count

Returns the number of items in a group.

Syntax

from pyspark.sql import functions as sf

sf.count(col)

Parameters

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

Returns

pyspark.sql.Column: column for computed results.

Examples

Example 1: Count all rows in a DataFrame

from pyspark.sql import functions as sf
df = spark.createDataFrame([(None,), ("a",), ("b",), ("c",)], schema=["alphabets"])
df.select(sf.count(sf.expr("*"))).show()

+--------+
|count(1)|
+--------+
|       4|
+--------+

Example 2: Count non-null values in a specific column

from pyspark.sql import functions as sf
df.select(sf.count(df.alphabets)).show()

+----------------+
|count(alphabets)|
+----------------+
|               3|
+----------------+

Example 3: Count all rows in a DataFrame with multiple columns

from pyspark.sql import functions as sf
df = spark.createDataFrame(
    [(1, "apple"), (2, "banana"), (3, None)], schema=["id", "fruit"])
df.select(sf.count(sf.expr("*"))).show()

+--------+
|count(1)|
+--------+
|       3|
+--------+

Example 4: Count non-null values in multiple columns

from pyspark.sql import functions as sf
df.select(sf.count(df.id), sf.count(df.fruit)).show()

+---------+------------+
|count(id)|count(fruit)|
+---------+------------+
|        3|           2|
+---------+------------+