def _abspath_split(path):

    abs = abspath(normpath(path))

    prefix, rest = splitunc(abs)

    is_unc = bool(prefix)

    if not is_unc:

        prefix, rest = splitdrive(abs)

    return is_unc, prefix, [x for x in rest.split(sep) if x]

def relpath(path, start=curdir):

    """Return a relative version of a path"""

    if not path:

        raise ValueError("no path specified")

    start_is_unc, start_prefix, start_list = _abspath_split(start)

    path_is_unc, path_prefix, path_list = _abspath_split(path)

    if path_is_unc ^ start_is_unc:

        raise ValueError("Cannot mix UNC and non-UNC paths (%s and %s)"

                                                            % (path, start))

    if path_prefix.lower() != start_prefix.lower():

        if path_is_unc:

            raise ValueError("path is on UNC root %s, start on UNC root %s"

                                                % (path_prefix, start_prefix))

        else:

            raise ValueError("path is on drive %s, start on drive %s"

                                                % (path_prefix, start_prefix))

    # 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 e1.lower() != e2.lower():

            break

        i += 1

    rel_list = [pardir] * (len(start_list)-i) + path_list[i:]

    if not rel_list:

        return curdir

    return join(*rel_list)

def ownrelpath(a,b):

    relpath = '';

    la = a.split('/');

    lb = b.split('/');

    L = len(lb)-1;

    tt = '';

    for i in range(len(la)-1):

        if la[i] == lb[i] and tt =='':

            continue;

        else:

            tt = tt+la[i]+"\\";

            relpath =  "..\\"*(L-1);

    print(relpath+tt);