Add units to checked values

[jazzzz]

For large values, Cabot status messages can be hard to read (like "16360927232.0 < 100000000000.0"). It would be nice to set a unit to the checked metrics and use it to humanize displayed values (like Grafana for example).

[dbuxton]

I guess an initial implementation of this could be as simple as defining an optional format string in Python syntax? So a value of 13252352.304 and format string of %.2e would result in 1.33e+07.

[jazzzz]

A format string would be better than nothing, but it's still harder to read "13252352" against "3 hours, 40 minutes, 52.352 seconds".

[dbuxton]

Point taken - what would be the most important types then in your opinion?

In terms of otherwise unreadable, I guess:

• data size (i.e. MB/GB etc)
• data rate (MB/s)
• time

Other units seem like they are less of an issue to me.

[jazzzz]

This would cover most (if not all) my needs!

[hartwork]

You're considering to add support of user controlled format strings, right? I would like to point out potential security implications, e.g. when using .format: http://lucumr.pocoo.org/2016/12/29/careful-with-str-format/.