I am just running
replace.py -catr:%D0%92%D0%B5%D0%BD%D0%B3%D1%80%D0%B8%D1%8F . @ -lang:ru -excepttext:"[[hu:" -save:magyarok.txt -always to collect Hungary-related articles from Russian Wikipedia.
This stuff has already been running for 10 hours mostly because of pywikibot.output. When the overwhelming majority of characters appears as yellow (substituted), this function slows down the program extremely. I see it writing text on my screen character by character.

This gives me the idea to introduce a new switch: -silent.
From line 474 on
          # Show the title of the page we're working on.
          # Highlight the title in purple.
          pywikibot.output(u"\n\n>>> \03{lightpurple}%s\03{default} <<<"
                           % page.title())
          pywikibot.showDiff(original_text, new_text)
should not be executed with this switch on. This is recommended only for such cases as mentioned above.

Because this can be dangereous, there could be a restriction that allows this switch to work only together with -always.
OR, an even more restrictive rule: it can work only with -save/savenew (one could argue that any work on live wiki should appear on the screen).

Which one is better?