Pandas: Group by calendar-week, then plot grouped barplots for the real datetime

Question

EDIT

I found a quite nice solution and posted it below as an answer. The result will look like this:

Answer 1

Add the week to 52 times the year, so that weeks are ordered "by year". Set the tick labels back, which might be nontrivial, to what you want.

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What you want is for the weeks to increase like so

nth week → (n+1)th week → (n+2)th week → etc.

but when you have a new year it instead falls by 51 (52 → 1).

To offset this, note that the year increases by one. So add the year's increase multiplied by 52 and the total change will be -51 + 52 = 1 as wanted.