 'pandas.core.window.rolling.Window'>

        In order to use the `SciPy` Gaussian window we need to provide the parameters
        `M` and `std`. The parameter `M` corresponds to 2 in our example.
        We pass the second parameter `std` as a parameter of the following method
        (`sum` in this case):

        >>> ser.rolling(2, win_type='gaussian').sum(std=3)
        0         NaN
        1    0.986207
        2    5.917243
        3    6.903450
        4    9.862071
        dtype: float64
        