import keyword behaviour - performance impact if used multiple times?

[Diez B. Roggisch]

> If I run fileB, will this import the psycopg twice, or once only? Is
> this something to do with system modules being singletons?

It will be imported only once. Of course the statement will be read twice -
but as this only happens while reading the *.py the first time, you needn't
bother about performance issues.
-- 
Regards,

Diez B. Roggisch