Wemake-python-styleguide: Forbid a[len(a)-1]
Rule request
Thesis
That's a common mistake of gophers. Golang has no negative index (yet?), but Python has.
Bad:
a[len(a) - 1]
a[len(a) + 1] # IndexError
Good:
a[-1]
a[1]
a[len(a) // 2]
The floor division is ok. Plus len and minus len isn't
Reasoning
a[len(a)-1] is slow, a[len(a)+1] is IndexError.
orsinium
All 9 comments
Awesome!
sobolevn
on 9 Oct 2019
@kxepal do you have any comments on this?
sobolevn
on 9 Oct 2019
Can I take this?
abyss143
on 13 Oct 2019
Let's start with #861
Later you can take as many as you want 馃檪
sobolevn
on 13 Oct 2019
Can I take this one?
lensvol
on 14 Oct 2019
Done! Thanks! 馃憤
sobolevn
on 14 Oct 2019
do you have any comments on this?
LGFM, except this case is quite rare one and mostly relates to migration from some Golang to Python. I can't find any similar issues in real Python code.
kxepal
on 14 Oct 2019
👍1
Hi @lensvol, how's it going? Do you need any help?
sobolevn
on 4 Nov 2019
Hi @sobolevn, everything is on track, got distracted by real-life issues sadly :/ Hope I will close it this week.
lensvol
on 4 Nov 2019
🚀1
👍1
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Most helpful comment
Hi @sobolevn, everything is on track, got distracted by real-life issues sadly :/ Hope I will close it this week.