pyspark.sql.functions.
coalesce
Returns the first column that is not null.
New in version 1.4.0.
Examples
>>> cDf = spark.createDataFrame([(None, None), (1, None), (None, 2)], ("a", "b")) >>> cDf.show() +----+----+ | a| b| +----+----+ |null|null| | 1|null| |null| 2| +----+----+
>>> cDf.select(coalesce(cDf["a"], cDf["b"])).show() +--------------+ |coalesce(a, b)| +--------------+ | null| | 1| | 2| +--------------+
>>> cDf.select('*', coalesce(cDf["a"], lit(0.0))).show() +----+----+----------------+ | a| b|coalesce(a, 0.0)| +----+----+----------------+ |null|null| 0.0| | 1|null| 1.0| |null| 2| 0.0| +----+----+----------------+