From QUBO matrix to Ising model in Qiskit

I prepared this code based on Qiskit tutorial. Firstly, lets prepare a QUBO task.

# Importing standard Qiskit libraries and configuring account
from qiskit import QuantumCircuit, execute, Aer, IBMQ
from qiskit.compiler import transpile, assemble
from qiskit.tools.jupyter import *
from qiskit.visualization import *
#quadratic optimization
from qiskit.optimization import QuadraticProgram
from qiskit.optimization.converters import QuadraticProgramToQubo

# Prepare QUBO task

#prepare quadratic binary optimization task
task = QuadraticProgram(name = 'QUBO on QC')
task.binary_var(name = 'x')
task.binary_var(name = 'y')
task.binary_var(name = 'z')
task.minimize(linear = [1,-2,3], quadratic = [[0,0.5,-0.5],[0.5,0,1],[-0.5,1,0]])
qubo = QuadraticProgramToQubo().convert(task) #convert to QUBO
print(qubo.export_as_lp_string())

Now, we have a QUBO task and you can convert it to Ising Hamiltonian with this code:

#converting QUBO task to Ising Hamiltonian for simulation on quantum computer
operator, offset = qubo.to_ising()

#operator - unitary operator representing the simulated Hamiltonian
#offset - used after solution on QC to convert objective function value to the proper one

print(operator)

This code converts Ising Hamiltonian to QUBO:

#conversion of Ising Hamiltonian to QUBO
qp = QuadraticProgram()
qp.from_ising(operator, offset, linear = True) #linear=True => x^2 is shown as x since x^2=x for x in {0,1}
print(qp.export_as_lp_string())