Fix minor NumPy compatibility warnings (#434)

Author: mhucka

recirq/hfvqe/objective_test.py

@@ -48,7 +48,7 @@ def get_opdm(wf, num_orbitals, transform=of.jordan_wigner):
     # not using display style objects
     for p, q in product(range(num_orbitals), repeat=2):
         operator = creation_ops[p] @ creation_ops[q].conj().transpose()
-        opdm_hw[p, q] = wf.conj().T @ operator @ wf
+        opdm_hw[p, q] = (wf.conj().T @ operator @ wf)[0, 0]
 
     return opdm_hw
 

recirq/toric_code/toric_code_plaquettes.py

@@ -109,10 +109,10 @@ def expectation_value(
             qubit_idxs = code.z_plaquette_to_qubit_idxs(row, col)
 
         total_qubits = len(code.qubits)
-        parities = data.applymap(
+        parities = data.map(
             lambda value: cls.compute_parity(value, qubit_idxs, total_qubits)
         )
-        return float(parities.mean())
+        return float(parities.mean().iloc[0])
 
     @staticmethod
     def compute_parity(value: int, qubit_idxs: Iterable[int], total_qubits: int) -> int: