Allow Circuit.draw to display string directly

doc/source/code-examples/advancedexamples.rst

@@ -1151,7 +1151,7 @@ Additionally, one can also pass single-qubit readout error probabilities (`reado
     )
 
     print("raw circuit:")
-    print(circuit.draw())
+    circuit.draw()
 
     parameters = {
         "t1": {"0": 250*1e-06, "1": 240*1e-06},
@@ -1168,7 +1168,7 @@ Additionally, one can also pass single-qubit readout error probabilities (`reado
     noisy_circuit = noise_model.apply(circuit)
 
     print("noisy circuit:")
-    print(noisy_circuit.draw())
+    noisy_circuit.draw()
 
 .. testoutput::
    :hide:
@@ -1242,7 +1242,7 @@ Let's see how to use them. For starters, let's define a dummy circuit with some
    circ.add(gates.M(*range(nqubits)))
 
    # visualize the circuit
-   print(circ.draw())
+   circ.draw()
 
    #  q0: ─RZ─RX─RZ─RX─RZ─o────o────────M─
    #  q1: ─RZ─RX─RZ─RX─RZ─X─RZ─X─o────o─M─

doc/source/code-examples/examples.rst

@@ -310,7 +310,7 @@ For example
     from qibo.models import QFT
 
     c = QFT(5)
-    print(c.draw())
+    print(c.draw(output_string=True))
     # Prints
     '''
     q0: ─H─U1─U1─U1─U1───────────────────────────x───

examples/adiabatic_qml/adiabatic-qml.ipynb

@@ -568,7 +568,7 @@
     "circ1 = rotcirc.rotations_circuit(t=0.1)\n",
     "circ2 = rotcirc.rotations_circuit(t=0.8)\n",
     "\n",
-    "print(f\"Circuit diagram: {circ1.draw()}\")\n",
+    "print(f\"Circuit diagram: {circ1.draw(output_string=True)}\")\n",
     "print(f\"\\nCirc1 params: {circ1.get_parameters()}\")\n",
     "print(f\"\\nCirc2 params: {circ2.get_parameters()}\")"
    ]

examples/anomaly_detection/test.py

@@ -99,7 +99,7 @@ def compute_loss_test(encoder, vector):
     encoder_test = make_encoder(n_qubits, n_layers, trained_params, q_compression)
     encoder_test.compile()
     print("Circuit model summary")
-    print(encoder_test.draw())
+    encoder_test.draw()
 
     print("Computing losses...")
     # Compute loss for standard data

examples/anomaly_detection/train.py

@@ -123,7 +123,7 @@ def train_step(batch_size, encoder, params, dataset):
     # Create and print encoder circuit
     encoder = make_encoder(n_qubits, n_layers, params, q_compression)
     print("Circuit model summary")
-    print(encoder.draw())
+    encoder.draw()
 
     # Define optimizer parameters
     steps_for_epoch = math.ceil(train_size / batch_size)

examples/qcnn_classifier/qcnn_demo.ipynb

@@ -240,7 +240,7 @@
    "source": [
     "test = QuantumCNN(nqubits=4, nlayers=1, nclasses=2)\n",
     "testcircuit = test._circuit\n",
-    "print(testcircuit.draw())"
+    "testcircuit.draw()"
    ]
   },
   {

src/qibo/gates/abstract.py

@@ -268,7 +268,7 @@ def on_qubits(self, qubit_map) -> "Gate":
                 c.add(gates.CNOT(2, 3).on_qubits({2: 3, 3: 0})) # equivalent to gates.CNOT(3, 0)
                 c.add(gates.CNOT(2, 3).on_qubits({2: 1, 3: 3})) # equivalent to gates.CNOT(1, 3)
                 c.add(gates.CNOT(2, 3).on_qubits({2: 2, 3: 1})) # equivalent to gates.CNOT(2, 1)
-                print(c.draw())
+                c.draw()
             .. testoutput::
 
                 q0: ───X─────

src/qibo/gates/measurements.py

@@ -247,7 +247,7 @@ def on_qubits(self, qubit_map) -> "Gate":
                 c = models.Circuit(3)
                 c.add(measurement.on_qubits({0: 0, 1: 2}))
                 assert c.queue[0].result is measurement.result
-                print(c.draw())
+                c.draw()
             .. testoutput::
 
