array_distinct
Removes duplicate values from the array.
Syntax
Python
from pyspark.sql import functions as sf
sf.array_distinct(col)
Parameters
Parameter | Type | Description |
|---|---|---|
|
| 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
Python
from pyspark.sql import functions as sf
df = spark.createDataFrame([([1, 2, 3, 2],)], ['data'])
df.select(sf.array_distinct(df.data)).show()
Output
+--------------------+
|array_distinct(data)|
+--------------------+
| [1, 2, 3]|
+--------------------+
Example 2: Removing duplicate values from multiple arrays
Python
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()
Output
+--------------------+
|array_distinct(data)|
+--------------------+
| [1, 2, 3]|
| [4, 5]|
+--------------------+
Example 3: Removing duplicate values from an array with all identical values
Python
from pyspark.sql import functions as sf
df = spark.createDataFrame([([1, 1, 1],)], ['data'])
df.select(sf.array_distinct(df.data)).show()
Output
+--------------------+
|array_distinct(data)|
+--------------------+
| [1]|
+--------------------+
Example 4: Removing duplicate values from an array with no duplicate values
Python
from pyspark.sql import functions as sf
df = spark.createDataFrame([([1, 2, 3],)], ['data'])
df.select(sf.array_distinct(df.data)).show()
Output
+--------------------+
|array_distinct(data)|
+--------------------+
| [1, 2, 3]|
+--------------------+
Example 5: Removing duplicate values from an empty array
Python
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()
Output
+--------------------+
|array_distinct(data)|
+--------------------+
| []|
+--------------------+