Hacker News Reader

Comment by bubblesocks | Hacker News Reader

The nice thing about the new format is that you can reverse the order of the variables inside the string, which is nice when you're localizing strings into languages with a reversed sentence structures, like Japanese. I haven't done a ton of Python, but the old style won't let you do that, will it?

View on HN

Reversing the order is not possible, but you can use a dict instead:

    >>> "%(foo)s" % {"foo": "bar"}
    'bar'

Funny. I thought Python implemented all the quirks of the original printf() formatting, including using arguments at specific positions. Apparently it didn't (and arguably it's a good thing).

  $ printf '%2$s %2$s %1$s\n' aaa bbb
  bbb bbb aaa

Heyyyyyy I did not know that. TIL, thank you.

Yes, it will, just use named placeholders: "%(some)s" % {'some': 'helllo'}

I'm not sure I understand the use case for reversing the formatting variables, but you could do this to make old-style formatting work that way:

    >>> 'hello, %s %s' % tuple(reversed(['smith', 'bob']))
    'hello, bob smith'

I think it's more readable if you abstract that bit into a lambda function:

    >>> rev_args = lambda *args: tuple(reversed(args))
    >>> 'hello, %s %s' % rev_args('smith', 'bob')
    'hello, bob smith'

Reply on news.ycombinator.com