index += 1
+                c = path[index:index + 1]
+                while c and c in varchars:
+                    var += c
+                    index += 1
+                    c = path[index:index + 1]
+                try:
+                    if environ is None:
+                        value = os.fsencode(os.environ[os.fsdecode(var)])
+                    else:
+                        value = environ[var]
+                except KeyError:
+                    value = dollar + var
+                res += value
+                if c:
+                    index -= 1
+        else:
+            res += c
+        index += 1
+    return res
+
+
+# Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A\B.
+# Previously, this function also truncated pathnames to 8+3 format,
+# but as this module is called "ntpath", that's obviously wrong!
+try:
+    from nt import _path_normpath
+
+except ImportError:
+    def normpath(path):
+        """Normalize path, eliminating double slashes, etc."""
+        path = os.fspath(path)
+        if isinstance(path, bytes):
+            sep = b'\\'
+            altsep = b'/'
+            curdir = b'.'
+            pardir = b'..'
+        else:
+            sep = '\\'
+            altsep = '/'
+            curdir = '.'
+            pardir = '..'
+        path = path.replace(altsep, sep)
+        drive, root, path = splitroot(path)
+        prefix = drive + root
+        comps = path.split(sep)
+        i = 0
+        while i < len(comps):
+            if not comps[i] or comps[i] == curdir:
+                del comps[i]
+            elif comps[i] == pardir:
+                if i > 0 and comps[i-1] != pardir:
+                    del comps[i-1:i+1]
+                    i -= 1
+                elif i == 0 and root:
+                    del comps[i]
+                else:
+                    i += 1
+            else:
+                i += 1
+        # If the path is now empty, substitute '.'
+        if not prefix and not comps:
+            comps.append(curdir)
+        return prefix + sep.join(comps)
+
+else:
+    def normpath(path):
+        """Normalize path, eliminating double slashes, etc."""
+        path = os.fspath(path)
+        if isinstance(path, bytes):
+            return os.fsencode(_path_normpath(os.fsdecode(path))) or b"."
+        return _path_normpath(path) or "."
+
+
+def _abspath_fallback(path):
+    """Return the absolute version of a path as a fallback function in case
+    `nt._getfullpathname` is not available or raises OSError. See bpo-31047 for
+    more.
+
+    """
+
+    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 an absolute path.
+try:
+    from nt import _getfullpathname
+
+except ImportError: # not running on Windows - mock up something sensible
+    abspath = _abspath_fallback
+
+else:  # use native Windows method on Windows
+    def abspath(path):
+        """Return the absolute version of a path."""
+        try:
+            return _getfullpathname(normpath(path))
+        except (OSError, ValueError):
+            return _abspath_fallback(path)
+
+try:
+    from nt import _getfinalpathname, readlink as _nt_readlink
+except ImportError:
+    # realpath is a no-op on systems without _getfinalpathname support.
+    realpath = abspath
+else:
+    def _readlink_deep(path):
+        # These error codes indicate that we should stop reading links and
+        # return the path we currently have.
+        # 1: ERROR_INVALID_FUNCTION
+        # 2: ERROR_FILE_NOT_FOUND
+        # 3: ERROR_DIRECTORY_NOT_FOUND
+        # 5: ERROR_ACCESS_DENIED
+        # 21: ERROR_NOT_READY (implies drive with no media)
+        # 32: ERROR_SHARING_VIOLATION (probably an NTFS paging file)
+        # 50: ERROR_NOT_SUPPORTED (implies no support for reparse points)
+        # 67: ERROR_BAD_NET_NAME (implies remote server unavailable)
+        # 87: ERROR_INVALID_PARAMETER
+        # 4390: ERROR_NOT_A_REPARSE_POINT
+        # 4392: ERROR_INVALID_REPARSE_DATA
+        # 4393: ERROR_REPARSE_TAG_INVALID
+        allowed_winerror = 1, 2, 3, 5, 21, 32, 50, 67, 87, 4390, 4392, 4393
+
+        seen = set()
+        while normcase(path) not in seen:
+            seen.add(normcase(path))
+            try:
+                old_path = path
+                path = _nt_readlink(path)
+                # Links may be relative, so resolve them against their
+                # own location
+                if not isabs(path):
+                    # If it's something other than a symlink, we don't know
+                    # what it's actually going to be resolved against, so
+                    # just return the old path.
