def find_missing_intervals(__df, interval):
    """find gaps in data dataframe
    Returns
    ----------
    list
        a list of all missing intervals
    """
    _df = __df.copy()
    import pandas as pd
    _df['data'] = True
    _df['Timestamp'] = pd.to_datetime(_df['Timestamp'])
    _df.set_index('Timestamp', inplace=True)
    _df = _df.reindex(pd.date_range(start=_df.index[0], end=_df.index[-1],
        freq='{0}s'.format(interval)))
    missing_timestamps = []
    for index, row in _df.iterrows():
        if row['data'] != True:
            missing_timestamps.append(index)
    return missing_timestamps, _df
