How to order a python dataframe by adding the row values? I have the following dataframe:

    M1  M2  M4   M5
N1  45  46  54   57
N2  32  36  29   56
N3  56  44  40   55
N4  57  43  42   54


How is it possible to order it according to the sum of its lines, from the largest sum to the lowest? That is, N1 in the first line, because the sum of the line values ​​is the largest, then N4, N3 and finally N2 (because the sum of the values ​​is the smallest). Thus:

    M1  M2  M4   M5
N1  45  46  54   57
N4  57  43  42   54
N3  56  44  40   55
N2  32  36  29   56
#create data
DF=pd.DataFrame(columns=["M1", "M2", "M3", "M4"])
DF.loc[0]=[45, 46, 54 , 57]
DF.loc[1]=[32 ,36 ,29 ,56]
DF.loc[2]=[56,44 ,40 ,55]
DF.loc[3]=[57 ,43 ,42 ,54]
DF=DF.astype(int)

#main function

DF["sum_"]=DF.apply(lambda x: sum(x), axis=1)
DF.sort_values("sum_", ascending=False)