PySpark – 按多列对数据框进行排序

在本文中，我们将了解如何按多列对 PySpark 数据框进行排序。

可以通过以下方式完成：

• 使用排序（）
• 使用 orderBy()

创建用于演示的数据框：

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 students  data
data = [["1", "sravan", "vignan"],
        ["2", "ojaswi", "vvit"],
        ["3", "rohith", "vvit"],
        ["4", "sridevi", "vignan"],
        ["1", "sravan", "vignan"],
        ["5", "gnanesh", "iit"]]
  
# specify column names
columns = ['student ID', 'student NAME', 'college']
  
# creating a dataframe from the lists of data
dataframe = spark.createDataFrame(data, columns)
  
print("Actual data in dataframe")
  
# show dataframe
dataframe.show()

输出：

方法一：使用sort()函数

该函数用于对列进行排序。

Syntax: dataframe.sort([‘column1′,’column2′,’column n’],ascending=True)

Where,

• dataframe is the dataframe name created from the nested lists using pyspark
• where columns are the llst of columns
• ascending = True specifies order the dataframe in increasing order, ascending=False specifies order the dataframe in decreasing order

示例 1：通过按升序传递多列（2 列）列表来对数据帧进行排序的Python代码。

蟒蛇3

# show dataframe by sorting the dataframe
# based on two columns in ascending order
dataframe.sort(['college','student ID'],
               ascending = True).show()

输出：

示例 2： Python程序通过按降序传递列列表来对数据框进行排序

蟒蛇3

# show dataframe by sorting the dataframe
# based on two columns in descending order
dataframe.sort(['college','student NAME'],
               ascending = False).show()

输出：

方法二：使用 orderBy()函数。

orderBy()函数对一列或多列进行排序。默认情况下，它按升序排序。

Syntax: orderBy(*cols, ascending=True)

Parameters:

• cols: Columns by which sorting is needed to be performed.
• ascending: Boolean value to say that sorting is to be done in ascending order

示例 1： Python程序通过使用 orderby()函数按降序对基于两列的数据框进行排序来显示数据框

蟒蛇3

# show dataframe by sorting the dataframe
# based on two columns in descending
# order using orderby() function
dataframe.orderBy(['student ID','student NAME'],
                  ascending = False).show()

输出：

示例 2： Python程序通过使用 orderby()函数按升序对基于两列的数据框进行排序来显示数据框

蟒蛇3

# show dataframe by sorting the dataframe
# based on two columns in ascending
# order using orderby() function
dataframe.orderBy(['student ID','student NAME'],
                  ascending = True).show()

输出：