When it comes to writing code, directives and commands are dictated by the programming language (e.g. if ... then ... else), which then is for most programming languages English[1], but when it comes to writing comments the programmer is free to choose which language he uses.

Well, it seems that English unites the programming world and famous Hackers like Eric S. Raymond advise every beginning Hacker to first gain a good command of English [2]. Learning a programming language which employs keywords taken from English or any other language though is totally possible without knowing the language itself.

Now, I've read Raymond's view on learning English [2] and I just re-read the "Style Guide for Python Code" [3]. The latter states:

Python coders from non-English speaking countries: please write
your comments in English, unless you are 120% sure that the code
will never be read by people who don't speak your language.

I have to say I honestly disagree with both. I don't doubt the importance of speaking the same language for communication and I agree that English is most likely the language to choose, but the fact that both want to tell the programmer which language to use is a sign of ignorance towards other speakers: Programming is in no way special to any other area where people individually decide which language is appropriate and have been doing so for ages.

Don't tell us which language we should use, we should now best.

You might argue "what's the point anyway" and "we all know it finally boils down to English", but I believe at this level you should accept that people want to use the language they think is most appropriate, and either way choosing one language means excluding others, no matter which one it finally is.

[1] Python actually has a "translation" to Chinese which translates reserved keywords and built in types and allows Chinese variable names: http://sourceforge.net/projects/chinesepython
[2] http://www.catb.org/~esr/faqs/hacker-howto.html#skills4
[3] http://www.python.org/dev/peps/pep-0008/