20 monomials of degree 3 in 4 variables in lexicographic ordering

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Hey community, I've recently wanted to switch over to sage (very new) from Maple and I am having trouble understanding how to make monomials of degree 3 in 4 variables (hopefully in lexographic ordering think of the w coordinate as one). I am not very good at english, but this is for a Clebsch map up and down for a surface that I am studying.

These are the maps:
m1:=p-->p[1]^3;
m2:=p-->p[1]^2p;
m3:=p-->p[1]^2p[3];
m4:=p-->p[1]^2;
m5:=p-->p[1]p[2]^2;
m6:=p-->p[1]p[2]p[3];
m7:=p-->p[1]p[2];
m8:=p-->p[1]p[3]^2;
m9:=p-->p[1]p[3];
m10:=p-->p[1];
m11:=p-->p[2]^3;
m12:=p-->p[2]^2p[3];
m13:=p-->p[2]^2;
m14:=p-->p[2]p[3]^2;
m15:=p-->p[2]*p[3];
m16:=p-->p[2]; m17:=p-->p[3]^3;
m18:=p-->p[3]^2;
m19:=p-->p[3];
m20:=p-->1;
Then M:=[m1,m2,m3,m4,m5,m6,m7,m8,m9,m10,m11,m12,m13,m14,m15,m16,m17,m18,m19,m20]