如何为pandas中的所有列值添加前缀

Question

我有以下熊猫数据框

 Date        stockA     stockB     stockC     stockD   stockE
 2020-01-01  1          1          2          1        3
 2020-01-01  1          2          2          1        2
 2020-01-01  1          1          3          2        1
 2020-01-01  3          1          2          1        2

我想为每列添加前缀，例如stockA:01、stockB:02等等

我想要的数据帧是

 Date        stockA     stockB     stockC     stockD   stockE
 2020-01-01  011         021        032        041     053
 2020-01-01  011         022        032        041     052
 2020-01-01  011         021        033        042     051
 2020-01-01  013         021        032        041     052

我也有25列。我怎样才能在熊猫身上做呢

Answer 1

使用：

m = df.columns.str.contains('stock')
cols_change = df.columns[m]
num = ('0'+pd.Index(range(1,len(cols_change)+1)).astype(str)).str[-2:]

df.columns = df.columns[~m].tolist()+[f'{name}:{n}' for n,name in zip(num,cols_change)]
print(df)
         Date  stockA:01  stockB:02  stockC:03  stockD:04  stockE:05
0  2020-01-01          1          1          2          1          3
1  2020-01-01          1          2          2          1          2
2  2020-01-01          1          1          3          2          1
3  2020-01-01          3          1          2          1          2

或与^{}

cols_change = df.columns.difference(['Date'])
num = ('0'+pd.Index(range(1,len(cols_change)+1)).astype(str)).str[-2:]

df.columns = ['Date']+[f'{name}:{n}' for n,name in zip(num,cols_change)]