izmir = pd.read_excel(filepath)
izmir_lim = izmir[['Gender','Age','MC_OLD_M>=60','MC_OLD_F>=60',
'MC_OLD_M>18','MC_OLD_F>18','MC_OLD_18>M>5',
'MC_OLD_18>F>5','MC_OLD_M_Child<5','MC_OLD_F_Child<5',
'MC_OLD_M>0<=1','MC_OLD_F>0<=1','Date to Delivery',
'Date to insert','Date of Entery']]
izmir_lim
是一个视图/副本izmir
。您随后尝试分配给它。这就是引发错误的原因。使用这个代替:
izmir_lim = izmir[['Gender','Age','MC_OLD_M>=60','MC_OLD_F>=60',
'MC_OLD_M>18','MC_OLD_F>18','MC_OLD_18>M>5',
'MC_OLD_18>F>5','MC_OLD_M_Child<5','MC_OLD_F_Child<5',
'MC_OLD_M>0<=1','MC_OLD_F>0<=1','Date to Delivery',
'Date to insert','Date of Entery']].copy()
每当您通过以下方式从另一个数据帧“创建”新数据帧时:
new_df = old_df[list_of_columns_names]
new_df
将具有真实的价值is_copy
属性。当您尝试分配给它时,pandas 会抛出SettingWithCopyWarning
.
new_df.iloc[0, 0] = 1 # Should throw an error
您可以通过多种方式克服这个问题。
选项1
new_df = old_df[list_of_columns_names].copy()
选项#2(正如@ayhan 在评论中建议的那样)
new_df = old_df[list_of_columns_names]
new_df.is_copy = None
选项#3
new_df = old_df.loc[:, list_of_columns_names]