PostreSQL SQL for MySQL SQL

Hi,

I'm fairly new to PostreSQL, coming from MySQL. My Python application
generates these MySQL commands:

drop database if exists Foo;
create database Foo;
use Foo;

Using the PostgreSQL online docs, my closest translation is:

drop database Foo;
create database Foo;

What I'm missing is:
* "if exists" for the drop, in order to avoid an error the very first time
this program runs
* the "use Foo;"

Can I do these things in PostreSQL from SQL (e.g., not from the command line)?

-Chuck