Python genericpath 模块，_check_arg_types() 实例源码

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    a = os.fspath(a)
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in map(os.fspath, p):
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    path = os.fspath(path)
    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir
    else:
        start = os.fspath(start)

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    a = os.fspath(a)
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in map(os.fspath, p):
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    path = os.fspath(path)
    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir
    else:
        start = os.fspath(start)

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    a = os.fspath(a)
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in map(os.fspath, p):
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    path = os.fspath(path)
    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir
    else:
        start = os.fspath(start)

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in p:
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in p:
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in p:
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in p:
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in p:
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in p:
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in p:
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in p:
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def join(a, *p):
    """Join two or more pathname components, inserting '/' as needed.
    If any component is an absolute path, all previous path components
    will be discarded.  An empty last part will result in a path that
    ends with a separator."""
    sep = _get_sep(a)
    path = a
    try:
        if not p:
            path[:0] + sep  #23780: Ensure compatible data type even if p is null.
        for b in p:
            if b.startswith(sep):
                path = b
            elif not path or path.endswith(sep):
                path += b
            else:
                path += sep + b
    except (TypeError, AttributeError, BytesWarning):
        genericpath._check_arg_types('join', a, *p)
        raise
    return path


# Split a path in head (everything up to the last '/') and tail (the
# rest).  If the path ends in '/', tail will be empty.  If there is no
# '/' in the path, head  will be empty.
# Trailing '/'es are stripped from head unless it is the root.

def relpath(path, start=None):
    """Return a relative version of a path"""

    if not path:
        raise ValueError("no path specified")

    if isinstance(path, bytes):
        curdir = b'.'
        sep = b'/'
        pardir = b'..'
    else:
        curdir = '.'
        sep = '/'
        pardir = '..'

    if start is None:
        start = curdir

    try:
        start_list = [x for x in abspath(start).split(sep) if x]
        path_list = [x for x in abspath(path).split(sep) if x]
        # Work out how much of the filepath is shared by start and path.
        i = len(commonprefix([start_list, path_list]))

        rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
        if not rel_list:
            return curdir
        return join(*rel_list)
    except (TypeError, AttributeError, BytesWarning, DeprecationWarning):
        genericpath._check_arg_types('relpath', path, start)
        raise


# Return the longest common sub-path of the sequence of paths given as input.
# The paths are not normalized before comparing them (this is the
# responsibility of the caller). Any trailing separator is stripped from the
# returned path.

def 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_path = splitdrive(path)
        for p in map(os.fspath, paths):
            p_drive, p_path = splitdrive(p)
            if p_path and p_path[0] in seps:
                # Second path is absolute
                if p_drive or not result_drive:
                    result_drive = p_drive
                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_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 result_path[0] not in seps and
            result_drive and result_drive[-1:] != colon):
            return result_drive + sep + result_path
        return result_drive + 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 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 = splitdrive(start_abs)
        path_drive, path_rest = splitdrive(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 = [splitdrive(p.replace(altsep, sep).lower()) for p in paths]
        split_paths = [p.split(sep) for d, p in drivesplits]

        try:
            isabs, = set(p[:1] == sep for d, p in drivesplits)
        except ValueError:
            raise ValueError("Can't mix absolute and relative paths") from None

        # 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(set(d for d, p in drivesplits)) != 1:
            raise ValueError("Paths don't have the same drive")

        drive, path = splitdrive(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)]

        prefix = drive + sep if isabs else drive
        return prefix + sep.join(common)
    except (TypeError, AttributeError):
        genericpath._check_arg_types('commonpath', *paths)
        raise


# determine if two files are in fact the same file

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_path = splitdrive(path)
        for p in map(os.fspath, paths):
            p_drive, p_path = splitdrive(p)
            if p_path and p_path[0] in seps:
                # Second path is absolute
                if p_drive or not result_drive:
                    result_drive = p_drive
                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_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 result_path[0] not in seps and
            result_drive and result_drive[-1:] != colon):
            return result_drive + sep + result_path
        return result_drive + 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 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 = splitdrive(start_abs)
        path_drive, path_rest = splitdrive(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 = [splitdrive(p.replace(altsep, sep).lower()) for p in paths]
        split_paths = [p.split(sep) for d, p in drivesplits]

        try:
            isabs, = set(p[:1] == sep for d, p in drivesplits)
        except ValueError:
            raise ValueError("Can't mix absolute and relative paths") from None

        # 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(set(d for d, p in drivesplits)) != 1:
            raise ValueError("Paths don't have the same drive")

        drive, path = splitdrive(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)]

        prefix = drive + sep if isabs else drive
        return prefix + sep.join(common)
    except (TypeError, AttributeError):
        genericpath._check_arg_types('commonpath', *paths)
        raise


# determine if two files are in fact the same file

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_path = splitdrive(path)
        for p in map(os.fspath, paths):
            p_drive, p_path = splitdrive(p)
            if p_path and p_path[0] in seps:
                # Second path is absolute
                if p_drive or not result_drive:
                    result_drive = p_drive
                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_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 result_path[0] not in seps and
            result_drive and result_drive[-1:] != colon):
            return result_drive + sep + result_path
        return result_drive + 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 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 = splitdrive(start_abs)
        path_drive, path_rest = splitdrive(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 = [splitdrive(p.replace(altsep, sep).lower()) for p in paths]
        split_paths = [p.split(sep) for d, p in drivesplits]

        try:
            isabs, = set(p[:1] == sep for d, p in drivesplits)
        except ValueError:
            raise ValueError("Can't mix absolute and relative paths") from None

