[ubertaco]

There are levels of "knowing" a language.

I've been writing Java since I was 14 (for 11 years now). I write Java on a daily basis for work, and I can't remember the last time I had to consult a reference on syntax. I would consider that "fluent", to use an analog from spoken/written languages, and I'd obviously put any languages in which I'm "fluent" on my resume.

I've written a lot of Python in my personal time over the years, and have a good understanding of what "idiomatic" Python looks like (comprehensions over iterators/higher-order-functions, "is"/"in" over "=="/"indexOf", etc). I would consider this "conversational", and would put it on my resume too.

Then there are languages that I have not written any projects in, aside from tutorial-type-things while learning them. These are more on a case-by-case basis; ones that I'm more comfortable with (like Elixir or Haskell) I might put on my resume with a note that I'm at a "beginner" level of familiarity; I understand many of the language concepts, but would need to consult reference material frequently, and my code is not likely to be idiomatic. With these languages, I'd ask myself the question of how comfortable would I be accepting a job where I did nothing but write code in that language. And obviously, I'd need to explain in an interview or phone screen that my knowledge is still basic.

[aerovistae]

Whoa, hold on, since when is 'is' preferred over '=='? What kind of python are you writing over there? Those are for totally different purposes. One tests equality while the other tests identity.

[clintonc]

For example, 'if x == None' versus 'if x is None'. The latter is to be preferred (since identity is faster and more clear than comparison), but you see the former sometimes.

[aerovistae]

Yes that's the only case I know of where 'is' is regularly used.