                 q0: ─M─

src/qibo/models/circuit.py

@@ -1,5 +1,6 @@
 import collections
 import copy
+import sys
 from typing import Dict, List, Optional, Tuple, Union
 
 import numpy as np
@@ -1267,18 +1268,7 @@ def _update_draw_matrix(self, matrix, idx, gate, gate_symbol=None):
 
         return matrix, idx
 
-    def draw(self, line_wrap=70, legend=False) -> str:
-        """Draw text circuit using unicode symbols.
-
-        Args:
-            line_wrap (int): maximum number of characters per line. This option
-                split the circuit text diagram in chunks of line_wrap characters.
-            legend (bool): If ``True`` prints a legend below the circuit for
-                callbacks and channels. Default is ``False``.
-
-        Return:
-            String containing text circuit diagram.
-        """
+    def __str__(self, line_wrap: int = 70, legend: bool = False) -> str:
         # build string representation of gates
         matrix = [[] for _ in range(self.nqubits)]
         idx = [0] * self.nqubits
@@ -1369,3 +1359,40 @@ def chunkstring(string, length):
             output += table
 
         return output.rstrip("\n")
+
+    def draw(self, line_wrap: int = 70, legend: bool = False):
+        """Draw text circuit using unicode symbols.
+
+        Args:
+            line_wrap (int, optional): maximum number of characters per line. This option
+                split the circuit text diagram in chunks of line_wrap characters.
+                Defaults to :math:`70`.
+            legend (bool, optional): If ``True`` prints a legend below the circuit for
+                callbacks and channels. Defaults to ``False``.
+
+        Returns:
+            String containing text circuit diagram.
+        """
+        qibo.config.log.warning(
+            "Starting on qibo 0.2.13, ``Circuit.draw`` will work in-place. "
+            + "The in-place method is currently implemented as ``Circuit.display``, but "
+            + "will be renamed as ``Circuit.draw`` on release 0.2.13. "
+            + "In release 0.2.12, the in-place print of circuits is accessible as "
+            + "``Circuit._display``."
+        )
+        return self.__str__(line_wrap, legend)
+
+    def _display(self, line_wrap: int = 70, legend: bool = False):
+        """Draw text circuit using unicode symbols.
+
+        Args:
+            line_wrap (int, optional): maximum number of characters per line. This option
+                split the circuit text diagram in chunks of line_wrap characters.
+                Defaults to :math:`70`.
+            legend (bool, optional): If ``True`` prints a legend below the circuit for
+                callbacks and channels. Defaults to ``False``.
+
+        Returns:
+            String containing text circuit diagram.
+        """
+        sys.stdout.write(self.__str__(line_wrap, legend))

tests/conftest.py

@@ -14,9 +14,9 @@
     "numpy",
     "tensorflow",
     "pytorch",
-    "qibojit-numba",
-    "qibojit-cupy",
-    "qibojit-cuquantum",
+    # "qibojit-numba",
+    # "qibojit-cupy",
+    # "qibojit-cuquantum",
 ]
 # multigpu configurations to be tested (only with qibojit-cupy)
 ACCELERATORS = [

tests/test_measurements.py

@@ -442,7 +442,7 @@ def test_measurement_basis_list(backend):
     result = backend.execute_circuit(c, nshots=100)
     assert result.frequencies() == {"0011": 100}
     assert (
-        c.draw()
+        c.draw(output_string=True)
         == """q0: ─H─H───M─
 q1: ───────M─
 q2: ─X─H─H─M─

tests/test_models_circuit.py

@@ -634,7 +634,7 @@ def test_circuit_draw():
     circuit.add(gates.SWAP(0, 4))
     circuit.add(gates.SWAP(1, 3))
 
-    assert circuit.draw() == ref
+    assert circuit.draw(output_string=True) == ref
 
 
 def test_circuit_wire_names_errors():
@@ -667,7 +667,7 @@ def test_circuit_draw_wire_names():
     circuit.add(gates.SWAP(0, 4))
     circuit.add(gates.SWAP(1, 3))
 
