array_distinct

Removes duplicate values from the array.

Syntax

from pyspark.sql import functions as sf

sf.array_distinct(col)

Parameters

Parameter	Type	Description
col	pyspark.sql.Column or str	Name of column or expression

Returns

pyspark.sql.Column: A new column that is an array of unique values from the input column.

Examples

Example 1: Removing duplicate values from a simple array

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

+--------------------+
|array_distinct(data)|
+--------------------+
|           [1, 2, 3]|
+--------------------+

Example 2: Removing duplicate values from multiple arrays

from pyspark.sql import functions as sf
df = spark.createDataFrame([([1, 2, 3, 2],), ([4, 5, 5, 4],)], ['data'])
df.select(sf.array_distinct(df.data)).show()

+--------------------+
|array_distinct(data)|
+--------------------+
|           [1, 2, 3]|
|              [4, 5]|
+--------------------+

Example 3: Removing duplicate values from an array with all identical values

from pyspark.sql import functions as sf
df = spark.createDataFrame([([1, 1, 1],)], ['data'])
df.select(sf.array_distinct(df.data)).show()

+--------------------+
|array_distinct(data)|
+--------------------+
|                 [1]|
+--------------------+

Example 4: Removing duplicate values from an array with no duplicate values

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

+--------------------+
|array_distinct(data)|
+--------------------+
|           [1, 2, 3]|
+--------------------+

Example 5: Removing duplicate values from an empty array

from pyspark.sql import functions as sf
from pyspark.sql.types import ArrayType, IntegerType, StructType, StructField
schema = StructType([
  StructField("data", ArrayType(IntegerType()), True)
])
df = spark.createDataFrame([([],)], schema)
df.select(sf.array_distinct(df.data)).show()

+--------------------+
|array_distinct(data)|
+--------------------+
|                  []|
+--------------------+