Consider the pandas DataFrame df: id var_day 0 1 x_0 1 2 y_0 2 3 x_1 Complete the code to return the output df['var'] = df. df Expected Output id var_day var 0 1 x_0 x 1 2 y_0 y 2 3 x_1 x code example

Example 1: iloc pandas

Purely integer-location based indexing for selection by position.

.iloc[] is primarily integer position based (from 0 to length-1 of the axis), but may also be used with a boolean array.

Example 2: iloc python

>>> df.iloc[[0, 1]]
     a    b    c    d
0    1    2    3    4
1  100  200  300  400