+                    if not islink(old_path):
+                        path = old_path
+                        break
+                    path = normpath(join(dirname(old_path), path))
+            except OSError as ex:
+                if ex.winerror in allowed_winerror:
+                    break
+                raise
+            except ValueError:
+                # Stop on reparse points that are not symlinks
+                break
+        return path
+
+    def _getfinalpathname_nonstrict(path):
+        # These error codes indicate that we should stop resolving the path
+        # and return the value we currently have.
+        # 1: ERROR_INVALID_FUNCTION
+        # 2: ERROR_FILE_NOT_FOUND
+        # 3: ERROR_DIRECTORY_NOT_FOUND
+        # 5: ERROR_ACCESS_DENIED
+        # 21: ERROR_NOT_READY (implies drive with no media)
+        # 32: ERROR_SHARING_VIOLATION (probably an NTFS paging file)
+        # 50: ERROR_NOT_SUPPORTED
+        # 53: ERROR_BAD_NETPATH
+        # 65: ERROR_NETWORK_ACCESS_DENIED
+        # 67: ERROR_BAD_NET_NAME (implies remote server unavailable)
+        # 87: ERROR_INVALID_PARAMETER
+        # 123: ERROR_INVALID_NAME
+        # 161: ERROR_BAD_PATHNAME
+        # 1920: ERROR_CANT_ACCESS_FILE
+        # 1921: ERROR_CANT_RESOLVE_FILENAME (implies unfollowable symlink)
+        allowed_winerror = 1, 2, 3, 5, 21, 32, 50, 53, 65, 67, 87, 123, 161, 1920, 1921
+
+        # Non-strict algorithm is to find as much of the target directory
+        # as we can and join the rest.
+        tail = path[:0]
+        while path:
+            try:
+                path = _getfinalpathname(path)
+                return join(path, tail) if tail else path
+            except OSError as ex:
+                if ex.winerror not in allowed_winerror:
+                    raise
+                try:
+                    # The OS could not resolve this path fully, so we attempt
+                    # to follow the link ourselves. If we succeed, join the tail
+                    # and return.
+                    new_path = _readlink_deep(path)
+                    if new_path != path:
+                        return join(new_path, tail) if tail else new_path
+                except OSError:
+                    # If we fail to readlink(), let's keep traversing
+                    pass
+                path, name = split(path)
+                # TODO (bpo-38186): Request the real file name from the directory
+                # entry using FindFirstFileW. For now, we will return the path
+                # as best we have it
+                if path and not name:
+                    return path + tail
+                tail = join(name, tail) if tail else name
+        return tail
+
+    def realpath(path, *, strict=False):
+        path = normpath(path)
+        if isinstance(path, bytes):
+            prefix = b'\\\\?\\'
+            unc_prefix = b'\\\\?\\UNC\\'
+            new_unc_prefix = b'\\\\'
+            cwd = os.getcwdb()
+            # bpo-38081: Special case for realpath(b'nul')
+            if normcase(path) == normcase(os.fsencode(devnull)):
+                return b'\\\\.\\NUL'
+        else:
+            prefix = '\\\\?\\'
+            unc_prefix = '\\\\?\\UNC\\'
+            new_unc_prefix = '\\\\'
+            cwd = os.getcwd()
+            # bpo-38081: Special case for realpath('nul')
+            if normcase(path) == normcase(devnull):
+                return '\\\\.\\NUL'
+        had_prefix = path.startswith(prefix)
+        if not had_prefix and not isabs(path):
+            path = join(cwd, path)
+        try:
+            path = _getfinalpathname(path)
+            initial_winerror = 0
+        except ValueError as ex:
+            # gh-106242: Raised for embedded null characters
+            # In strict mode, we convert into an OSError.
+            # Non-strict mode returns the path as-is, since we've already
+            # made it absolute.
+            if strict:
+                raise OSError(str(ex)) from None
+            path = normpath(path)
+        except OSError as ex:
+            if strict:
+                raise
+            initial_winerror = ex.winerror
+            path = _getfinalpathname_nonstrict(path)
+        # The path returned by _getfinalpathname will always start with \\?\ -
+        # strip off that prefix unless it was already provided on the original
+        # path.
+        if not had_prefix and path.startswith(prefix):
+            # For UNC paths, the prefix will actually be \\?\UNC\
+            # Handle that case as well.
+            if path.startswith(unc_prefix):
+                spath = new_unc_prefix + path[len(unc_prefix):]
+            else:
+                spath = path[len(prefix):]
+            # Ensure that the non-prefixed path resolves to the same path
+            try:
+                if _getfinalpathname(spath) == path:
+                    path = spath
+            except ValueError as ex:
+                # Unexpected, as an invalid path should not have gained a prefix
+                # at any point, but we ignore this error just in case.
+                pass
+            except OSError as ex:
+                # If the path does not exist and originally did not exist, then
+                # strip the prefix anyway.
+                if ex.winerror == initial_winerror:
+                    path = spath
+        return path
+
+
+# All supported version have Unicode filename support.
+supports_unicode_filenames = True
+
+def relpath(path, start=None):
+    """Return a relative version of a path"""
+    path = os.fspath(path)
+    if isinstance(path, bytes):
+        sep = b'\\'
+        curdir = b'.'
+        pardir = b'..'
+    else:
+        sep = '\\'
+        curdir = '.'
+        pardir = '..'
+
+    if start is None:
+        start = curdir
+
+    if not path:
+        raise ValueError("no path specified")
+
+    start = os.fspath(start)
+    try:
+        start_abs = abspath(normpath(start))
+        path_abs = abspath(normpath(path))
+        start_drive, _, start_rest = splitroot(start_abs)
+        path_drive, _, path_rest = splitroot(path_abs)
+        if normcase(start_drive) != normcase(path_drive):
+            raise ValueError("path is on mount %r, start on mount %r" % (
+                path_drive, start_drive))
+
+        start_list = [x for x in start_rest.split(sep) if x]
+        path_list = [x for x in path_rest.split(sep) if x]
+        # Work out how much of the filepath is shared by start and path.
+        i = 0
+        for e1, e2 in zip(start_list, path_list):
+            if normcase(e1) != normcase(e2):
+                break
+            i += 1
+
+        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
+        if not rel_list:
+            return curdir
+        return join(*rel_list)
+    except (TypeError, ValueError, 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 function is case-insensitive and 'separator-insensitive', i.e. if the
+# only difference between two paths is the use of '\' versus '/' as separator,
+# they are deemed to be equal.
+#
+# However, the returned path will have the standard '\' separator (even if the
+# given paths had the alternative '/' separator) and will have the case of the
+# first path given in the sequence. Additionally, 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'\\'
+        altsep = b'/'
+        curdir = b'.'
+    else:
+        sep = '\\'
+        altsep = '/'
+        curdir = '.'
+
+    try:
+        drivesplits = [splitroot(p.replace(altsep, sep).lower()) for p in paths]
+        split_paths = [p.split(sep) for d, r, p in drivesplits]
+
+        if len({r for d, r, p in drivesplits}) != 1:
+            raise ValueError("Can't mix absolute and relative paths")
+
+        # Check that all drive letters or UNC paths match. The check is made only
+        # now otherwise type errors for mixing strings and bytes would not be
+        # caught.
+        if len({d for d, r, p in drivesplits}) != 1:
+            raise ValueError("Paths don't have the same drive")
+
+        drive, root, path = splitroot(paths[0].replace(altsep, sep))
+        common = path.split(sep)
+        common = [c for c in common if c and c != curdir]
+
+        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)
+        for i, c in enumerate(s1):
+            if c != s2[i]:
+                common = common[:i]
+                break
+        else:
+            common = common[:len(s1)]
+
+        return drive + root + sep.join(common)
+    except (TypeError, AttributeError):
+        genericpath._check_arg_types('commonpath', *paths)
+        raise
+
+
+try:
+    # The isdir(), isfile(), islink() and exists() implementations in
+    # genericpath use os.stat(). This is overkill on Windows. Use simpler
+    # builtin functions if they are available.
+    from nt import _path_isdir as isdir
+    from nt import _path_isfile as isfile
+    from nt import _path_islink as islink
+    from nt import _path_exists as exists
+except ImportError:
+    # Use genericpath.* as imported above
+    pass
+
+
+try:
+    from nt import _path_isdevdrive
+except ImportError:
+    def isdevdrive(path):
+        """Determines whether the specified path is on a Windows Dev Drive."""
+        # Never a Dev Drive
+        return False
+else:
+    def isdevdrive(path):
+        """Determines whether the specified path is on a Windows Dev Drive."""
+        try:
+            return _path_isdevdrive(abspath(path))
+        except OSError:
+            return False