df.iloc[0]['x'] = 0 df.iloc[0]['y'] = 0 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: return df.iloc[1:]

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