pyspark.sql.functions.when

pyspark.sql.functions.when(condition, value)

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

New in version 1.4.0.

Parameters:

conditionColumn

a boolean Column expression.

value :

a literal value, or a Column expression.

>>> df.select(when(df[‘age’] == 2, 3).otherwise(4).alias(“age”)).collect()

[Row(age=3), Row(age=4)]

>>> df.select(when(df.age == 2, df.age + 1).alias(“age”)).collect()

[Row(age=3), Row(age=None)]

pyspark.sql.functions.weekofyear pyspark.sql.functions.window