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[Python-ideas] More classical for-loop
Mikhail Vmikhailwas at gmail.com
Fri Feb 17 12:31:19 EST 2017
On 17 February 2017 at 17:37, Chris Angelico <rosuav at gmail.com> wrote:> On Sat, Feb 18, 2017 at 3:30 AM, Mikhail V <mikhailwas at gmail.com> wrote:> > On 17 February 2017 at 04:59, Chris Angelico <rosuav at gmail.com> wrote:> >>> >> On Fri, Feb 17, 2017 at 2:13 PM, Mikhail V <mikhailwas at gmail.com>> wrote:> >> > Common use case:> >> >> >> > L = [1,3,5,7]> >> >> >> > for i over len(L):> >> > e = L[i]> >> >> >> > or:> >> >> >> > length = len(L)> >> > for i over length:> >> > e = L[i]> >>> >> Better use case:> >>> >> for i, e in enumerate(L):> >>> >> > This would be more compact, yet less readable, more error prone variant.> > I'd avoid it it all costs and even if I don't need the index further in> loop> > body,> > (which happens rarely in my experience) I write e=L[i] in second line> > to make the code more verbose and keep the flow order.> > So your variant (and those proposed in PEP-212) could serve in list> > comprehensions for example, but for common 'expanded' code I find it> > decline of readability, and creating totally different variants for same> > iteration idea.> > But partially that could be simply matter of habit and love to> contractions.>> If you don't need the index, why not just iterate over the list directly?>> for e in L:>> That's the single most obvious way to step through a collection in> Python. What do you need to count up to the length for?>>I have said I need the index, probably you've misread my last comment.Further more I explained why I think iteration over index should be thepreferred way, it help with readability a lot.All my learning years ended up with rewriting most code to "for i inrange()"and I slap myself when I start to write "for e in L".It is exactly where TOOWTDI applies perfectly and it is integer iterationfor me.Mikhail-------------- next part --------------An HTML attachment was scrubbed...URL: <http://mail.python.org/pipermail/python-ideas/attachments/20170217/1d4ef387/attachment.html>
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