[Python-Dev] PEP 343 and context() (original) (raw)

Jason Orendorff jason.orendorff at gmail.com
Fri Jan 20 21:34:52 CET 2006

On 1/20/06, Nick Coghlan <ncoghlan at gmail.com> wrote:

Jason Orendorff wrote: > DecimalContext has a few problems. In code where it matters, every > function you write has to worry about it. (That is, you can't just > write decimalcontext = ... at the top of the file and be done > with it, the way you can with, say, metaclass.)

No, you write "decimal.setcontext(...)" instead.

You seem to be implying these are roughly equal in convenience; I disagree. Suppose I have banking.py, in which it's important to use a particular precision and rounding. Now I have to put context-munging code in every single function that banking.py exposes. And around every 'yield'. Even with 'with', that's a lot of extra lines of code.

I'd much prefer to put a one-liner at the top of the file, if it were possible (...but I don't see how, yet).

Again, none of this is likely to matter--unless you're interleaving banking and heavy scientific calculations, which I try to avoid. So, not a big deal. Thanks for the response.

> And > DecimalContext doesn't fit in with generators.

It does fit actually - you simply have to remember to restore the original context around any invocations of yield.

Feh! "Fit" is to "can be made to work with a bit of effort, just don't forget to follow the rules" as Python is to C++.

-j

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