1.去重方法 dropDuplicates功能:对DF的数据进行去重,如果重复数据有多条,取第一条 2.删除有缺失值的行方法 dropna功能:如果数据中包含null,通过dropna来进行判断,符合条件就删除这一行数据 3.填充缺失值数据 fillna功能:根据参数的规则,来进行null的替换 7.DataFrame数据写出 spark.read.format()和df.write.format(...
6.SparkSQL 数据清洗API 1.去重方法 dropDuplicates 功能:对DF的数据进行去重,如果重复数据有多条,取第一条 2.删除有缺失值的行方法 dropna 功能:如果数据中包含null,通过dropna来进行判断,符合条件就删除这一行数据 3.填充缺失值数据 fillna 功能:根据参数的规则,来进行null的替换 7.DataFrame数据写出 spark.read...
grouped_and_ranked = df.withColumn(rank_name, F.row_number().over(window)) result = grouped_and_ranked.dropDuplicates(subset=[part_key, rank_name]) if topn != '': result = result.filter(F.col(rank_name) <= topn) return result user_topn(df, key, col, 1) 1. 2. 3. 4. 5. ...
select() ; show() ; filter() ; group() ; count() ; orderby() ; dropDuplicates() ; withColumnRenamed() ; printSchema() ; columns ; describe() # SQL 查询 ## 由于sql无法直接对DataFrame进行查询,需要先建立一张临时表df.createOrReplaceTempView("table") query='select x1,x2 from table w...
pyspark.sql.functions module provides string functions to work with strings for manipulation and data processing. String functions can be applied to
n = np.array(df) print(n) DataFrame增加一列数据 import pandas as pd import numpy as np data = pd.DataFrame...删除重复的数据行 import pandas as pd norepeat_df = df.drop_duplicates(subset=['A_ID', 'B_ID'], keep='first...读写操作 将csv文件读入DataFrame数据 read_csv()函数的参数配...
PySpark distinct() transformation is used to drop/remove the duplicate rows (all columns) from DataFrame and dropDuplicates() is used to drop rows based
dropDuplicates(['name', 'height']) # Replace empty strings with null (leave out subset keyword arg to replace in all columns) df = df.replace({"": None}, subset=["name"]) # Convert Python/PySpark/NumPy NaN operator to null df = df.replace(float("nan"), None) String Operations ...
dropDuplicates() Powered By Queries >>> from pyspark.sql import functions as F Powered By Select >>> df.select("firstName").show() #Show all entries in firstName column>>> df.select("firstName","lastName") \ .show()>>> df.select("firstName", #Show all entries in firstName...
Then this utility will help you in quickly generating Spark JDBC connection string for Importing & Exporting data. Read More PySpark Cheat Sheet Starting with PySpark ? Check this PySpark Cheat Sheet to help you get started quickly. Read More ...