Wemake-python-styleguide: Forbid to use `lI` names

[sobolevn]

Rule request

Thesis

Currently one can name your classes like so: ControlIn
And it is unreadable! Inside it is just L and i, but we cannot tell it from the word.

We need to forbid lowercase l followed by uppercase I

Reasoning

Readability matters!

[sobolevn]

Are there any other letters that behave like that?

[NickVolynkin]

• digit 1: Fill1List.
• digit 0 and letter o: Memo0Output
• Obviously, same letters in reverse order, Il.

[NickVolynkin]

Also there are letters (Unicode codepoints) which are different but look just the same.
For example, there's Latin A, Greek Α, Cyrillic А.

But actually, let's just ban any letters outside the standard ASCII set. Anything which requires using non-English keyboard layout, anything which has modifiers. And emojis. Emojis are the worst.

[sobolevn]

Thanks!

• I (i uppercase) and l (L lowercase) should be banned too!
• We have already banned all unicode chars in variable names.
• Can you please tell more about 1? It does not look similar to l or L
• What about o and 0 and O?

[NickVolynkin]

l1I and 0O are distinguishable, but still risky. Probably, a warning?

[sobolevn]

We don't have warnings. Errors are better!

[kennycontreras]

Anyone is working on this?

[sobolevn]

No, @kennycontreras feel free to take this one! Ask any questions you have.

[Kvm99]

Hi. Could I take the issue?

[kennycontreras]

@Kvm99 Yes please, I don't have much time at the moment so I'll leave it for now.

[sobolevn]

@kennycontreras no worries, come back when you will have the time! 👍

@Kvm99 thanks a lot! Assigned!