def pdf ( x , mu , std ) : return ( 1.0 / ( std * sqrt ( 2 * pi ) ) ) * np . exp ( - ( x - mu ) ** 2 / ( 2 * std ** 2 ) )
python var and distribution of probability
Probability density function ( normal distribution )
def pdf(x, mu, std):
    """Probability density function (normal distribution)"""
    return (1.0 / (std * sqrt(2 * pi))) * np.exp(-(x - mu) ** 2 / (2 * std ** 2))