Pandas 增加列值有条件到另一列

Question

What's wrong with this approach

df['max'] = np.where((df[df['category'] == 'basket']['width'] == 0), df['max']+10, df['max'])

so essentially I would like to update df['max'] based on the condition where df['category'] equals basket and the width of those equals 0 . If this is the case I would like to increase all df['max'] values by 10 if not I would just like to keep it the same.

This returns the following error

ValueError: operands could not be broadcast together with shapes (17,) (55,) (55,) 

Input

    max    category   width
0   181     basket     0  
1   745     basket     10

desired output

    max    category   width
0   191     basket     0  
1   745     basket     10

Answer 1

With given input this worked on my side.

df["max"] = np.where((df["category"]=="basket")&(df["width"]==0), df["max"]+10, df["max"])
print(df)

   max category  width
0  191   basket      0
1  745   basket     10