Pandas/numpy Weighted Average Zerodivisionerror

Creating a lambda function to calculate weighted average and sending that to a dictionary. wm = lambda x: np.average(x, weights=df.loc[x.index, 'WEIGHTS']) # Define a dictionary

Solution 1:

Shouldn't this be enough?

def wm(x):
    try: 
        return np.average(x, weights=df.loc[x.index, 'WEIGHTS'])
    except ZeroDivisionError:
        return 0

f = {'DRESS_AMT': 'max', 
     'FACE_AMT': 'sum',
     'Other_AMT': {'weighted_mean' : wm} }

df2=df.groupby(['ID','COL1'], as_index=False).agg(f)