Display progress bars for long loops

[leo-desbureaux-tellae]

Some processes of Starling have long computation times.

In order to show progression over such loops, we could use tqdm to log a progress bar.

We should make sure this is compatible with the existing logging system of Starling (uses the logging library)

[leo-desbureaux-tellae]

About the compatibility with logging, I see two problems:

• Progress bar display is messed up if logs are displayed in the displayed loop

For this, we seem to have options to display logs using tqdm.write. So they take the place of the progress bar and are then replaced ?

See here: https://tqdm.github.io/docs/contrib.logging/

• The progress bar display should be conditioned to the same level logic than the basic logs. For instance, we would display a progress bar in INFO level, so it would not be displayed when set log level to WARN.

See here: https://stackoverflow.com/questions/14897756/python-progress-bar-through-logging-module/41224909#41224909
But it seems to display new lines instead of an updated progress bar.