pyspark.sql.Column.when¶

Column.when(condition: pyspark.sql.column.Column, value: Any) → pyspark.sql.column.Column[source]¶

Evaluates a list of conditions and returns one of multiple possible result expressions. If Column.otherwise() is not invoked, None is returned for unmatched conditions.

New in version 1.4.0.

Changed in version 3.4.0: Supports Spark Connect.

Parameters

conditionColumn: a boolean Column expression.
value: a literal value, or a Column expression.

Returns

Column: Column representing whether each element of Column is in conditions.

See also

pyspark.sql.functions.when

Examples

>>> from pyspark.sql import functions as F
>>> df = spark.createDataFrame(
...      [(2, "Alice"), (5, "Bob")], ["age", "name"])
>>> df.select(df.name, F.when(df.age > 4, 1).when(df.age < 3, -1).otherwise(0)).show()
+-----+------------------------------------------------------------+
| name|CASE WHEN (age > 4) THEN 1 WHEN (age < 3) THEN -1 ELSE 0 END|
+-----+------------------------------------------------------------+
|Alice|                                                          -1|
|  Bob|                                                           1|
+-----+------------------------------------------------------------+

pyspark.sql.Column.substr pyspark.sql.Column.withField