Unexpected Python Behavior

[David Bolen]

Greg Ewing <greg at cosc.canterbury.ac.nz> writes:

> Alex Martelli wrote:
> > I think it's in fact very nice syntax:
> > def f(x, cache=[]):
> >     if x in cache: ...
> 
> No, it's not, because it suggests that cache is
> intended to be an optional parameter, whereas it
> probably isn't.

Depends - I'd probably read that just as you say - it's an optional
parameter.  But why assume it probably isn't intended that way.  If I
want to use my own cache I pass it in, otherwise I expect the function
to have a default cache that it will use for me.

-- David