count
Returns the number of items in a group.
Syntax
Python
from pyspark.sql import functions as sf
sf.count(col)
Parameters
Parameter | Type | Description |
|---|---|---|
|
| Target column to compute on. |
Returns
pyspark.sql.Column: column for computed results.
Examples
Example 1: Count all rows in a DataFrame
Python
from pyspark.sql import functions as sf
df = spark.createDataFrame([(None,), ("a",), ("b",), ("c",)], schema=["alphabets"])
df.select(sf.count(sf.expr("*"))).show()
Output
+--------+
|count(1)|
+--------+
| 4|
+--------+
Example 2: Count non-null values in a specific column
Python
from pyspark.sql import functions as sf
df.select(sf.count(df.alphabets)).show()
Output
+----------------+
|count(alphabets)|
+----------------+
| 3|
+----------------+
Example 3: Count all rows in a DataFrame with multiple columns
Python
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()
Output
+--------+
|count(1)|
+--------+
| 3|
+--------+
Example 4: Count non-null values in multiple columns
Python
from pyspark.sql import functions as sf
df.select(sf.count(df.id), sf.count(df.fruit)).show()
Output
+---------+------------+
|count(id)|count(fruit)|
+---------+------------+
| 3| 2|
+---------+------------+