chore: Run pre-commit on all files

setup.py

@@ -1,6 +1,7 @@
-from setuptools import setup, find_packages
-import re
 import pathlib
+import re
+
+from setuptools import find_packages, setup
 
 HERE = pathlib.Path(__file__).parent.absolute()
 PACKAGE = "qibotn"
@@ -8,8 +9,8 @@ PACKAGE = "qibotn"
 
 # Returns the qibotn version
 def version():
-    """Gets the version from the package's __init__ file
+    """Gets the version from the package's __init__ file if there is some
-    if there is some problem, let it happily fail"""
+    problem, let it happily fail."""
     version_file = HERE / "src" / PACKAGE / "__init__.py"
     version_regex = r"^__version__ = ['\"]([^'\"]*)['\"]"
 

src/qibotn/MPSUtils.py

@@ -1,23 +1,19 @@
 import cupy as cp
-from cuquantum.cutensornet.experimental import contract_decompose
 from cuquantum import contract
+from cuquantum.cutensornet.experimental import contract_decompose
 
 # Reference: https://github.com/NVIDIA/cuQuantum/blob/main/python/samples/cutensornet/tn_algorithms/mps_algorithms.ipynb
 
 
 def initial(num_qubits, dtype):
-    """
+    """Generate the MPS with an initial state of |00...00>"""
-    Generate the MPS with an initial state of |00...00>
-    """
     state_tensor = cp.asarray([1, 0], dtype=dtype).reshape(1, 2, 1)
     mps_tensors = [state_tensor] * num_qubits
     return mps_tensors
 
 
 def mps_site_right_swap(mps_tensors, i, **kwargs):
-    """
+    """Perform the swap operation between the ith and i+1th MPS tensors."""
-    Perform the swap operation between the ith and i+1th MPS tensors.
-    """
     # contraction followed by QR decomposition
     a, _, b = contract_decompose(
         "ipj,jqk->iqj,jpk",
@@ -30,8 +26,7 @@ def mps_site_right_swap(mps_tensors, i, **kwargs):
 
 
 def apply_gate(mps_tensors, gate, qubits, **kwargs):
-    """
+    """Apply the gate operand to the MPS tensors in-place.
-    Apply the gate operand to the MPS tensors in-place.
 
     Args:
         mps_tensors: A list of rank-3 ndarray-like tensor objects.

src/qibotn/QiboCircuitConvertor.py

@@ -5,9 +5,9 @@ import numpy as np
 
 
 class QiboCircuitToEinsum:
-    """Convert a circuit to a Tensor Network (TN) representation.
+    """Convert a circuit to a Tensor Network (TN) representation. The circuit
-    The circuit is first processed to an intermediate form by grouping each gate
+    is first processed to an intermediate form by grouping each gate matrix
-    matrix with its corresponding qubit it is acting on to a list. It is then
+    with its corresponding qubit it is acting on to a list. It is then
     converted to an equivalent TN expression through the class function
     state_vector_operands() following the Einstein summation convention in the
     interleave format.
@@ -79,9 +79,8 @@ class QiboCircuitToEinsum:
         return mode_labels, operands
 
     def op_shape_from_qubits(self, nqubits):
-        """Modify tensor to cuQuantum shape
+        """Modify tensor to cuQuantum shape (qubit_states,input_output) *
-        (qubit_states,input_output) * qubits_involved
+        qubits_involved."""
-        """
         return (2, 2) * nqubits
 
     def init_intermediate_circuit(self, circuit):
@@ -134,8 +133,7 @@ class QiboCircuitToEinsum:
         self.active_qubits_inverse = np.unique(gates_qubits_inverse)
 
     def get_pauli_gates(self, pauli_map, dtype="complex128", backend=cp):
-        """
+        """Populate the gates for all pauli operators.
-        Populate the gates for all pauli operators.
 
