Removing qml.load (#5654)

**Context:** ***Part of  deprecations and removals for pennylane-0.37***

**Description of the Change:** Removed `qml.load` in favor of more
specific functions.

[sc-62675]

doc/development/deprecations.rst

@@ -58,15 +58,14 @@ Other deprecations
   - Deprecated in v0.36
   - Will be removed in v0.37
 
+Completed deprecation cycles
+----------------------------
+
 * The ``qml.load`` function is a general-purpose way to convert circuits into PennyLane from other
-  libraries. It is being deprecated in favour of the more specific functions ``from_qiskit``,
-  ``from_qasm``, etc.
+  libraries. It has been removed in favour of the more specific functions ``from_qiskit``, ``from_qasm``, etc.
 
   - Deprecated in v0.36
-  - Will be removed in v0.37
-
-Completed deprecation cycles
-----------------------------
+  - Removed in v0.37
 
 * ``single_tape_transform``, ``batch_transform``, ``qfunc_transform``, ``op_transform``,
   ``gradient_transform`` and ``hessian_transform`` are deprecated. Instead switch to using the new

doc/releases/changelog-dev.md

@@ -65,6 +65,9 @@
 
 <h3>Breaking changes 💔</h3>
 
+* ``qml.load`` has been removed in favour of more specific functions, such as ``qml.from_qiskit``, etc.
+  [(#5654)](https://github.com/PennyLaneAI/pennylane/pull/5654)
+
 <h3>Deprecations 👋</h3>
 
 <h3>Documentation 📝</h3>

pennylane/io.py

@@ -40,71 +40,6 @@
 plugin_converters = {entry.name: entry for entry in __plugin_devices}
 
 
-def load(quantum_circuit_object, format: str, **load_kwargs):
-    r"""Load external quantum assembly and quantum circuits from supported frameworks
-    into PennyLane templates.
-
-    .. warning::
-        ``qml.load`` is deprecated. Instead, please use the functions outlined in the
-        :ref:`Importing Circuits <intro_ref_importing_circuits>` quickstart guide, such as ``qml.from_qiskit``.
-
-    .. note::
-
-        For more details on which formats are supported
-        please consult the corresponding plugin documentation:
-        https://pennylane.ai/plugins.html
-
-    **Example:**
-
-    >>> qc = qiskit.QuantumCircuit(2)
-    >>> qc.rz(0.543, [0])
-    >>> qc.cx(0, 1)
-    >>> my_circuit = qml.load(qc, format='qiskit')
-
-    The ``my_circuit`` template can now be used within QNodes, as a
-    two-wire quantum template.
-
-    >>> @qml.qnode(dev)
-    >>> def circuit(x):
-    >>>     qml.RX(x, wires=1)
-    >>>     my_circuit(wires=(1, 0))
-    >>>     return qml.expval(qml.Z(0))
-
-    Args:
-        quantum_circuit_object: the quantum circuit that will be converted
-            to a PennyLane template
-        format (str): the format of the quantum circuit object to convert from
-        **load_kwargs: keyword arguments to pass when converting the quantum circuit
-            using the plugin. See below for details about supported keyword arguments.
-
-    Keyword Args:
-        measurements (list[MeasurementProcess]): the list of PennyLane measurements that
-            overrides the terminal measurements that may be present in the imput circuit.
-            Currently, only supported for Qiskit's `QuantumCircuit <https://docs.pennylane.ai/projects/qiskit>`_.
-
-    Returns:
-        function: the PennyLane template created from the quantum circuit object
-
-    """
-
-    _format = "pyquil" if format == "pyquil_program" else format
-    warnings.warn(
-        f"qml.load() is deprecated. Instead, please use the more specific qml.from_{_format}()",
-        qml.PennyLaneDeprecationWarning,
-    )
-
-    if format in plugin_converters:
-        # loads the plugin load function
-        plugin_converter = plugin_converters[format].load()
-        # calls the load function of the converter on the quantum circuit object
-        return plugin_converter(quantum_circuit_object, **load_kwargs)
-
-    raise ValueError(
-        "Converter does not exist. Make sure the required plugin is installed "
-        "and supports conversion."
-    )
-
-
 def from_qiskit(quantum_circuit, measurements=None):
     r"""Converts a Qiskit `QuantumCircuit <https://docs.quantum.ibm.com/api/qiskit/qiskit.circuit.QuantumCircuit>`_
     into a PennyLane :ref:`quantum function <intro_vcirc_qfunc>`.

tests/test_io.py

@@ -73,13 +73,6 @@ def mock_plugin_converters_fixture(monkeypatch):
 class TestLoad:
     """Test that the convenience load functions access the correct entrypoint."""
 
-    def test_load_is_deprecated(self, monkeypatch):
-        """Test that qml.load is deprecated"""
-        mock_converter_dict = {entry: MockPluginConverter(entry) for entry in load_entry_points}
-        monkeypatch.setattr(qml.io, "plugin_converters", mock_converter_dict)
-        with pytest.warns(qml.PennyLaneDeprecationWarning, match="deprecated"):
-            _ = qml.load("test", format="qiskit")
-
     @pytest.mark.parametrize(
         "method, entry_point_name",
         [(qml.from_qiskit, "qiskit"), (qml.from_qiskit_op, "qiskit_op")],