I want to make a function that take the average of a column but with two conditions:

1. Include only values greater than 0
2. Replace outliers* with the median

*In this case, an outlier is defined as a value that is beyond one standard deviation of the mean

This is what I have:

def AdjustedAverage(df, head):
    NoZeros = df[df[head] > 0]
    Median = NoZeros[head].median()
    Mean = NoZeros[head].mean()
    std = NoZeros[head].std()
    Max = Mean + std
    Min = Mean - std
    sum = 0
    for i in range(len(NoZeros)):
        if NoZeros[head][i] < Min or NoZeros[head][i] > Max:
            sum += Median
        else:
            sum += NoZeros[head][i]
    avg = sum / len(NoZeros)
    return avg

The KeyError appears in the “if” statement line. When I write the function’s code on the main code it works, but when I put in a function it raises a KeyError:0. I really want to create a function for this because I’ll use it many times in my code.

I don’t get why I get a KeyError. In the preceding lines, the “head” value is found, but suddenly in the If statement the program doesn’t find it anymore…

I tried to change the if statement with at or loc but I still get KeyError.