Hướng dẫn dùng pyspark orderby python

You can use either sort() or orderBy() function of PySpark DataFrame to sort DataFrame by ascending or descending order based on single or multiple columns, you can also do sorting using PySpark SQL sorting functions, In this article, I will explain all these different ways using PySpark examples.

• Using sort() function
• Using orderBy() function
• Ascending order
• Descending order
• SQL Sort functions

Related: How to sort DataFrame by using Scala

Before we start, first let’s create a DataFrame.

simpleData = [("James","Sales","NY",90000,34,10000), \
    ("Michael","Sales","NY",86000,56,20000), \
    ("Robert","Sales","CA",81000,30,23000), \
    ("Maria","Finance","CA",90000,24,23000), \
    ("Raman","Finance","CA",99000,40,24000), \
    ("Scott","Finance","NY",83000,36,19000), \
    ("Jen","Finance","NY",79000,53,15000), \
    ("Jeff","Marketing","CA",80000,25,18000), \
    ("Kumar","Marketing","NY",91000,50,21000) \
  ]
columns= ["employee_name","department","state","salary","age","bonus"]
df = spark.createDataFrame(data = simpleData, schema = columns)
df.printSchema()
df.show(truncate=False)

This Yields below output.

root
 |-- employee_name: string (nullable = true)
 |-- department: string (nullable = true)
 |-- state: string (nullable = true)
 |-- salary: integer (nullable = false)
 |-- age: integer (nullable = false)
 |-- bonus: integer (nullable = false)

+-------------+----------+-----+------+---+-----+
|employee_name|department|state|salary|age|bonus|
+-------------+----------+-----+------+---+-----+
|        James|     Sales|   NY| 90000| 34|10000|
|      Michael|     Sales|   NY| 86000| 56|20000|
|       Robert|     Sales|   CA| 81000| 30|23000|
|        Maria|   Finance|   CA| 90000| 24|23000|
|        Raman|   Finance|   CA| 99000| 40|24000|
|        Scott|   Finance|   NY| 83000| 36|19000|
|          Jen|   Finance|   NY| 79000| 53|15000|
|         Jeff| Marketing|   CA| 80000| 25|18000|
|        Kumar| Marketing|   NY| 91000| 50|21000|
+-------------+----------+-----+------+---+-----+

DataFrame sorting using the sort() function

PySpark DataFrame class provides sort() function to sort on one or more columns. By default, it sorts by ascending order.

Syntax

sort(self, *cols, **kwargs):

Example

df.sort("department","state").show(truncate=False)
df.sort(col("department"),col("state")).show(truncate=False)

The above two examples return the same below output, the first one takes the DataFrame column name as a string and the next takes columns in Column type. This table sorted by the first department column and then the state column.

+-------------+----------+-----+------+---+-----+
|employee_name|department|state|salary|age|bonus|
+-------------+----------+-----+------+---+-----+
|Maria        |Finance   |CA   |90000 |24 |23000|
|Raman        |Finance   |CA   |99000 |40 |24000|
|Jen          |Finance   |NY   |79000 |53 |15000|
|Scott        |Finance   |NY   |83000 |36 |19000|
|Jeff         |Marketing |CA   |80000 |25 |18000|
|Kumar        |Marketing |NY   |91000 |50 |21000|
|Robert       |Sales     |CA   |81000 |30 |23000|
|James        |Sales     |NY   |90000 |34 |10000|
|Michael      |Sales     |NY   |86000 |56 |20000|
+-------------+----------+-----+------+---+-----+

DataFrame sorting using orderBy() function

PySpark DataFrame also provides orderBy() function to sort on one or more columns. By default, it orders by ascending.

Example

df.orderBy("department","state").show(truncate=False)
df.orderBy(col("department"),col("state")).show(truncate=False)

This returns the same output as the previous section.

Sort by Ascending (ASC)

If you wanted to specify the ascending order/sort explicitly on DataFrame, you can use the asc method of the Column function. for example

df.sort(df.department.asc(),df.state.asc()).show(truncate=False)
df.sort(col("department").asc(),col("state").asc()).show(truncate=False)
df.orderBy(col("department").asc(),col("state").asc()).show(truncate=False)

The above three examples return the same output.

