Operators applied to static values and not columns in SQLAlchemy

bindparam.py

# Imagine Model has start_time field and you want to filter all events that 
# fall into an intersection of two DateTimeRanges (tsrange in PostreSQL).

# Doing daterange intersections in Python is tedious, Postgresql is much better at it.
# That requires applying operators to a value (not a column) and that is not so 
# straightforward:

query = DB.session.query(Model)

range1 = DateTimeRange(datetime(2017, 1, 5, 0), datetime(2017, 1, 5, 10, 5))
range2 = DateTimeRange(datetime(2017, 1, 5, 10, 0), datetime(2017, 1, 5, 15, 0))
# intersection is DateTimeRange(datetime(2017, 1, 5, 10, 0), datetime(2017, 1, 5, 10, 5))

query = query.filter(Model.start_time.op('<@')(sqlalchemy.sql.expression.bindparam("r1", range1).op('*')(range2)))
# <@ is 'contained in' operator
# * is an intersection operator

return query.all()