将dataframe索引转换为字符串和子字符串？

Question

想知道最简单的方法是将下面的数据帧索引拆分为子串,并将第二块设置为新数据帧中的列.

Input:
          Ask    Bid   Last Open_Int Vol
245.0P  11.36  11.15  10.41       37  30
225.0C  10.31  10.23   10.3       52   5
224.5C  10.78  10.67     12       72  72
223.5C  11.68  11.56  12.68       89  59
244.5P  10.83  10.64   8.65      118  22
244.0P  10.34  10.15   9.93      137  10

Output:
          Ask    Bid   Last Open_Int Vol Type
245.0P  11.36  11.15  10.41       37  30 P
225.0C  10.31  10.23   10.3       52   5 C
224.5C  10.78  10.67     12       72  72 C
223.5C  11.68  11.56  12.68       89  59 C
244.5P  10.83  10.64   8.65      118  22 P
244.0P  10.34  10.15   9.93      137  10 P

Answer 1

df.assign(Type=df.index.str[-1])

          Ask    Bid   Last  Open_Int  Vol Type
245.0P  11.36  11.15  10.41        37   30    P
225.0C  10.31  10.23  10.30        52    5    C
224.5C  10.78  10.67  12.00        72   72    C
223.5C  11.68  11.56  12.68        89   59    C
244.5P  10.83  10.64   8.65       118   22    P
244.0P  10.34  10.15   9.93       137   10    P

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