使用显式模式创建一个带有模式的PySpark DataFrame: df=spark.createDataFrame([(1,2.,'string1',date(2000,1,1),datetime(2000,1,1,12,0)),(2,3.,'string2',date(2000,2,1),datetime(2000,1,2,12,0)),(3,4.,'string3',date(2000,3,1),datetime(2000,1,3,12,0))],schema='a long, ...
val parquetFilters = new ParquetFilters(parquetSchema, pushDownDate, pushDownTimestamp, pushDownDecimal, pushDownStringStartWith, pushDownInFilterThreshold, isCaseSensitive) filters // Collects all converted Parquet filter predicates. Notice that not all predicates can be // converted (`ParquetFilters.crea...
pythonPath)// This is equivalent to setting the -u flag; we use it because ipython doesn't support -u:env.put("PYTHONUNBUFFERED","YES")// value is needed to be set to a non-empty stringenv.put("PYSPARK_GATEWAY_PORT
cache()同步数据的内存 columns 返回一个string类型的数组,返回值是所有列的名字 dtypes返回一个string类型的二维数组,返回值是所有列的名字以及类型 explan()打印执行计划 物理的 explain(n:Boolean) 输入值为 false 或者true ,返回值是unit 默认是false ,如果输入true 将会打印 逻辑的和物理的 isLocal 返回值是Bo...
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#展示数字或string列的统计信息,可以指定列,默认是所有列,包括count, mean, stddev, min, and max df.describe(['age', 'weight', 'height']).show() #展示数字或string列的统计信息,处理describe的信息,还包括25%,50%,75% df.select("age", "weight", "height").summary().show() ...
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[Row(ages=u'2'), Row(ages=u'5')]>>>df.select(df.age.cast(StringType()).alias('ages')).collect() [Row(ages=u'2'), Row(ages=u'5')] 5.9 desc() 基于给定列名称的降序返回一个排序表达式。 5.10 endswith(other) 二元运算符 ...
dataframe只有3列: stringStartTimeStanp - 'HH:MM:SS:MI'*EndTimeStanp -数据类型,例如“时间戳”或可以在表单‘HH:MM:SS:MI’*EndTimeStanp中持有时间戳(无日期部分)的数据类型--类似于“时间戳”之类的数据类型或可以在表单'HH:MM:SS:MI'*中持有时间戳(无日期部分)的数据类型。 *小时:分钟...
env.put("PYTHONUNBUFFERED", "YES") // value is needed to be set to a non-empty string env.put("PYSPARK_GATEWAY_PORT", "" + gatewayServer.getListeningPort) // pass conf spark.pyspark.python to python process, the only way to pass info to ...