Add missing randbytes method on random

Lib/random.py

@@ -59,7 +59,7 @@ __all__ = ["Random","seed","random","uniform","randint","choice","sample",
            "randrange","shuffle","normalvariate","lognormvariate",
            "expovariate","vonmisesvariate","gammavariate","triangular",
            "gauss","betavariate","paretovariate","weibullvariate",
-           "getstate","setstate", "getrandbits", "choices",
+           "getstate","setstate", "getrandbits", "randbytes", "choices",
            "SystemRandom"]
 
 NV_MAGICCONST = 4 * _exp(-0.5)/_sqrt(2.0)
@@ -775,6 +775,7 @@ weibullvariate = _inst.weibullvariate
 getstate = _inst.getstate
 setstate = _inst.setstate
 getrandbits = _inst.getrandbits
+randbytes = _inst.randbytes
 
 if hasattr(_os, "fork"):
     _os.register_at_fork(after_in_child=_inst.seed)

stdlib/src/random.rs

@@ -144,5 +144,13 @@ mod _random {
             };
             Ok(BigInt::from_biguint(sign, uint))
         }
+
+        #[pymethod]
+        fn randbytes(&self, n: usize) -> PyResult<Vec<u8>> {
+            let mut buf = vec![0u8; n];
+            let mut rng = self.rng.lock();
+            rng.fill_bytes(&mut buf);
+            Ok(buf)
+        }
     }
 }