Error on base64.b64decode() ?!

[Christoph Krammer]

On 12 Okt., 17:09, Jean-Paul Calderone <exar... at divmod.com> wrote:
> If you get an incorrect padding error, try appending a "=" and decoding
> again.  If you get the error again, try appending one more "=".  If it
> still doesn't work, then you might be out of luck.

This seems to work in some cases, but not all. Whats the deal with
this adding of "="? Is there an implementation error in python, or are
other implemenations of base64 more robust then they have to be?

Christoph