Adding docstring to quimb.py and eval_qu.py

src/qibotn/backends/quimb.py

@@ -59,7 +59,7 @@ class QuimbBackend(NumpyBackend):
                 If ``None`` the default ``|00...0>`` state is used.
 
         Returns:
-            xxx.
+            list: Final state in the dense vector form after simulation of the circuit.
         """
 
         import qibotn.eval_qu as eval

src/qibotn/eval_qu.py

@@ -3,7 +3,15 @@ import quimb.tensor as qtn
 
 
 def init_state_tn(nqubits, init_state_sv):
-    """Create a matrix product state directly from a dense vector."""
+    """Create a matrix product state directly from a dense vector.
+
+        Args:
+            nqubits (int): Total number of qubits in the circuit.
+            init_state_sv (list): Initial state in the dense vector form.
+
+        Returns:
+            list: Matrix product state representation of the dense vector.
+    """
 
     dims = tuple(2 * np.ones(nqubits, dtype=int))
 
@@ -11,9 +19,17 @@ def init_state_tn(nqubits, init_state_sv):
 
 
 def dense_vector_tn_qu(qasm: str, initial_state, mps_opts, backend="numpy"):
-    """Evaluate QASM with Quimb.
+    """Evaluate circuit in QASM format with Quimb.
+
+        Args:
+            qasm (str): QASM program.
+            initial_state (list): Initial state in the dense vector form. If ``None`` the default ``|00...0>`` state is used.
+            mps_opts (dict): Parameters to tune the gate_opts for mps settings in ``class quimb.tensor.circuit.CircuitMPS``. 
+            backend (str):  Backend to perform the contraction with, e.g. ``numpy``, ``cupy``, ``jax``. Passed to ``opt_einsum``.
+
+        Returns:
+            list: Amplitudes of final state after the simulation of the circuit.
    
-    backend (quimb): numpy, cupy, jax. Passed to ``opt_einsum``.
     """
 
     if initial_state is not None: