# How to get the graded part of a graded ring?

I have a graded quotient of a graded polynomial ring, say something like

```
P = PolynomialRing(QQ, , 'x,y,z', order=TermOrder('wdegrevlex',(1,2,3)))
I = P.ideal(x*y^2 + x^5, z*y + x^3*y)
Q = P.quotient(I)
```

I would like to get the vector space over QQ consisting on vectors of degree, say 9, in Q.