append to non-existing list

Mike Meyer mwm at
Wed Nov 9 21:53:08 CET 2005

"Fredrik Lundh" <fredrik at> writes:

> Mike Meyer wrote:
>> Float doesn't handle implicit conversion to anything but but builtin types.
>> In particular, it doesn't check to see if the object beinng added has a
>> __float__ method, and invoke that to do the conversion if it does.
> that's because __float__ is there to let you control what float() does,
> not to get automatic type conversion for mixed operations.

So is there a mechanism to indicate to the builtin types how they
should coerce some user-defined class into themselves?

Mike Meyer <mwm at>
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.

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