         Args:
             pauli_map: A dictionary mapping qubits to pauli operators.

src/qibotn/QiboCircuitToMPS.py

@@ -1,9 +1,9 @@
 import cupy as cp
 import numpy as np
-
 from cuquantum import cutensornet as cutn
+
+from qibotn.MPSUtils import apply_gate, initial
 from qibotn.QiboCircuitConvertor import QiboCircuitToEinsum
-from qibotn.MPSUtils import initial, apply_gate
 
 
 class QiboCircuitToMPS:

src/qibotn/backends/__init__.py

@@ -1,2 +1,2 @@
-from qibotn.backends.gpu import CuTensorNet
 from qibotn.backends.cpu import QuTensorNet
+from qibotn.backends.gpu import CuTensorNet

src/qibotn/backends/gpu.py

@@ -1,8 +1,7 @@
 import numpy as np
-
 from qibo.backends.numpy import NumpyBackend
-from qibo.states import CircuitResult
 from qibo.config import raise_error
+from qibo.states import CircuitResult
 
 
 class CuTensorNet(NumpyBackend):  # pragma: no cover
@@ -107,7 +106,6 @@ class CuTensorNet(NumpyBackend):  # pragma: no cover
 
         Returns:
             xxx.
-
         """
 
         import qibotn.eval as eval

src/qibotn/eval.py

@@ -1,20 +1,22 @@
-from qibotn.QiboCircuitConvertor import QiboCircuitToEinsum
-from cuquantum import contract
-from cupy.cuda.runtime import getDeviceCount
 import cupy as cp
+from cupy.cuda.runtime import getDeviceCount
+from cuquantum import contract
 
-from qibotn.QiboCircuitToMPS import QiboCircuitToMPS
 from qibotn.mps_contraction_helper import MPSContractionHelper
+from qibotn.QiboCircuitConvertor import QiboCircuitToEinsum
+from qibotn.QiboCircuitToMPS import QiboCircuitToMPS
 
 
 def dense_vector_tn(qibo_circ, datatype):
-    """Convert qibo circuit to tensornet (TN) format and perform contraction to dense vector."""
+    """Convert qibo circuit to tensornet (TN) format and perform contraction to
+    dense vector."""
     myconvertor = QiboCircuitToEinsum(qibo_circ, dtype=datatype)
     return contract(*myconvertor.state_vector_operands())
 
 
 def expectation_pauli_tn(qibo_circ, datatype, pauli_string_pattern):
-    """Convert qibo circuit to tensornet (TN) format and perform contraction to expectation of given Pauli string."""
+    """Convert qibo circuit to tensornet (TN) format and perform contraction to
+    expectation of given Pauli string."""
     myconvertor = QiboCircuitToEinsum(qibo_circ, dtype=datatype)
     return contract(
         *myconvertor.expectation_operands(
@@ -24,14 +26,19 @@ def expectation_pauli_tn(qibo_circ, datatype, pauli_string_pattern):
 
 
 def dense_vector_tn_MPI(qibo_circ, datatype, n_samples=8):
-    """Convert qibo circuit to tensornet (TN) format and perform contraction using multi node and multi GPU through MPI.
+    """Convert qibo circuit to tensornet (TN) format and perform contraction
-    The conversion is performed by QiboCircuitToEinsum(), after which it goes through 2 steps: pathfinder and execution.
+    using multi node and multi GPU through MPI.
-    The pathfinder looks at user defined number of samples (n_samples) iteratively to select the least costly contraction path. This is sped up with multi thread.
+
-    After pathfinding the optimal path is used in the actual contraction to give a dense vector representation of the TN.
+    The conversion is performed by QiboCircuitToEinsum(), after which it
+    goes through 2 steps: pathfinder and execution. The pathfinder looks
+    at user defined number of samples (n_samples) iteratively to select
+    the least costly contraction path. This is sped up with multi
+    thread. After pathfinding the optimal path is used in the actual
+    contraction to give a dense vector representation of the TN.
     """
 
