diff options
Diffstat (limited to 'python/pyspark/sql/dataframe.py')
-rw-r--r-- | python/pyspark/sql/dataframe.py | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/python/pyspark/sql/dataframe.py b/python/pyspark/sql/dataframe.py index 078acfdf7e..82cb1c2fdb 100644 --- a/python/pyspark/sql/dataframe.py +++ b/python/pyspark/sql/dataframe.py @@ -1546,6 +1546,37 @@ class Column(object): """ return (self >= lowerBound) & (self <= upperBound) + @ignore_unicode_prefix + def when(self, condition, value): + """Evaluates a list of conditions and returns one of multiple possible result expressions. + If :func:`Column.otherwise` is not invoked, None is returned for unmatched conditions. + + See :func:`pyspark.sql.functions.when` for example usage. + + :param condition: a boolean :class:`Column` expression. + :param value: a literal value, or a :class:`Column` expression. + + """ + sc = SparkContext._active_spark_context + if not isinstance(condition, Column): + raise TypeError("condition should be a Column") + v = value._jc if isinstance(value, Column) else value + jc = sc._jvm.functions.when(condition._jc, v) + return Column(jc) + + @ignore_unicode_prefix + def otherwise(self, value): + """Evaluates a list of conditions and returns one of multiple possible result expressions. + If :func:`Column.otherwise` is not invoked, None is returned for unmatched conditions. + + See :func:`pyspark.sql.functions.when` for example usage. + + :param value: a literal value, or a :class:`Column` expression. + """ + v = value._jc if isinstance(value, Column) else value + jc = self._jc.otherwise(value) + return Column(jc) + def __repr__(self): return 'Column<%s>' % self._jc.toString().encode('utf8') |