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pyspark日期处理及比较

作者:高景洋　日期:2021-01-28 11:38:26　浏览次数:1590

业务需求：

1、通过pyspark将hbase中的数据拉出

2、通过pyspark按UpdatedDate 、EnteredDate、DeletedDate ，根据WebsiteID字段汇总数量

小白方法：

1、spark拉出hbase数据

2、rdd1 = hbase_result_rdd.map('对日期字段进行处理')

df1 = rdd_to_df(rdd1) # 将rdd转换为dataframe

df2 = df1.filter(df1['UpdatedDate']>datetime.datetime.today().date) # 理想中的样子

现实中的样子：各种日期类型转换问题报错，如：数据中的字段值为None \ 2021-01-22 18:47:48 \ 2021-01-22T18:47:48

大白方法：

1、因此，我们转换思路，查一下，spark有没有内置的日期处理函数。因为之前已经用过内置的随机函数rand()，内置的md5函数md5()，内置的添加列函数lit()

2、果然，pyspark存在内置的日期处理函数：

to_timestamp ：将列转换为日期

current_date : 获取当前日期

3、最后，come on ~ ,来看下最终代码~

	from pyspark.sql.functions import rand,md5,lit,to_timestamp,current_date

		print('更新时间')
	
		df_update_date = list_filter_websiteids.filter(list_filter_websiteids['UpdatedDate']!='--').select('WebsiteID',to_timestamp(list_filter_websiteids['UpdatedDate']).alias('UpdatedDate'))
	
		df_update_date.show()
	
		df_update_date_1 = df_update_date.filter(df_update_date['UpdatedDate']>current_date()).groupby('WebsiteID').count()
	
		df_update_date_1.show()

执行结果：

28-01-2021 11:05:54 CST hbase_scan INFO - 更新时间
28-01-2021 11:05:54 CST hbase_scan INFO - +---------+-------------------+
28-01-2021 11:05:54 CST hbase_scan INFO - |WebsiteID|        UpdatedDate|
28-01-2021 11:05:54 CST hbase_scan INFO - +---------+-------------------+
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-28 08:26:46|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-28 08:59:03|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-28 08:45:54|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - |        1|2021-01-22 18:47:48|
28-01-2021 11:05:54 CST hbase_scan INFO - +---------+-------------------+
28-01-2021 11:05:54 CST hbase_scan INFO - only showing top 20 rows
28-01-2021 11:05:54 CST hbase_scan INFO - 
28-01-2021 11:05:55 CST hbase_scan INFO - 
28-01-2021 11:05:58 CST hbase_scan INFO - [Stage 24:=============================>                            (1 + 1) / 2]
28-01-2021 11:05:58 CST hbase_scan INFO -                                                                                 
28-01-2021 11:05:59 CST hbase_scan INFO - +---------+-----+
28-01-2021 11:05:59 CST hbase_scan INFO - |WebsiteID|count|
28-01-2021 11:05:59 CST hbase_scan INFO - +---------+-----+
28-01-2021 11:05:59 CST hbase_scan INFO - |      108|    1|
28-01-2021 11:05:59 CST hbase_scan INFO - |      521|   55|
28-01-2021 11:05:59 CST hbase_scan INFO - |       71|  762|
28-01-2021 11:05:59 CST hbase_scan INFO - |       23|   29|
28-01-2021 11:05:59 CST hbase_scan INFO - |       70|   16|
28-01-2021 11:05:59 CST hbase_scan INFO - |      167|   17|
28-01-2021 11:05:59 CST hbase_scan INFO - |        1| 1220|
28-01-2021 11:05:59 CST hbase_scan INFO - |      235|  138|
28-01-2021 11:05:59 CST hbase_scan INFO - |      292|   28|
28-01-2021 11:05:59 CST hbase_scan INFO - |      171|    3|
28-01-2021 11:05:59 CST hbase_scan INFO - |       58|  263|
28-01-2021 11:05:59 CST hbase_scan INFO - |      243|    1|
28-01-2021 11:05:59 CST hbase_scan INFO - |      168|   16|
28-01-2021 11:05:59 CST hbase_scan INFO - |       24|  549|
28-01-2021 11:05:59 CST hbase_scan INFO - |       83|  540|
28-01-2021 11:05:59 CST hbase_scan INFO - |      492|    5|
28-01-2021 11:05:59 CST hbase_scan INFO - |      251|    1|
28-01-2021 11:05:59 CST hbase_scan INFO - |      279|    4|
28-01-2021 11:05:59 CST hbase_scan INFO - |       91|  565|
28-01-2021 11:05:59 CST hbase_scan INFO - |       94|  244|
28-01-2021 11:05:59 CST hbase_scan INFO - +---------+-----+
28-01-2021 11:05:59 CST hbase_scan INFO - only showing top 20 rows

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