change of formatting and better compatibility

Author: Erertertet

setup.py

@@ -2,7 +2,7 @@
 
 from tensorcircuit import __version__, __author__
 
-with open("README.md", "r", encoding = "utf-8") as fh:
+with open("README.md", "r", encoding="utf-8") as fh:
     long_description = fh.read()
 
 

tensorcircuit/translation.py

@@ -18,12 +18,18 @@
     from qiskit.circuit.quantumcircuitdata import CircuitInstruction
     from qiskit.circuit.parametervector import ParameterVectorElement
     from qiskit.circuit import Parameter, ParameterExpression
-    import cirq
 except ImportError:
     logger.warning(
         "Please first ``pip install -U qiskit`` to enable related functionality in translation module"
     )
 
+try:
+    import cirq
+except ImportError:
+    logger.warning(
+        "Please first ``pip install -U cirq`` to enable related functionality in translation module"
+    )
+
 from . import gates
 from .circuit import Circuit
 from .densitymatrix import DMCircuit2
@@ -82,21 +88,6 @@ def _merge_extra_qir(
             nqir += inds[k]
     return nqir
 
-class CustomizedCirqGate(cirq.Gate):
-    def __init__(self, uMatrix, name, nqubit):
-        super(CustomizedCirqGate, self)
-        self.uMatrix = uMatrix
-        self.name    = name
-        self.nqubit  = nqubit
-
-    def _num_qubits_(self):
-        return self.nqubit
-
-    def _unitary_(self):
-        return self.uMatrix
-
-    def _circuit_diagram_info_(self, args):
-        return [self.name] * self.nqubit
 
 def qir2cirq(
     qir: List[Dict[str, Any]], n: int, extra_qir: Optional[List[Dict[str, Any]]] = None
@@ -124,51 +115,85 @@ def qir2cirq(
     :return: qiskit cirq object
     :rtype: Any
 
-    todo:
+    #TODO(@erertertet):
     add default theta to iswap gate
     add more cirq built-in gate instead of customized
     add unitary test with tolerance
     add support of cirq built-in ControlledGate for multiplecontroll
     support more element in qir, e.g. barrier, measure...
     disable outputting controlled bit when creating controlled gate
     """
+
+    class CustomizedCirqGate(cirq.Gate):
+        def __init__(self, uMatrix: Any, name: str, nqubit: int):
+            super(CustomizedCirqGate, self)
+            self.uMatrix = uMatrix
+            self.name = name
+            self.nqubit = nqubit
+
+        def _num_qubits_(self) -> int:
+            return self.nqubit
+
+        def _unitary_(self) -> Any:
+            return self.uMatrix
+
+        def _circuit_diagram_info_(self) -> List[str]:
+            return [self.name] * self.nqubit
+
     if extra_qir is not None and len(extra_qir) > 0:
         qir = _merge_extra_qir(qir, extra_qir)
     qbits = cirq.LineQubit.range(n)
-    cmd   = []
+    cmd = []
     for gate_info in qir:
         index = [qbits[i] for i in gate_info["index"]]
         gate_name = str(gate_info["gatef"])
         if "parameters" in gate_info:
             parameters = gate_info["parameters"]
-        if gate_name in ["h","i","x","y","z","s","t","fredkin","toffoli","cnot","swap"]:
+        if gate_name in [
+            "h",
+            "i",
+            "x",
+            "y",
+            "z",
+            "s",
+            "t",
+            "fredkin",
+            "toffoli",
+            "cnot",
+            "swap",
+        ]:
             cmd.append(getattr(cirq, gate_name.upper())(*index))
         elif gate_name in ["rx", "ry", "rz"]:
-            cmd.append(getattr(cirq, gate_name)(_get_float(parameters, "theta")).on(*index))
+            cmd.append(
+                getattr(cirq, gate_name)(_get_float(parameters, "theta")).on(*index)
+            )
         elif gate_name == "iswap":
-            if "theta" not in parameters:
-                cmd.append(cirq.ISWAP(*index))
-                # when ISWAP theta is not specified, _get_float will return default value of 0.0 instead of 1.0
-            else:
-                cmd.append(cirq.ISwapPowGate(exponent = _get_float(parameters, "theta")).on(*index))
+            cmd.append(
+                cirq.ISwapPowGate(
+                    exponent=_get_float(parameters, "theta", default=1)
+                ).on(*index)
+            )
         elif gate_name in ["mpo", "multicontrol"]:
             gatem = np.reshape(
-                    backend.numpy(gate_info["gatef"](**parameters).eval_matrix()),
-                    [2 ** len(index), 2 ** len(index)],
-                )
+                backend.numpy(gate_info["gatef"](**parameters).eval_matrix()),
+                [2 ** len(index), 2 ** len(index)],
+            )
             ci_name = gate_info["name"]
             cgate = CustomizedCirqGate(gatem, ci_name, len(index))
             cmd.append(cgate.on(*index))
         else:
             # Add Customized Gate if there is no match
-            gatem = np.reshape(gate_info["gate"].tensor,[2 ** len(index), 2 ** len(index)],
+            gatem = np.reshape(
+                gate_info["gate"].tensor,
+                [2 ** len(index), 2 ** len(index)],
             )
             # Note: unitary test is not working for some of the generated matrix, probably add tolerance unitary test later
             cgate = CustomizedCirqGate(gatem, gate_name, len(index))
             cmd.append(cgate.on(*index))
     cirq_circuit = cirq.Circuit(*cmd)
     return cirq_circuit
 
+
 def qir2qiskit(
     qir: List[Dict[str, Any]], n: int, extra_qir: Optional[List[Dict[str, Any]]] = None
 ) -> Any:

tests/test_circuit.py

@@ -857,11 +857,11 @@ def test_circuit_quoperator(backend):
     qo = c.quoperator()
     np.testing.assert_allclose(qo.eval_matrix(), c.matrix(), atol=1e-5)
 
+
 @pytest.mark.parametrize("backend", [lf("npb"), lf("tfb"), lf("jaxb")])
 def test_qir2cirq(backend):
     try:
         import cirq
-        from tensorcircuit.translation import perm_matrix
     except ImportError:
         pytest.skip("cirq is not installed")
     n = 6
@@ -953,7 +953,7 @@ def test_qir2cirq(backend):
     cirq_unitary = cirq.unitary()
     cirq_unitary = np.reshape(cirq_unitary, [2**n, 2**n])
 
-    np.testing.assert_allclose(tc_unitary, cirq_unitary, atol = 1e-5)
+    np.testing.assert_allclose(tc_unitary, cirq_unitary, atol=1e-5)
 
 
 @pytest.mark.parametrize("backend", [lf("npb"), lf("tfb"), lf("jaxb")])