Update index after sorting data-frame

Question

Take the following data-frame:

x = np.tile(np.arange(3),3)
y = np.repeat(np.arange(3),3)
df = pd.DataFrame({\"x\": x, \"y\": y})

Answer 1

You can set new indices by using set_index:

df2.set_index(np.arange(len(df2.index)))

Output:

   x  y
0  0  0
1  0  1
2  0  2
3  1  0
4  1  1
5  1  2
6  2  0
7  2  1
8  2  2