I have a text file with 8 columns

# 0.y[m] 1.uy[m_e*c] 2.x[m] 3.ux[m_ec] 4.z[m] 5.uz[m_ec] 6.w 7.ID.

In this file, the first line is commented with # and there is no label for the data columns. I import this file in a data frame using

data = pd.DataFrame(pd.read_csv("41.dat", sep='t', comment='#', header=None));

and diplaying it I see:

Now, I need to sort ascending for the last column so I use index 7 and this code line

dataS = currentData.sort_values(7);

and sorting works because now I see

but sorting is not persistent because

data[7][0] = 24641553

and

dataS[7][0] = 24641553

I need to use the sorted data frame one row after the other, exactly in the sorted order, so my code will rely on a for loop which uses dataS[7][i] where i = 0, 1, 2, …

Can anyone help please? Thanks!