How to reverse the values of specific rows in dataframe pandas

Question

ii=0 ...jj=0 ...for i, row in new_df.iterrows():
z=len(row)-1
k=row
ii=ii+1
jj=0
##print(k.iloc[0])
for j, column in row.iteritems():
    z=z-1
    jj=jj+1
    if z>2