def __init__(self, *, _op=EXPR, _children=None, _negated=False, _expr=None, **kwargs):
"""
Create a new R object.
Query filters can be expressed through keyword arguments or using methods.
Ex.
.. code-block:: python
rql = R(field='value', field2__in=('v1', 'v2'), field3__empty=True)
All the lookups expressed as keyword arguments are combined together with a logical ``and``.
Using the ``n`` method:
.. code-block:: python
rql = (
R().n('field').eq('value')
& R().n('field2').in_(('v1', 'v2'))
& R().n('field3').empty(True)
)
The previous query can be expressed in a more concise form like:
.. code-block:: python
rql = R().field.eq('value') & R().field2.in_(('v1', 'v2')) & r.field3.empty(True)
The R object support the bitwise operators ``&``, ``|`` and ``~``.
Nested fields can be expressed using dot notation:
.. code-block:: python
rql = R().n('nested.field').eq('value')
or
.. code-block:: python
rql = R().nested.field.eq('value')
"""
self.op = _op
self.children = _children or []
self.negated = _negated
self.expr = _expr
self._path = []
self._field = None
if len(kwargs) == 1:
self.op = self.EXPR
self.expr = parse_kwargs(kwargs)[0]
if len(kwargs) > 1:
self.op = self.AND
for token in parse_kwargs(kwargs):
self.children.append(RQLQuery(_expr=token))
def test_simple():
expressions = parse_kwargs({'field': 'value'})
assert isinstance(expressions, list)
assert len(expressions) == 1
assert expressions[0] == 'eq(field,value)'
def test_null(expr, value, expected_op):
expressions = parse_kwargs({f'field__{expr}': value})
assert isinstance(expressions, list)
assert len(expressions) == 1
assert expressions[0] == f'{expected_op}(field,{expr}())'
def test_nested_fields():
expressions = parse_kwargs({'field__nested': 'value'})
assert isinstance(expressions, list)
assert len(expressions) == 1
assert expressions[0] == 'eq(field.nested,value)'
def test_list():
for op in ('out', 'in'):
expressions = parse_kwargs({f'field__{op}': ('value1', 'value2')})
assert isinstance(expressions, list)
assert len(expressions) == 1
assert expressions[0] == f'{op}(field,(value1,value2))'
def test_comparison():
for op in ('eq', 'ne', 'lt', 'le', 'gt', 'ge'):
expressions = parse_kwargs({f'field__{op}': 'value'})
assert isinstance(expressions, list)
assert len(expressions) == 1
assert expressions[0] == f'{op}(field,value)'