Range types doesn't support infinity [now,infinity)

Python dates don't support infinity, so the value is mapped on maxdate, and of course the mapping is not bidirectional. It's a known shortcoming of the dates mapping, it doesn't affect the ranges only.

You have two solutions:

1. if you don't need the values of the range in python but are using the range only as a key to fetch/store records you may create a text range leaving the ranges unparsed.

2. if your database stores infinity but not maxdate you can create a datetime adapter mapping python maxdate on postgres infinity and build a range on it.

Both objects are easy to implement and use. Let me know if you need a hand with them.

InfDateAdapter.getquoted should return a bytestring in Python 3, but this is not obvious from the documentation, and the stack trace is kind of cryptic. I think people unfamiliar with psycopg2 adapters would benefit from writing the example with b"" literals.

Thank you for the tip, will fix the docs.