QuantumCircuit.draw(output='mpl') does not show circuit plots if called in a loop in Jupyter notebook

[sgeaney-oqc]

Informations

• Qiskit version:: 0.34.2
• Qiskit Aer version:: 0.10.3
• Python version: Python 3.8.0
• Operating system: Windows 10, 64-bit

What is the current behaviour?

Generate some simple circuits in qiskit, put these circuits into a list and then in a for loop, try to draw each circuit. Snippet below: circ_inputs = [qc1, qc2, qc3, qc4] for i, circuit in enumerate(circ_inputs): circuit.draw(output='mpl')

Using the show() method in the loop: import matplotlib.pyplot as plt plt.show()

Does not resolve the issue as suggested in some qiskit issue posts.

Steps to reproduce the problem

1. Create more than one quantum circuit in qiskit (four circuits were made in the example above).
2. In a Jupyter notebook, use the QuantumCircuits.draw(output='mpl') method in a loop.
3. Make sure to use the output='mpl' flag.
4. Run the cell.
5. Not plot will be produced. However, if one circuit is drawn out of the loop, it will be shown.

What is the expected behaviour?

In the above example, 4 plots should be shown, preferably one on top of the other.

Suggested solutions

May need a new implementation but returning the axes objects in some way from the 'QuantumCircuit' object method so that they can each be drawn in a loop.

[enavarro51]

At least on the jupyter backend I use, you can wrap the draw command with the jupyter display command to see all 4 outputs. This works whether using 'mpl', 'text', or 'latex'.

display(circuit.draw('mpl'))

[sgeaney-oqc]

Yep, that seems to solve the issue. Thanks, @enavarro51!

[Hussanulmaab]

At least on the jupyter backend I use, you can wrap the draw command with the jupyter display command to see all 4 outputs. This works whether using 'mpl', 'text', or 'latex'.

display(circuit.draw('mpl'))

Thank you