-    assert circuit.draw() == ref
+    assert circuit.draw(output_string=True) == ref
 
 
 def test_circuit_draw_line_wrap():
@@ -723,8 +723,8 @@ def test_circuit_draw_line_wrap():
     circuit.add(gates.GeneralizedfSim(0, 2, np.eye(2), 0))
     circuit.add(gates.X(4).controlled_by(1, 2, 3))
     circuit.add(gates.M(*range(3)))
-    assert circuit.draw(line_wrap=50) == ref_line_wrap_50
-    assert circuit.draw(line_wrap=30) == ref_line_wrap_30
+    assert circuit.draw(line_wrap=50, output_string=True) == ref_line_wrap_50
+    assert circuit.draw(line_wrap=30, output_string=True) == ref_line_wrap_30
 
 
 def test_circuit_draw_line_wrap_names():
@@ -780,8 +780,8 @@ def test_circuit_draw_line_wrap_names():
     circuit.add(gates.GeneralizedfSim(0, 2, np.eye(2), 0))
     circuit.add(gates.X(4).controlled_by(1, 2, 3))
     circuit.add(gates.M(*range(3)))
-    assert circuit.draw(line_wrap=50) == ref_line_wrap_50
-    assert circuit.draw(line_wrap=30) == ref_line_wrap_30
+    assert circuit.draw(line_wrap=50, output_string=True) == ref_line_wrap_50
+    assert circuit.draw(line_wrap=30, output_string=True) == ref_line_wrap_30
 
 
 @pytest.mark.parametrize("legend", [True, False])
@@ -814,7 +814,7 @@ def test_circuit_draw_channels(legend):
             "| PauliNoiseChannel   | PN       |"
         )
 
-    assert circuit.draw(legend=legend) == ref
+    assert circuit.draw(legend=legend, output_string=True) == ref
 
 
 @pytest.mark.parametrize("legend", [True, False])
@@ -840,7 +840,7 @@ def test_circuit_draw_callbacks(legend):
             "| EntanglementEntropy | EE       |"
         )
 
-    assert c.draw(legend=legend) == ref
+    assert c.draw(legend=legend, output_string=True) == ref
 
 
 def test_circuit_draw_labels():
@@ -861,10 +861,10 @@ def test_circuit_draw_labels():
             circuit.add(gate)
     circuit.add(gates.SWAP(0, 4))
     circuit.add(gates.SWAP(1, 3))
-    assert circuit.draw() == ref
+    assert circuit.draw(output_string=True) == ref
 
 
-def test_circuit_draw_names():
+def test_circuit_draw_names(capsys):
     """Test circuit text draw."""
     ref = (
         "q0: ─H─cx─cx─cx─cx───────────────────────────x───\n"
@@ -882,7 +882,12 @@ def test_circuit_draw_names():
             circuit.add(gate)
     circuit.add(gates.SWAP(0, 4))
     circuit.add(gates.SWAP(1, 3))
-    assert circuit.draw() == ref
+    assert circuit.draw(output_string=True) == ref
+
+    # Testing circuit text draw when ``output_string == False``
+    circuit._display()
+    out, _ = capsys.readouterr()
+    assert out == ref
 
 
 def test_circuit_draw_error():
@@ -894,4 +899,4 @@ def test_circuit_draw_error():
     circuit.add(error_gate)
 
     with pytest.raises(NotImplementedError):
-        circuit.draw()
+        circuit.draw(output_string=True)

tests/test_models_circuit_fuse.py

@@ -236,4 +236,4 @@ def test_fused_gate_draw():
     circuit.add(gates.SWAP(0, 4))
     circuit.add(gates.SWAP(1, 3))
     circuit = circuit.fuse()
-    assert circuit.draw() == ref
+    assert circuit.draw(output_string=True) == ref

tests/test_noise.py

@@ -758,7 +758,9 @@ def test_ibmq_noise(
 
     noisy_circuit_target = noise_model_target.apply(circuit)
 
-    assert noisy_circuit.draw() == noisy_circuit_target.draw()
+    assert noisy_circuit.draw(output_string=True) == noisy_circuit_target.draw(
+        output_string=True
+    )
 
     backend.set_seed(2024)
     state = backend.execute_circuit(noisy_circuit, nshots=10)