def sma(ohlcv, period=10, ohlcv_series="close"):
    """
    Calculate simple moving average of the input data

    :param _ohlcv: ohlcv dataframe
    :type _ohlcv: pd.DataFrame
    :param period: how many periods to look back
    :type period: int
    :param ohlcv_series: which of the o/h/l/v to use
    :type ohlcv_series: str
    :return: pd.series
    """
    _ohlcv = ohlcv[[ohlcv_series]].copy(deep=True)
    indicator_values = _ohlcv[ohlcv_series].rolling(window=period, min_periods=period).mean()

    return indicator_values