def serialize_paulisum(paulisum):
"""Constructs a pauli_sum proto from `cirq.PauliSum` or `cirq.PauliString`.
Args:
paulisum: A `cirq.PauliSum` object.
Returns:
A pauli_sum proto object.
"""
if isinstance(paulisum, cirq.PauliString):
paulisum = cirq.PauliSum.from_pauli_strings(paulisum)
if not isinstance(paulisum, cirq.PauliSum):
raise TypeError("serialize requires a cirq.PauliSum object."
" Given: " + str(type(paulisum)))
if any(not isinstance(qubit, cirq.GridQubit) for qubit in paulisum.qubits):
raise ValueError("Attempted to serialize a paulisum that doesn't use "
"only cirq.GridQubits.")
paulisum_proto = pauli_sum_pb2.PauliSum()
for term in paulisum:
pauliterm_proto = pauli_sum_pb2.PauliTerm()
pauliterm_proto.coefficient_real = term.coefficient.real
pauliterm_proto.coefficient_imag = term.coefficient.imag
for t in sorted(term.items()): # sort to keep qubits ordered.
pauliterm_proto.paulis.add(
qubit_id=v2.qubit_to_proto_id(t[0]),
pauli_type=str(t[1]),
)
paulisum_proto.terms.extend([pauliterm_proto])
return paulisum_proto
def _build_pauli_proto(coefs, ops, qubit_ids):
"""Construct pauli_sum proto explicitly."""
terms = []
for i in range(len(coefs)):
term = pauli_sum_pb2.PauliTerm()
term.coefficient_real = coefs[i].real
term.coefficient_imag = coefs[i].imag
for j in range(len(qubit_ids[i])):
term.paulis.add(qubit_id=qubit_ids[i][j], pauli_type=ops[i][j])
terms.append(term)
a = pauli_sum_pb2.PauliSum()
a.terms.extend(terms)
return a