        # 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(set(d for d, p in drivesplits)) != 1:
            raise ValueError("Paths don't have the same drive")

        drive, path = splitdrive(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)]

        prefix = drive + sep if isabs else drive
        return prefix + sep.join(common)
    except (TypeError, AttributeError):
        genericpath._check_arg_types('commonpath', *paths)
        raise


# determine if two files are in fact the same file

def join(path, *paths):
    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_path = splitdrive(path)
        for p in paths:
            p_drive, p_path = splitdrive(p)
            if p_path and p_path[0] in seps:
                # Second path is absolute
                if p_drive or not result_drive:
                    result_drive = p_drive
                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_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 result_path[0] not in seps and
            result_drive and result_drive[-1:] != colon):
            return result_drive + sep + result_path
        return result_drive + 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 relpath(path, start=None):
    """Return a relative version of a 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")

    try:
        start_abs = abspath(normpath(start))
        path_abs = abspath(normpath(path))
        start_drive, start_rest = splitdrive(start_abs)
        path_drive, path_rest = splitdrive(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')

    if isinstance(paths[0], bytes):
        sep = b'\\'
        altsep = b'/'
        curdir = b'.'
    else:
        sep = '\\'
        altsep = '/'
        curdir = '.'

    try:
        drivesplits = [splitdrive(p.replace(altsep, sep).lower()) for p in paths]
        split_paths = [p.split(sep) for d, p in drivesplits]

        try:
            isabs, = set(p[:1] == sep for d, p in drivesplits)
        except ValueError:
            raise ValueError("Can't mix absolute and relative paths") from None

        # 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(set(d for d, p in drivesplits)) != 1:
            raise ValueError("Paths don't have the same drive")

        drive, path = splitdrive(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)]

        prefix = drive + sep if isabs else drive
        return prefix + sep.join(common)
    except (TypeError, AttributeError):
        genericpath._check_arg_types('commonpath', *paths)
        raise


# determine if two files are in fact the same file

def join(path, *paths):
    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_path = splitdrive(path)
        for p in paths:
            p_drive, p_path = splitdrive(p)
            if p_path and p_path[0] in seps:
                # Second path is absolute
                if p_drive or not result_drive:
                    result_drive = p_drive
                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_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 result_path[0] not in seps and
            result_drive and result_drive[-1:] != colon):
            return result_drive + sep + result_path
        return result_drive + 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 relpath(path, start=None):
    """Return a relative version of a 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")

    try:
        start_abs = abspath(normpath(start))
        path_abs = abspath(normpath(path))
        start_drive, start_rest = splitdrive(start_abs)
        path_drive, path_rest = splitdrive(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')

    if isinstance(paths[0], bytes):
        sep = b'\\'
        altsep = b'/'
        curdir = b'.'
    else:
        sep = '\\'
        altsep = '/'
        curdir = '.'

    try:
        drivesplits = [splitdrive(p.replace(altsep, sep).lower()) for p in paths]
        split_paths = [p.split(sep) for d, p in drivesplits]

        try:
            isabs, = set(p[:1] == sep for d, p in drivesplits)
        except ValueError:
            raise ValueError("Can't mix absolute and relative paths") from None

        # 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(set(d for d, p in drivesplits)) != 1:
            raise ValueError("Paths don't have the same drive")

        drive, path = splitdrive(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)]

        prefix = drive + sep if isabs else drive
        return prefix + sep.join(common)
    except (TypeError, AttributeError):
        genericpath._check_arg_types('commonpath', *paths)
        raise


# determine if two files are in fact the same file

def join(path, *paths):
    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_path = splitdrive(path)
        for p in paths:
            p_drive, p_path = splitdrive(p)
            if p_path and p_path[0] in seps:
                # Second path is absolute
                if p_drive or not result_drive:
                    result_drive = p_drive
                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_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 result_path[0] not in seps and
            result_drive and result_drive[-1:] != colon):
            return result_drive + sep + result_path
        return result_drive + 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 relpath(path, start=None):
    """Return a relative version of a 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")

    try:
        start_abs = abspath(normpath(start))
        path_abs = abspath(normpath(path))
        start_drive, start_rest = splitdrive(start_abs)
        path_drive, path_rest = splitdrive(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')

    if isinstance(paths[0], bytes):
        sep = b'\\'
        altsep = b'/'
        curdir = b'.'
    else:
        sep = '\\'
        altsep = '/'
        curdir = '.'

    try:
        drivesplits = [splitdrive(p.replace(altsep, sep).lower()) for p in paths]
        split_paths = [p.split(sep) for d, p in drivesplits]

        try:
            isabs, = set(p[:1] == sep for d, p in drivesplits)
        except ValueError:
            raise ValueError("Can't mix absolute and relative paths") from None

        # 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(set(d for d, p in drivesplits)) != 1:
            raise ValueError("Paths don't have the same drive")

        drive, path = splitdrive(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)]

        prefix = drive + sep if isabs else drive
        return prefix + sep.join(common)
    except (TypeError, AttributeError):
        genericpath._check_arg_types('commonpath', *paths)
        raise


# determine if two files are in fact the same file