[Python-Dev] transitioning from % to {} formatting (original) (raw)

Carl Trachte ctrachte at gmail.com
Fri Oct 2 22:23:11 CEST 2009

Do the users get any say in this? I'm a user! :-) I hate calling methods on string literals, I think it looks very odd to have code like this: "Displaying {0} of {1} revisions".format(x, y) Will we be able to write this as "Displaying {0} of {1} revisions" % (x, y) too?

I imagine that some people are heavily invested in %-formatting.

Because there has been limited uptake on {}-formatting (afaict), we still have limited experience with knowing that it is actually better, less error-prone, easier to learn/rember, etc. Outside a handful of people on this list, I have yet to see anyone adopt it as the preferred syntax. I've skimmed over the PEP, and the new {}-syntax seems to have some nice features. But I've not seen it used anywhere yet.

Rami Chowdhury posted this to a mailing list; I've been using it (perhaps unintentionally promoting it) as part of non-English, non-ASCII font outreach:

def শালামবল(নাম): কথা = "শালাম {0}. কেমন আছেন?".format(নাম) print(কথা)

def saygreeting(name): tosay = "Greetings, {0}. How are you?".format(name) print(tosay)

As a user, my assumption was {} was going forward, rain or shine, and everyone should be on board by Python 3.2. (I thought once the Talin PEP got approved, that was it). I wrote Steven Bethard privately about this.

Sorry for the intrusion.

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