+-------------+----------+-----+------+---+-----+
|employee_name|department|state|salary|age|bonus|
+-------------+----------+-----+------+---+-----+
|Maria        |Finance   |CA   |90000 |24 |23000|
|Raman        |Finance   |CA   |99000 |40 |24000|
|Jen          |Finance   |NY   |79000 |53 |15000|
|Scott        |Finance   |NY   |83000 |36 |19000|
|Jeff         |Marketing |CA   |80000 |25 |18000|
|Kumar        |Marketing |NY   |91000 |50 |21000|
|Robert       |Sales     |CA   |81000 |30 |23000|
|James        |Sales     |NY   |90000 |34 |10000|
|Michael      |Sales     |NY   |86000 |56 |20000|
+-------------+----------+-----+------+---+-----+

Sort by Descending (DESC)

If you wanted to specify the sorting by descending order on DataFrame, you can use the desc method of the Column function. for example. From our example, let’s use desc on the state column.

df.sort(df.department.asc(),df.state.desc()).show(truncate=False)
df.sort(col("department").asc(),col("state").desc()).show(truncate=False)
df.orderBy(col("department").asc(),col("state").desc()).show(truncate=False)

This yields the below output for all three examples.

+-------------+----------+-----+------+---+-----+
|employee_name|department|state|salary|age|bonus|
+-------------+----------+-----+------+---+-----+
|Scott        |Finance   |NY   |83000 |36 |19000|
|Jen          |Finance   |NY   |79000 |53 |15000|
|Raman        |Finance   |CA   |99000 |40 |24000|
|Maria        |Finance   |CA   |90000 |24 |23000|
|Kumar        |Marketing |NY   |91000 |50 |21000|
|Jeff         |Marketing |CA   |80000 |25 |18000|
|James        |Sales     |NY   |90000 |34 |10000|
|Michael      |Sales     |NY   |86000 |56 |20000|
|Robert       |Sales     |CA   |81000 |30 |23000|
+-------------+----------+-----+------+---+-----+

Besides asc() and desc() functions, PySpark also provides asc_nulls_first() and asc_nulls_last() and equivalent descending functions.

Using Raw SQL

Below is an example of how to sort DataFrame using raw SQL syntax.

df.createOrReplaceTempView("EMP")
spark.sql("select employee_name,department,state,salary,age,bonus from EMP ORDER BY department asc").show(truncate=False)

The above two examples return the same output as above.

Dataframe Sorting Complete Example

import pyspark
from pyspark.sql import SparkSession
from pyspark.sql.functions import col, asc,desc

spark = SparkSession.builder.appName('SparkByExamples.com').getOrCreate()

simpleData = [("James","Sales","NY",90000,34,10000), \
    ("Michael","Sales","NY",86000,56,20000), \
    ("Robert","Sales","CA",81000,30,23000), \
    ("Maria","Finance","CA",90000,24,23000), \
    ("Raman","Finance","CA",99000,40,24000), \
    ("Scott","Finance","NY",83000,36,19000), \
    ("Jen","Finance","NY",79000,53,15000), \
    ("Jeff","Marketing","CA",80000,25,18000), \
    ("Kumar","Marketing","NY",91000,50,21000) \
  ]
columns= ["employee_name","department","state","salary","age","bonus"]

df = spark.createDataFrame(data = simpleData, schema = columns)

df.printSchema()
df.show(truncate=False)

df.sort("department","state").show(truncate=False)
df.sort(col("department"),col("state")).show(truncate=False)

df.orderBy("department","state").show(truncate=False)
df.orderBy(col("department"),col("state")).show(truncate=False)

df.sort(df.department.asc(),df.state.asc()).show(truncate=False)
df.sort(col("department").asc(),col("state").asc()).show(truncate=False)
df.orderBy(col("department").asc(),col("state").asc()).show(truncate=False)

df.sort(df.department.asc(),df.state.desc()).show(truncate=False)
df.sort(col("department").asc(),col("state").desc()).show(truncate=False)
df.orderBy(col("department").asc(),col("state").desc()).show(truncate=False)

df.createOrReplaceTempView("EMP")
spark.sql("select employee_name,department,state,salary,age,bonus from EMP ORDER BY department asc").show(truncate=False)

This complete example is also available at PySpark sorting GitHub project for reference.

Conclusion

Here you have learned how to Sort PySpark DataFrame columns using sort(), orderBy() and using SQL sort functions and used this function with PySpark SQL along with Ascending and Descending sorting orders.

Happy Learning !!