I've created: https://issues.apache.org/jira/browse/ARROW-10197 I put priority "Trivial" -- not sure if it is correct.
On Tue, Oct 6, 2020 at 3:41 PM Wes McKinney <[email protected]> wrote: > This looks like something to improve in the Python bindings. Would you > like to open a JIRA issue about it? > > On Tue, Oct 6, 2020 at 4:26 AM Kirill Lykov <[email protected]> > wrote: > > > > Hi, > > > > I'm trying to write a code in python which executes an expression on > > filtered data. So I create a filter and later projector for some > expression > > but don't get how to combine those two in python: > > > > ```python > > import pyarrow as pa > > import pyarrow.gandiva as gandiva > > > > table = pa.Table.from_arrays([pa.array([1., 31., 46., 3., 57., 44., > 22.]), > > pa.array([5., 45., 36., 73., > > 83., 23., 76.])], > > ['a', 'b']) > > > > builder = gandiva.TreeExprBuilder() > > node_a = builder.make_field(table.schema.field("a")) > > node_b = builder.make_field(table.schema.field("b")) > > fifty = builder.make_literal(50.0, pa.float64()) > > eleven = builder.make_literal(11.0, pa.float64()) > > > > cond_1 = builder.make_function("less_than", [node_a, fifty], pa.bool_()) > > cond_2 = builder.make_function("greater_than", [node_a, node_b], > > pa.bool_()) > > cond_3 = builder.make_function("less_than", [node_b, eleven], pa.bool_()) > > cond = builder.make_or([builder.make_and([cond_1, cond_2]), cond_3]) > > condition = builder.make_condition(cond) > > > > filter = gandiva.make_filter(table.schema, condition) > > # filterResult has type SelectionVector > > filterResult = filter.evaluate(table.to_batches()[0], > > pa.default_memory_pool()) > > print(result) > > > > sum = builder.make_function("add", [node_a, node_b], pa.float64()) > > field_result = pa.field("c", pa.float64()) > > expr = builder.make_expression(sum, field_result) > > projector = gandiva.make_projector( > > table.schema, [expr], pa.default_memory_pool()) > > > > ### Here there is a problem that I don't know how to use filterResult > with > > projector > > r, = projector.evaluate(table.to_batches()[0], result) > > ``` > > > > In C++, I see that it is possible to pass SelectionVector as second > > argument to projector::Evaluate: > > > https://github.com/apache/arrow/blob/c5fa23ea0e15abe47b35524fa6a79c7b8c160fa0/cpp/src/gandiva/tests/filter_project_test.cc#L270 > > > > Meanwhile, it looks like it is impossible in `gandiva.pyx`: > > > https://github.com/apache/arrow/blob/a4eb08d54ee0d4c0d0202fa0a2dfa8af7aad7a05/python/pyarrow/gandiva.pyx#L154 > > > > > > > > -- > > Best regards, > > Kirill Lykov > -- Best regards, Kirill Lykov
