Re: Using + with strings considered bad

Date	2015-04-29 06:40 -0500
From	Andrew Berg <aberg010@my.hennepintech.edu>
Subject	Re: Using + with strings considered bad
References	<878udbxrpg.fsf@Equus.decebal.nl> <mhq72r$jr9$1@ger.gmane.org>
Newsgroups	comp.lang.python
Message-ID	<mailman.89.1430331235.3680.python-list@python.org> (permalink)

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On 2015.04.29 04:08, Mark Lawrence wrote:
> On 29/04/2015 09:29, Cecil Westerhof wrote:
>> Because I try to keep my lines (well) below 80 characters, I use the
>> following:
>>      print('Calculating fibonacci and fibonacci_memoize once for ' +
>>            str(large_fibonacci) + ' to determine speed increase')
>>
>> But I was told that using + with strings was bad practice. Is this
>> true? If so, what is the better way to do this?
>>
> 
> It's not bad practice as such, it's simply that performance takes a nose 
> dive if you're contatenating large numbers of strings.  If performance 
> is an issue the recommended way is to write.
> 
> ' '.join(strings)
> 
I thought it was frowned upon because it's less readable for anything non-trivial.

hero1 = 'Batman'
hero2 = 'Robin'
villain = 'The Joker'
place = 'Gotham City'

sentence = hero1 + " and " + hero2 + " fight " + villain + " in " + place + "."
# doesn't flow as well as:
sentence = "{hero1} and {hero2} fight {villain} in {place}.".format(
		hero1=hero1,hero2=hero2,villain=villain,place=place)

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Using + with strings considered bad Cecil Westerhof <Cecil@decebal.nl> - 2015-04-29 10:29 +0200
  Re: Using + with strings considered bad Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-04-29 10:08 +0100
  Re: Using + with strings considered bad Peter Otten <__peter__@web.de> - 2015-04-29 11:24 +0200
    Re: Using + with strings considered bad Cecil Westerhof <Cecil@decebal.nl> - 2015-04-29 13:17 +0200
    Re: Using + with strings considered bad Cecil Westerhof <Cecil@decebal.nl> - 2015-04-29 14:23 +0200
      Re: Using + with strings considered bad Chris Angelico <rosuav@gmail.com> - 2015-04-29 22:55 +1000
  Re: Using + with strings considered bad Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-29 23:15 +1000
    Re: Using + with strings considered bad wxjmfauth@gmail.com - 2015-04-29 08:16 -0700
  Re: Using + with strings considered bad Andrew Berg <aberg010@my.hennepintech.edu> - 2015-04-29 06:40 -0500

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