Python PySpark获取列的最大和最小非零值
我有一个数据框,如下所示:Python PySpark获取列的最大和最小非零值,python,dataframe,apache-spark,pyspark,Python,Dataframe,Apache Spark,Pyspark,我有一个数据框,如下所示: +-------+--------------------+--------------------+--------------+---------+----------+ | label| app_id| title|download_count|entity_id|risk_score| +-------+--------------------+--------------------+---------
+-------+--------------------+--------------------+--------------+---------+----------+
| label| app_id| title|download_count|entity_id|risk_score|
+-------+--------------------+--------------------+--------------+---------+----------+
|ANDROID|com.aaron.test.ze...| Aaron Test| 0| 124| 100|
|ANDROID|com.boulderdailyc...|Boulder Daily Cam...| 100| 122| 100|
|ANDROID|com.communitybank...| Budgeting Tools| 0| 123| 100|
|ANDROID|com.communitybank...| PB Mobile Banking| 600| 123| 100|
|ANDROID|com.mendocinobeac...|Mendocino Beacon ...| 10| 122| 100|
|ANDROID|com.profitstars.t...|Johnson City Mobi...| 500| 123| 100|
|ANDROID|com.spreedinc.pro...|Oneida Dispatch f...| 1000| 122| 100|
+-------+--------------------+--------------------+--------------+---------+----------+
我希望获得按实体ID分组的非零max和mindownload\u count
值。我不太确定如何使用聚合来实现这一点,当然简单的max和min不会起作用
apps_by_entity = (
group_by_entity_id(df)
.agg(F.min(df.download_count), F.max(df.download_count), F.count("entity_id").alias("app_count"))
.withColumnRenamed("max(download_count)", "download_max")
.withColumnRenamed("min(download_count)", "download_min")
)
因为实体123和124的最小值为0
+---------+------------+------------+---------+
|entity_id|download_min|download_max|app_count|
+---------+------------+------------+---------+
| 124| 0| 0| 1|
| 123| 0| 600| 3|
| 122| 10| 1000| 3|
+---------+------------+------------+---------+
所需的输出类似于
+---------+------------+------------+---------+
|entity_id|download_min|download_max|app_count|
+---------+------------+------------+---------+
| 124| 0| 0| 1|
| 123| 500| 600| 3|
| 122| 10| 1000| 3|
+---------+------------+------------+---------+
有没有一种方法可以通过聚合实现这一点?如果不是,那么获得非零值的最佳方法是什么?在
max=min=0
的情况下,只返回0
或null
就可以了。我不确定在进行最小、最大聚合时是否可以排除零,而不会丢失计数实现输出的一种方法是分别对聚合进行(最小、最大)和计数,然后将它们重新连接起来
from pyspark.sql.functions import *
from pyspark.sql import functions as F
min_max_df = df.filter(col("download_count")!=0).groupBy('entity_id')\
.agg(F.min('download_count').alias("download_min"),\
F.max('download_count').alias("download_max"))\
.withColumnRenamed("entity_id", "entity_id_1")
count_df =df.groupBy('entity_id').agg(F.count('download_count')\
.alias("app_count"))
count_df.join(min_max_df, (count_df.entity_id == min_max_df.entity_id_1), \
"left").drop("entity_id_1").fillna(0, subset=['download_min',\
'download_max']).show()
+---------+---------+------------+------------+
|entity_id|app_count|download_min|download_max|
+---------+---------+------------+------------+
| 124| 1| 0| 0|
| 123| 3| 500| 600|
| 122| 3| 10| 1000|
+---------+---------+------------+------------+
啊哈,我正要回答我自己的问题,但这正是我最后要做的,谢谢你写下这篇文章