Pandas，Multiple Case Statement，ValueError:应该同时给出x和y或两者都不给出

Question

尝试在我的代码中合并以下case语句。你知道吗

d1['newcol'] = np.where((d1['business_name'] == 'HELP')&(d1['level'] == 'Component'), d1['component'], np.where((d1['business_name'] == 'HELP')&(d1['level'] == 'Package'),d1['package'], np.where(d1['business_name'] == 'PHELPS',d1['reporting']))) 

或者案例伪代码看起来像：

   newcol=case WHEN ((business_name = 'HELP' AND level = 'Component')) THEN component WHEN ((business_name = 'HELP' AND level = 'Package')) THEN package WHEN (business_name = 'PHELS') THEN reporting END

我得到的错误是：

ValueError: either both or neither of x and y should be given

任何帮助都将不胜感激。你知道吗

Answer 1

您可能希望在数据帧的所有行上应用lambda函数。你知道吗

df['newcol'] = df.apply(lambda row: 
                        row['component'] if row['business_name'] == 'help' and row['level'] == 'Component' # 1st condition
                           else (row['package'] if row['business_name'] == 'HELP' and row['level'] == 'Package' # 2nd condition
                                 else (row['reporting'] if row['business_name'] == 'PHELPS' # 3rd condition
                                       else np.nan) # NAN if no conditions matched
                           )
                       , axis=1)