[Python-Dev] Very Strange Argument Handling Behavior (original) (raw)

Raymond Hettinger raymond.hettinger at gmail.com
Fri Apr 16 23:11:30 CEST 2010

Guido van Rossum, 16.04.2010 16:33:

I am fine with declaring dict({}, **{1:3}) illegal, since after all it is abuse of the ** mechanism.

ISTM that making it illegal costs cycles with giving any real benefit. It is reasonably common to accept **kwds and then pass it down to another function. Do we want to validate the keys of every kwds dict on every call? Why do we even care?

If I'm understanding the proposal correctly, it means that every existing application using **kwds will pay a price, either by breaking (because it uses non-string keys) or by running slower (so that every call can be checked to make sure it didn't use string keys).

Raymond

More information about the Python-Dev mailing list