How to test if a module exists?

[Lawrence D'Oliveiro]

I have just received an admission from Barry Warsaw that a hack was done on 
python-list specifically to deal with bounces caused by a list member trying 
to reply to my obfuscated e-mail address.

I have asked him to undo that hack. If he likes, he can filter out that 
(obfuscated) address of mine completely, I don’t mind, since I can always 
read replies to my postings here on USENET. The important point, as far as 
I’m concerned, is that I do NOT want to see my unobfuscated address appear 
on USENET.

As for those who persisted in posting my address after being warned of this, 
I’m still deciding what to do.