dvarrazzo/psycopg — comment on commit d2b67364fd2b0b192342281d24a7e3d0a4909980
File: lib/__init__.py line 145
By fknittel:

The difference is a slight change of behaviour. Previously, the port parameter would have been ignored for the "port == 0" case, now it's only ignored for the "port is None" case. So instead of using the default port if port is specified as 0, an error is generated.

But this is probably an obscure corner case of the existing interface which hopefully noone relies on.