operator bug

[lepture]

_underscore_operators = {
    'gt':           operators.gt,
    'lte':          operators.lt,
    'gte':          operators.ge,
    'le':           operators.le,
    'contains':     operators.contains_op,
    'in':           operators.in_op,
    'exact':        operators.eq,
    'iexact':       operators.ilike_op,
    'startswith':   operators.startswith_op,
    'istartswith':  lambda c, x: c.ilike(x.replace('%', '%%') + '%'),
    'iendswith':    lambda c, x: c.ilike('%' + x.replace('%', '%%')),
    'endswith':     operators.endswith_op,
    'isnull':       lambda c, x: x and c != None or c == None,
    'range':        operators.between_op,
    'year':         lambda c, x: extract('year', c) == x,
    'month':        lambda c, x: extract('month', c) == x,
    'day':          lambda c, x: extract('day', c) == x
}

I think there is a bug on lt and lte

I am using this script at https://github.com/lepture/tornado.ext/blob/master/database.py