-    from mpi4py import MPI
     from cuquantum import Network
+    from mpi4py import MPI
 
     root = 0
     comm = MPI.COMM_WORLD
@@ -86,14 +93,19 @@ def dense_vector_tn_MPI(qibo_circ, datatype, n_samples=8):
 
 
 def dense_vector_tn_nccl(qibo_circ, datatype, n_samples=8):
-    """Convert qibo circuit to tensornet (TN) format and perform contraction using multi node and multi GPU through NCCL.
+    """Convert qibo circuit to tensornet (TN) format and perform contraction
-    The conversion is performed by QiboCircuitToEinsum(), after which it goes through 2 steps: pathfinder and execution.
+    using multi node and multi GPU through NCCL.
-    The pathfinder looks at user defined number of samples (n_samples) iteratively to select the least costly contraction path. This is sped up with multi thread.
+
-    After pathfinding the optimal path is used in the actual contraction to give a dense vector representation of the TN.
+    The conversion is performed by QiboCircuitToEinsum(), after which it
+    goes through 2 steps: pathfinder and execution. The pathfinder looks
+    at user defined number of samples (n_samples) iteratively to select
+    the least costly contraction path. This is sped up with multi
+    thread. After pathfinding the optimal path is used in the actual
+    contraction to give a dense vector representation of the TN.
     """
-    from mpi4py import MPI
-    from cuquantum import Network
     from cupy.cuda import nccl
+    from cuquantum import Network
+    from mpi4py import MPI
 
     root = 0
     comm_mpi = MPI.COMM_WORLD
@@ -159,15 +171,22 @@ def dense_vector_tn_nccl(qibo_circ, datatype, n_samples=8):
 
 
 def expectation_pauli_tn_nccl(qibo_circ, datatype, pauli_string_pattern, n_samples=8):
-    """Convert qibo circuit to tensornet (TN) format and perform contraction to expectation of given Pauli string using multi node and multi GPU through NCCL.
+    """Convert qibo circuit to tensornet (TN) format and perform contraction to
-    The conversion is performed by QiboCircuitToEinsum(), after which it goes through 2 steps: pathfinder and execution.
+    expectation of given Pauli string using multi node and multi GPU through
-    The pauli_string_pattern is used to generate the pauli string corresponding to the number of qubits of the system.
+    NCCL.
-    The pathfinder looks at user defined number of samples (n_samples) iteratively to select the least costly contraction path. This is sped up with multi thread.
+
-    After pathfinding the optimal path is used in the actual contraction to give an expectation value.
+    The conversion is performed by QiboCircuitToEinsum(), after which it
+    goes through 2 steps: pathfinder and execution. The
+    pauli_string_pattern is used to generate the pauli string
+    corresponding to the number of qubits of the system. The pathfinder
+    looks at user defined number of samples (n_samples) iteratively to
+    select the least costly contraction path. This is sped up with multi
+    thread. After pathfinding the optimal path is used in the actual
+    contraction to give an expectation value.
     """
-    from mpi4py import MPI
-    from cuquantum import Network
     from cupy.cuda import nccl
+    from cuquantum import Network
+    from mpi4py import MPI
 
     root = 0
     comm_mpi = MPI.COMM_WORLD
@@ -235,14 +254,21 @@ def expectation_pauli_tn_nccl(qibo_circ, datatype, pauli_string_pattern, n_sampl
 
 
 def expectation_pauli_tn_MPI(qibo_circ, datatype, pauli_string_pattern, n_samples=8):
-    """Convert qibo circuit to tensornet (TN) format and perform contraction to expectation of given Pauli string using multi node and multi GPU through MPI.
+    """Convert qibo circuit to tensornet (TN) format and perform contraction to
-    The conversion is performed by QiboCircuitToEinsum(), after which it goes through 2 steps: pathfinder and execution.
+    expectation of given Pauli string using multi node and multi GPU through
-    The pauli_string_pattern is used to generate the pauli string corresponding to the number of qubits of the system.
+    MPI.
-    The pathfinder looks at user defined number of samples (n_samples) iteratively to select the least costly contraction path. This is sped up with multi thread.
+
-    After pathfinding the optimal path is used in the actual contraction to give an expectation value.
+    The conversion is performed by QiboCircuitToEinsum(), after which it
+    goes through 2 steps: pathfinder and execution. The
+    pauli_string_pattern is used to generate the pauli string
+    corresponding to the number of qubits of the system. The pathfinder
+    looks at user defined number of samples (n_samples) iteratively to
+    select the least costly contraction path. This is sped up with multi
+    thread. After pathfinding the optimal path is used in the actual
+    contraction to give an expectation value.
     """
-    from mpi4py import MPI  # this line initializes MPI
     from cuquantum import Network
+    from mpi4py import MPI  # this line initializes MPI
 
