我有一个时间戳数据集,其格式为:
我在Pyspark中编写了一个UDF来处理此数据集并将其作为键值对映射返回。但是我收到以下错误消息:
数据集:df_ts_list
+--------------------+
| ts_list|
+--------------------+
|[1477411200, 1477...|
|[1477238400, 1477...|
|[1477022400, 1477...|
|[1477224000, 1477...|
|[1477256400, 1477...|
|[1477346400, 1476...|
|[1476986400, 1477...|
|[1477321200, 1477...|
|[1477306800, 1477...|
|[1477062000, 1477...|
|[1477249200, 1477...|
|[1477040400, 1477...|
|[1477090800, 1477...|
+--------------------+
Pyspark用户自定义函数:
>>> def on_time(ts_list):
... import sys
... import os
... sys.path.append('/usr/lib/python2.7/dist-packages')
... os.system("sudo apt-get install python-numpy -y")
... import numpy as np
... import datetime
... import time
... from datetime import timedelta
... ts = np.array(ts_list)
... if ts.size == 0:
... count = 0
... duration = 0
... st = time.mktime(datetime.now())
... ymd = str(datetime.fromtimestamp(st).date())
... else:
... ts.sort()
... one_tag = []
... start = float(ts[0])
... for i in range(len(ts)):
... if i == (len(ts)) - 1:
... end = float(ts[i])
... a_round = [start, end]
... one_tag.append(a_round)
... else:
... diff = (datetime.datetime.fromtimestamp(float(ts[i+1])) - datetime.datetime.fromtimestamp(float(ts[i])))
... if abs(diff.total_seconds()) > 3600:
... end = float(ts[i])
... a_round = [start, end]
... one_tag.append(a_round)
... start = float(ts[i+1])
... one_tag = [u for u in one_tag if u[1] - u[0] > 300]
... count = int(len(one_tag))
... duration = int(np.diff(one_tag).sum())
... ymd = str(datetime.datetime.fromtimestamp(time.time()).date())
... return {'count':count,'duration':duration, 'ymd':ymd}
Pyspark 代码:
>>> on_time=udf(on_time, MapType(StringType(),StringType()))
>>> df_ts_list.withColumn("one_tag", on_time("ts_list")).select("one_tag").show()
Caused by: org.apache.spark.api.python.PythonException: Traceback (most recent call last):
File "/usr/lib/spark/python/pyspark/worker.py", line 172, in main
process()
File "/usr/lib/spark/python/pyspark/worker.py", line 167, in process
serializer.dump_stream(func(split_index, iterator), outfile)
File "/usr/lib/spark/python/pyspark/worker.py", line 106, in <lambda>
func = lambda _, it: map(mapper, it)
File "/usr/lib/spark/python/pyspark/worker.py", line 92, in <lambda>
mapper = lambda a: udf(*a)
File "/usr/lib/spark/python/pyspark/worker.py", line 70, in <lambda>
return lambda *a: f(*a)
File "<stdin>", line 27, in on_time
File "/usr/lib/spark/python/pyspark/sql/functions.py", line 39, in _
jc = getattr(sc._jvm.functions, name)(col._jc if isinstance(col, Column) else col)
AttributeError: 'NoneType' object has no attribute '_jvm'
任何帮助都将不胜感激!
def func(is_test = lit(False))
。 - JacksonHaenchendef is_not_empty(): return (col('var') != lit(''))
。然后将其作为函数而不是变量使用。这样可以在调用时(在初始化Spark上下文之后)实例化它,而不是在加载模块时。 - Brendan