cardinality

Collection function: Returns the length of the array or map stored in the column.

For the corresponding Databricks SQL function, see cardinality function.

Syntax

from pyspark.sql import functions as dbf

dbf.cardinality(col=<col>)

Parameters

Parameter	Type	Description
col	pyspark.sql.Column or str	Target column to compute on.

Returns

pyspark.sql.Column: length of the array/map.

Examples

from pyspark.sql import functions as dbf
df = spark.createDataFrame([([1, 2, 3],),([1],),([],)], ['data'])
df.select(dbf.cardinality("data")).show()

+-----------------+
|cardinality(data)|
+-----------------+
|                3|
|                1|
|                0|
+-----------------+