     root = 0
     comm = MPI.COMM_WORLD
@@ -299,7 +325,8 @@ def expectation_pauli_tn_MPI(qibo_circ, datatype, pauli_string_pattern, n_sample
 
 
 def dense_vector_mps(qibo_circ, gate_algo, datatype):
-    """Convert qibo circuit to matrix product state (MPS) format and perform contraction to dense vector."""
+    """Convert qibo circuit to matrix product state (MPS) format and perform
+    contraction to dense vector."""
     myconvertor = QiboCircuitToMPS(qibo_circ, gate_algo, dtype=datatype)
     mps_helper = MPSContractionHelper(myconvertor.num_qubits)
 
@@ -309,7 +336,9 @@ def dense_vector_mps(qibo_circ, gate_algo, datatype):
 
 
 def pauli_string_gen(nqubits, pauli_string_pattern):
-    """Used internally to generate the string based on given pattern and number of qubit.
+    """Used internally to generate the string based on given pattern and number
+    of qubit.
+
     Example: pattern: "XZ", number of qubit: 7, output = XZXZXZX
     """
     if nqubits <= 0:

src/qibotn/mps_contraction_helper.py

@@ -1,11 +1,10 @@
-from cuquantum import contract, contract_path, CircuitToEinsum, tensor
+from cuquantum import contract, contract_path
 
 # Reference: https://github.com/NVIDIA/cuQuantum/blob/main/python/samples/cutensornet/tn_algorithms/mps_algorithms.ipynb
 
 
 class MPSContractionHelper:
-    """
+    """A helper class to compute various quantities for a given MPS.
-    A helper class to compute various quantities for a given MPS.
 
     Interleaved format is used to construct the input args for `cuquantum.contract`.
     A concrete example on how the modes are populated for a 7-site MPS is provided below:
@@ -43,8 +42,8 @@ class MPSContractionHelper:
         ]
 
     def contract_norm(self, mps_tensors, options=None):
-        """
+        """Contract the corresponding tensor network to form the norm of the
-        Contract the corresponding tensor network to form the norm of the MPS.
+        MPS.
 
         Args:
             mps_tensors: A list of rank-3 ndarray-like tensor objects.
@@ -64,8 +63,8 @@ class MPSContractionHelper:
         return self._contract(interleaved_inputs, options=options).real
 
     def contract_state_vector(self, mps_tensors, options=None):
-        """
+        """Contract the corresponding tensor network to form the state vector
-        Contract the corresponding tensor network to form the state vector representation of the MPS.
+        representation of the MPS.
 
         Args:
             mps_tensors: A list of rank-3 ndarray-like tensor objects.
@@ -86,8 +85,8 @@ class MPSContractionHelper:
     def contract_expectation(
         self, mps_tensors, operator, qubits, options=None, normalize=False
     ):
-        """
+        """Contract the corresponding tensor network to form the expectation of
-        Contract the corresponding tensor network to form the expectation of the MPS.
+        the MPS.
 
         Args:
             mps_tensors: A list of rank-3 ndarray-like tensor objects.

tests/test_cuquantum_cutensor_backend.py

@@ -1,8 +1,8 @@
 from timeit import default_timer as timer
 
 import config
-import numpy as np
 import cupy as cp
+import numpy as np
 import pytest
 import qibo
 from qibo.models import QFT