Pad results with zeros for unmeasured states

What is the expected enhancement?

After executing a job on qiskit, the typically procedure to get the measurement data from the quantum computer is to call get_counts() like so…

job = execute(qc, backend, shots=100)
result = job.result()
counts = result.get_counts()

If the final state is, for example, $| 01 \rangle$ then ‘01’ would be the only key in counts. For some analyses, it would be very useful if the returned counts dictionary had 0s for all the states that were not measured. Maybe something like counts = results.get_counts(pad=True), and counts would then be counts = {'00':0, '01':100, '10':0, '11':0}

[jakelishman]

If you try to get valid bitstrings from it, it will return 0 if no counts were seen (and obviously return the correct number if the state was seen). You wouldn’t need an option for it to work; it’d do it by default. Things like print(counts) won’t show the 0s, though - that would involve the exponential behaviour that we can’t safely include.

[ajrazander]

Ah ok, I see now. Yes, that behavior is even better! Thank you!