Written by Mia von Steinkirch

QC Sandbox is a platform to help software engineers and quantum computing enthusiasts learn quantum software languages, through interactive coding tutorials, curated articles, and quantum games.

In this very simple *hello world* example, you will learn how to create a qubit and a circuit in one of the open-source quantum software languages available: Google's Cirq.

Create a qubit:

```
import cirq
msg = cirq.LineQubit(0)
```

Create a circuit and add your qubit:

```
circuit = cirq.Circuit()
circuit.append(cirq.X(msg))
print(circuit)
```

Run the simulator and measure the qubit:

```
import numpy as np
sim = cirq.Simulator()
original_message = sim.simulate(circuit)
expected = cirq.bloch_vector_from_state_vector(original_message.final_state, 0)
print("\nBloch Sphere of Message After X Gate:")
print("x: ", np.around(expected[0], 4), "y: ", np.around(expected[1], 4),
"z: ", np.around(expected[2], 4))
```