Drop duplicate rows in PySpark DataFrame

In this article, we are going to drop the duplicate rows by using distinct() and dropDuplicates() functions from dataframe using pyspark in Python. 

Let’s create a sample Dataframe

Python3

# importing module
import pyspark

# importing sparksession from
# pyspark.sql module
from pyspark.sql import SparkSession

# creating sparksession and giving
# an app name
spark = SparkSession.builder.appName('sparkdf').getOrCreate()

# list  of employee data
data = [["1", "sravan", "company 1"],
        ["2", "ojaswi", "company 1"],
        ["3", "rohith", "company 2"],
        ["4", "sridevi", "company 1"],
        ["1", "sravan", "company 1"],
        ["4", "sridevi", "company 1"]]

# specify column names
columns = ['Employee ID', 'Employee NAME', 'Company']

# creating a dataframe from the
# lists of data
dataframe = spark.createDataFrame(data, columns)

print('Actual data in dataframe')
dataframe.show()

Output:

Method 1: Distinct

Distinct data means unique data. It will remove the duplicate rows in the dataframe

Syntax: dataframe.distinct()

where, dataframe is the dataframe name created from the nested lists using pyspark

Python3

print('distinct data after dropping duplicate rows')

# display distinct data
dataframe.distinct().show()

Output:

We can use the select() function along with distinct function to get distinct values from particular columns

Syntax: dataframe.select([‘column 1′,’column n’]).distinct().show()

Python3

# display distinct data in Employee
# ID and Employee NAME
dataframe.select(['Employee ID', 'Employee NAME']).distinct().show()

Output:

Method 2: dropDuplicate

Syntax: dataframe.dropDuplicates()

where, dataframe is the dataframe name created from the nested lists using pyspark

Python3

# remove duplicate data using
# dropDuplicates()function
dataframe.dropDuplicates().show()

Output:

Python program to remove duplicate values in specific columns

Python3

# remove duplicate data using
# dropDuplicates() function in
# two columns
dataframe.select(['Employee ID', 'Employee NAME']
                ).dropDuplicates().show()

Output: