熊猫在奇数行取平均数

起始数据:

   time value value_1  value-2
0   0    0      4        3
1   2    1      6        6

   time value value_1  value-2
0   0    0      4        3
1   1    0      4        3     #duplicate of row 0
2   2    1      6        6
3   3    1      6        6     #duplicate of row 2

我想创建dfï1:

   time value value_1  value-2
0   0    0      4        3
1   1    0.5    5        4.5     #average of row 0 and 2
2   2    1      6        6
3   3    2      8        8       #average of row 2 and 4

为此,我附加了一个起始数据帧的副本,以创建如上所示的中间数据帧:

df = df_0.append(df_0)
df.sort_values(['time'], ascending=[True], inplace=True)
df = df.reset_index()
df['value_shift'] = df['value'].shift(-1)
df['value_shift_1'] = df['value_1'].shift(-1)
df['value_shift_2'] = df['value_2'].shift(-1)

然后我想对每一列应用一个函数:

def average_vals(numeric_val):
    #average every odd row
    if int(row.name) % 2 != 0:
        #take average of value and value_shift for each value
        #but this way I need to create 3 separate functions