Add python filters is_null, is_not_null, and Filter.not_()

py/server/deephaven/filters.py

@@ -37,6 +37,14 @@ def j_object(self) -> jpy.JType:
  def __init__(self, j_filter):
  self.j_filter = j_filter
 
+ def not_(self):
+ """Creates a new filter that evaluates to the opposite of what this filter evaluates to.
+
+ Returns:
+ a new not Filter
+ """
+ return Filter(j_filter=_JFilterNot.of(self.j_filter))
+
  @classmethod
  def from_(cls, conditions: Union[str, List[str]]) -> Union[Filter, List[Filter]]:
  """Creates filter(s) from the given condition(s).
@@ -68,7 +76,7 @@ def or_(filters: List[Filter]) -> Filter:
  filters (List[filter]): the component filters
 
  Returns:
- a new Filter
+ a new or Filter
  """
  return Filter(j_filter=_JFilterOr.of(*[f.j_filter for f in filters]))
 
@@ -80,21 +88,45 @@ def and_(filters: List[Filter]) -> Filter:
  filters (List[filter]): the component filters
 
  Returns:
- a new Filter
+ a new and Filter
  """
  return Filter(j_filter=_JFilterAnd.of(*[f.j_filter for f in filters]))
 
 
 def not_(filter_: Filter) -> Filter:
- """Creates a new filter that evaluates to true when the given filter evaluates to false.
+ """Creates a new filter that evaluates to the opposite of what filter_ evaluates to.
 
  Args:
  filter_ (Filter): the filter to negate with
 
  Returns:
- a new Filter
+ a new not Filter
+ """
+ return filter_.not_()
+
+
+def is_null(col: str) -> Filter:
+ """Creates a new filter that evaluates to true when the col is null, and evaluates to false when col is not null.
+
+ Args:
+ col (str): the column name
+
+ Returns:
+ a new is-null Filter
+ """
+ return Filter(j_filter=_JFilter.isNull(_JColumnName.of(col)))
+
+
+def is_not_null(col: str) -> Filter:
+ """Creates a new filter that evaluates to true when the col is not null, and evaluates to false when col is null.
+
+ Args:
+ col (str): the column name
+
+ Returns:
+ a new is-not-null Filter
  """
- return Filter(j_filter=_JFilterNot.of(filter_.j_filter))
+ return Filter(j_filter=_JFilter.isNotNull(_JColumnName.of(col)))
 
 
 class PatternMode(Enum):

py/server/tests/test_filters.py

@@ -4,8 +4,9 @@
 
 import unittest
 
-from deephaven import read_csv, DHError
-from deephaven.filters import Filter, PatternMode, and_, or_, not_, pattern
+from deephaven import new_table, read_csv, DHError
+from deephaven.column import string_col
+from deephaven.filters import Filter, PatternMode, and_, is_not_null, is_null, or_, not_, pattern
 from tests.testbase import BaseTestCase
 
 
@@ -51,6 +52,19 @@ def test_filter(self):
  filtered_table_not = self.test_table.where(filter_not)
  self.assertEqual(filtered_table_or.size + filtered_table_not.size, self.test_table.size)
 
+ def test_is_null(self):
+ x = new_table([string_col("X", ["a", "b", "c", None, "e", "f"])])
+ x_is_null = new_table([string_col("X", [None])])
+ x_not_is_null = new_table([string_col("X", ["a", "b", "c", "e", "f"])])
+ self.assert_table_equals(x.where(is_null("X")), x_is_null)
+ self.assert_table_equals(x.where(not_(is_null("X"))), x_not_is_null)
+
+ def test_is_not_null(self):
+ x = new_table([string_col("X", ["a", "b", "c", None, "e", "f"])])
+ x_is_not_null = new_table([string_col("X", ["a", "b", "c", "e", "f"])])
+ x_not_is_not_null = new_table([string_col("X", [None])])
+ self.assert_table_equals(x.where(is_not_null("X")), x_is_not_null)
+ self.assert_table_equals(x.where(not_(is_not_null("X"))), x_not_is_not_null)
 
 if __name__ == '__main__':
  unittest.main()