Add "or" filters to python. (#1650)

* Add an or filter

* Update filter.py

* Fixed unit test and code after running.

* Addressed code review.

Co-authored-by: Jianfeng Mao <4297243+jmao-denver@users.noreply.github.com>

Integrations/python/deephaven/__init__.py

@@ -90,7 +90,8 @@
  ParquetTools as pt, \
  TableTools as ttools, \
  TableLoggers as tloggers, \
- Types as dh
+ Types as dh, \
+ filter as _filter
 
 from .Plot import figure_wrapper as figw
 
@@ -119,6 +120,7 @@ def initialize():
  ttools._defineSymbols()
  tloggers._defineSymbols()
  csv._defineSymbols()
+ _filter._defineSymbols()
 
  import deephaven.TableManipulation
  deephaven.TableManipulation._defineSymbols()

Integrations/python/deephaven/filter.py

@@ -0,0 +1,59 @@
+#
+# Copyright (c) 2016-2021 Deephaven Data Labs and Patent Pending
+#
+""" The deephaven.filter module provides methods for filtering Deephaven tables."""
+
+import jpy
+import wrapt
+
+_JFilter = None
+_JFilterOr = None
+
+
+def _defineSymbols():
+ """
+ Defines appropriate java symbol, which requires that the jvm has been initialized through the :class:`jpy` module,
+ for use throughout the module AT RUNTIME. This is versus static definition upon first import, which would lead to an
+ exception if the jvm wasn't initialized BEFORE importing the module.
+ """
+
+ if not jpy.has_jvm():
+ raise SystemError("No java functionality can be used until the JVM has been initialized through the jpy module")
+
+ global _JFilter, _JFilterOr
+
+ if _JFilter is None:
+ # This will raise an exception if the desired object is not the classpath
+ _JFilter = jpy.get_type("io.deephaven.api.filter.Filter")
+ _JFilterOr = jpy.get_type("io.deephaven.api.filter.FilterOr")
+
+
+# every module method should be decorated with @_passThrough
+@wrapt.decorator
+def _passThrough(wrapped, instance, args, kwargs):
+ """
+ For decoration of module methods, to define necessary symbols at runtime
+
+ :param wrapped: the method to be decorated
+ :param instance: the object to which the wrapped function was bound when it was called
+ :param args: the argument list for `wrapped`
+ :param kwargs: the keyword argument dictionary for `wrapped`
+ :return: the decorated version of the method
+ """
+
+ _defineSymbols()
+ return wrapped(*args, **kwargs)
+
+
+@_passThrough
+def or_(*filters) -> object:
+ """ Filters on cases where any of the input filters evaluate to true.
+
+ Args:
+ *filters (str): the filter expressions
+
+ Returns:
+ a filter that evaluates to true when any of the input filters evaluates to true
+ """
+
+ return _JFilterOr.of(_JFilter.from_(filters))

Integrations/python/test/test_filter.py

@@ -0,0 +1,30 @@
+#
+# Copyright (c) 2016-2021 Deephaven Data Labs and Patent Pending
+#
+import unittest
+
+from deephaven.TableTools import newTable, intCol, diff
+from deephaven.filter import or_
+from unittest import TestCase
+
+
+class FilterTestCase(TestCase):
+ def test_or(self):
+ t = newTable(
+ intCol("A", 1, 2, 3, 4, 5),
+ intCol("B", 11, 12, 13, 14, 15)
+ )
+
+ t_target = newTable(
+ intCol("A", 1, 4, 5),
+ intCol("B", 11, 14, 15)
+ )
+
+ t_actual = t.where(or_("A<2", "B>=14"))
+
+ diff_string = diff(t_actual, t_target, 1)
+ self.assertEqual("", diff_string)
+
+
+if __name__ == '__main__':
+ unittest.main()