Allow silencing the 'Upgrading database` calls

[basnijholt]

I am processing and setting up >100.000 QCoDeS databases concurrently (in 256 threads). Every single time a new database is created I am presented with ≈10 lines like

Upgrading database; v6 -> v7: 0%| | 0/1 [00:00<?, ?it/s]

Eventually the output grew so large it crashed my browser 😅

I see that the progress bar just prints to stdout

https://github.com/QCoDeS/Qcodes/blob/fe24a9ac07659b4d8f9f13b2481ecdd76ea0d0fa/qcodes/dataset/sqlite/db_upgrades/__init__.py#L151

Ideally the verboseness of these upgrade should be configurable.

In the meantime, what is the recommended way to capture and trash this output? Just contextlib.redirect_stdout?

I have tried it with:

import os
import sys
import contextlib
import qcodes as qc

import tempfile

names = tempfile._get_candidate_names()

with open(os.devnull, 'w') as f, contextlib.redirect_stdout(f):
    with qc.initialised_database_at(f"/tmp/{next(names)}"):
        "Do the things here"

but this gives some tqdm errors :(

[jenshnielsen]

Are these new empty databases? It seems to me that the bar is only useful for dbs with existing data where the upgrade can be slow

[basnijholt]

Yes, here I am initializing new empty databases.

I agree that in this case it is not useful.