def rename_file(source, dest):
    """ Rename (mv) file(s) from source to dest

    >>> from tempfile import mkdtemp
    >>> tmpdir = mkdtemp(suffix='doctest_rename_file', prefix='tmp')
    >>> fout = ensure_open(os.path.join(tmpdir, 'fake_data.bin.gz'), 'w')
    >>> fout.write(b'fake nlpia.loaders.rename_file')
    30
    >>> fout.close()
    >>> dest = rename_file(os.path.join(tmpdir, 'fake_data.bin.gz'), os.path.join(tmpdir, 'Fake_Data.bin.gz'))
    >>> os.path.isfile(os.path.join(tmpdir, 'Fake_Data.bin.gz'))
    True
    """
    logger.debug('nlpia.loaders.rename_file(source={}, dest={})'.format(source, dest))
    if not isinstance(source, str):
        dest = [dest] if isinstance(dest, str) else dest
        return [rename_file(s, d) for (s, d) in zip_longest(source, dest, fillvalue=[source, dest][int(len(source) > len(dest))])]
    logger.debug('nlpia.loaders.os.rename(source={}, dest={})'.format(source, dest))
    if source == dest:
        return dest
    os.rename(source, dest)
    return dest
Rename (mv) file(s) from source to dest

    >>> from tempfile import mkdtemp
    >>> tmpdir = mkdtemp(suffix='doctest_rename_file', prefix='tmp')
    >>> fout = ensure_open(os.path.join(tmpdir, 'fake_data.bin.gz'), 'w')
    >>> fout.write(b'fake nlpia.loaders.rename_file')
    30
    >>> fout.close()
    >>> dest = rename_file(os.path.join(tmpdir, 'fake_data.bin.gz'), os.path.join(tmpdir, 'Fake_Data.bin.gz'))
    >>> os.path.isfile(os.path.join(tmpdir, 'Fake_Data.bin.gz'))
    True