return df iloc 5b1 3a 5d

1>>> df.iloc[1:3, 0:3]
2      a     b     c
31   100   200   300
42  1000  2000  3000
5

1Purely integer-location based indexing for selection by position.
2
3.iloc[] is primarily integer position based (from 0 to length-1 of the axis), but may also be used with a boolean array.