def clean_worksheet(wks, gfile_id, wks_name, credentials):
    """DOCS..."""

    values = wks.get_all_values()
    if values:
        df_ = pd.DataFrame(index=range(len(values)),
                           columns=range(len(values[0])))
        df_ = df_.fillna('')
        wks = upload(df_, gfile_id, wks_name=wks_name,
                     col_names=False, row_names=False, clean=False,
                     credentials=credentials)
    return wks