4 ms·

What makes me snarky is the replacing of '%s %s' % ('one', 'two') With '%s %s'.format('one', 'two') The latter is just more annoying to type. Stupid

• davidism 11y ago
  It's not replaced, both are perfectly valid. And this addition also exists in Python 2.
• RussianCow 11y ago
  The second example should be: '{} {}'.format('one', 'two') Either way, the former example still works in Python 3.5, so that syntax hasn't gone away. `format` is preferred, though. This Stack Overflow question has some good answers as to why: http://stackoverflow.com/questions/5082452/python-string-formatting-vs-format http://stackoverflow.com/questions/5082452/python-string-for...
• dietrichepp 11y ago
  You mean, '{} {}'.format('one', 'two') Your experience may vary, but in my experience, when I switched to .format(), I found a number of bugs in code that used % instead. As mentioned, you can continue using %.
  • teach 11y ago
    I had the same experience. I love love love printf() and it's ilk, so switching to something else (no matter how well designed) seemed asinine at first. But .format() has really started to grow on me and did uncover some subtle bugs in old code.
• gluelogic 11y ago
  The thing about the latter form is that you can do something like '{0} {1} {0} {2}'.format('apple', 'banana', 'orange') which results in 'apple banana apple orange'
  • squeaky-clean 11y ago
    You can also use keyword arguments, which is really helpful in certain situation. Example from the docs: 'Coordinates: {latitude}, {longitude}'.format(latitude='37.24N', longitude='-115.81W')
    • wyldfire 11y ago
      You could do that before with % substitution too. But I prefer .format() because (1) it's the new idiom and (2) will coerce to string without me binding the type in the format string.
• mixmastamyk 11y ago
  Simplified to this in Py 3.6: f'{one} {two}'
  • teddyh 11y ago
    Do you have a reference for that? Wouldn’t that be introducing a huge security hole in all programs?
    • mixmastamyk 11y ago
      PEP 498. Literals only, does not add any additional security problems.
      • teddyh 11y ago
        Ah, right; I missed the ‘f’ prefix. And since it’s only done when parsing the expression, it is not a security problem. Thanks!
  • kazagistar 11y ago
    Is it actually happening? Proper string interpolation? In all its extendable glory?
    • mixmastamyk 11y ago
      Pep was accepted, and I believe can be tried in a nightly or alpha release. It is not extensible though, GvR didn't see much utility, yet at least.
• frewsxcv 11y ago
  Let's not also forget string.Template ;) https://docs.python.org/2/library/string.html#string.Template https://docs.python.org/2/library/string.html#string.Templat...
  • sevensor 11y ago
    I actually found a good use for string.Template, but that doesn't mean I understand why it exists in addition to the other two formatting sub-languages.
    • mixmastamyk 11y ago
      It was created long before .format and is better in some cases for i18n where simplicity is best.
• andreasvc 11y ago
  No need to get snarky, because the % formatting is still in Python 3. It is also my preferred formatting method.
• RodericDay 11y ago
  The super, super controversial automatic interpolation feature is what I'm really looking forward to.