Fix get_sparse_operator to handle unsimplified QubitOperator

Author: Aniketsy

src/openfermion/linalg/sparse_tools.py

@@ -12,13 +12,13 @@
 """This module provides functions to interface with scipy.sparse."""
 import itertools
 from functools import reduce
+import warnings
 import numpy.linalg
 import numpy
 
 import scipy
 import scipy.sparse
 import scipy.sparse.linalg
-import warnings
 
 from openfermion.ops.operators import FermionOperator, QubitOperator, BosonOperator, QuadOperator
 from openfermion.ops.representations import DiagonalCoulombHamiltonian, PolynomialTensor
@@ -1273,9 +1273,9 @@ def get_sparse_operator(operator, n_qubits=None, trunc=None, hbar=1.0):
             operator.simplify()
         else:
             warnings.warn(
-            "QubitOperator.simplify() not found. "
-            "Ensure your operator is simplified to avoid errors."
-        )
+                "QubitOperator.simplify() not found. "
+                "Ensure your operator is simplified to avoid errors."
+            )
         return qubit_operator_sparse(operator, n_qubits)
     elif isinstance(operator, (BosonOperator, QuadOperator)):
         return boson_operator_sparse(operator, trunc, hbar)