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Posted to user@pig.apache.org by Björn-Elmar Macek <ma...@cs.uni-kassel.de> on 2012/10/01 16:42:08 UTC
Jython UDFs, Tuples and Stringconversions
Hi,
i am currently writing a PIG script that works with a bags of timestamp
tuples. So i am basically working on a datastructure like this:
(tuple(chararray)), int, bag{tuple(chararray)})
for example:
( ('a','b','c','d'), 3, {('2012-03-04 10:10:10'), ('2012-03-04 10:10:11')} )
When loading the data i add a schema, so pig knows what data is coming in:
x = load 'tag_count_ts_pro_userpair' as (group:tuple(),cnt:int,times:bag{});
I then want to change the content of the times-bag, by replacing every
timestamp with an integer, based on the time distance to a certain date,
which i do with the follwing UDFs:
###### myUDF.py ##############
from org.apache.pig.scripting import *
import datetime
import math
@outputSchema("days_from_start:bag{t:tuple(cnt:int)}")
def daysFromStart(startDate, aBagOfDates):
if aBagOfDates is None: return None;
result=[]
for somedate in aBagOfDates:
if somedate is None: continue
aDateString = ''.join(somedate)
#ALTERNATIVELY I USED ALSO: aDateString =
''.join(somedate[0]) // aDateString = ''.join(somedate[1])
if len(aDateString==16): result.append(diffTime(startDate,
aDateString))
return result
@outputSchema("diff:int")
def diffTime(dateFrom,dateTil):
dateSmall = datetime.datetime.strptime(dateFrom,"%Y-%m-%d %H:%M:%S");
dateBig = datetime.datetime.strptime(dateTil,"%Y-%m-%d %H:%M:%S");
delta = dateBig-dateSmall
return delta.days
##########################
I do this by executing the following command in the grunt:
y = foreach x generate *, moins.daysFromStart('2011-06-01 00:00:00', times);
But when i try to store y, i get the following error message:
######## LOG #############
2012-10-01 16:35:03,499 [main] ERROR
org.apache.pig.tools.pigstats.SimplePigStats - ERROR 2997: Unable to
recreate exception from backed error:
org.apache.pig.backend.executionengine.ExecException: ERROR 0: Error
executing function
at
org.apache.pig.scripting.jython.JythonFunction.exec(JythonFunction.java:106)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:216)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:258)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.getNext(PhysicalOperator.java:316)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.processPlan(POForEach.java:332)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNext(POForEach.java:284)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.runPipeline(PigGenericMapBase.java:271)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:266)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:64)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
at org.apache.hadoop.mapred.Child.main(Child.java:249)
Caused by: Traceback (most recent call last):
File "/gpfs/home02/fb16/bmacek/myUDF.py", line 38, in daysFromStart
aDateString = ''.join(somedate[0])
TypeError: sequence item 0: expected string, int found
at org.python.core.Py.TypeError(Py.java:235)
at org.python.core.PyString.str_join(PyString.java:1900)
at org.python.core.PyString$str_join_exposer.__call__(Unknown Source)
at org.python.core.PyObject.__call__(PyObject.java:391)
at
org.python.pycode._pyx3.daysFromStart$3(/gpfs/home02/fb16/bmacek/myUDF.py:40)
at
org.python.pycode._pyx3.call_function(/gpfs/home02/fb16/bmacek/myUDF.py)
at org.python.core.PyTableCode.call(PyTableCode.java:165)
at org.python.core.PyBaseCode.call(PyBaseCode.java:301)
at org.python.core.PyFunction.function___call__(PyFunction.java:376)
at org.python.core.PyFunction.__call__(PyFunction.java:371)
at org.python.core.PyFunction.__call__(PyFunction.java:361)
at org.python.core.PyFunction.__call__(PyFunction.java:356)
at
org.apache.pig.scripting.jython.JythonFunction.exec(JythonFunction.java:103)
... 16 more
##############################
Depending on the line...
---
aDateString = ''.join(somedate)
#ALTERNATIVELY I USED ALSO: aDateString =
''.join(somedate[0]) // aDateString = ''.join(somedate[1])
---
... i get different error messages: when i use index 0, the error msg
above is given, if i use 1 it is outofbounds, and if i omit the
squarebrackets, the error message says:
2012-10-01 16:40:46,280 [main] ERROR
org.apache.pig.tools.pigstats.SimplePigStats - ERROR 2997: Unable to
recreate exception from backed error:
org.apache.pig.backend.executionengine.ExecException: ERROR 0: Error
executing function
at
org.apache.pig.scripting.jython.JythonFunction.exec(JythonFunction.java:106)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:216)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:258)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.getNext(PhysicalOperator.java:316)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.processPlan(POForEach.java:332)
at
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNext(POForEach.java:284)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.runPipeline(PigGenericMapBase.java:271)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:266)
at
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:64)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
at org.apache.hadoop.mapred.Child.main(Child.java:249)
Caused by: Traceback (most recent call last):
File "/gpfs/home02/fb16/bmacek/myUDF.py", line 38, in daysFromStart
aDateString = ''.join(somedate)
TypeError: sequence item 0: expected string, array.array found
at org.python.core.Py.TypeError(Py.java:235)
at org.python.core.PyString.str_join(PyString.java:1900)
at org.python.core.PyString$str_join_exposer.__call__(Unknown Source)
at org.python.core.PyObject.__call__(PyObject.java:391)
at
org.python.pycode._pyx3.daysFromStart$3(/gpfs/home02/fb16/bmacek/myUDF.py:40)
at
org.python.pycode._pyx3.call_function(/gpfs/home02/fb16/bmacek/myUDF.py)
at org.python.core.PyTableCode.call(PyTableCode.java:165)
at org.python.core.PyBaseCode.call(PyBaseCode.java:301)
at org.python.core.PyFunction.function___call__(PyFunction.java:376)
at org.python.core.PyFunction.__call__(PyFunction.java:371)
at org.python.core.PyFunction.__call__(PyFunction.java:361)
at org.python.core.PyFunction.__call__(PyFunction.java:356)
at
org.apache.pig.scripting.jython.JythonFunction.exec(JythonFunction.java:103)
... 16 more
Can anybody please tell me, what i am doing wrong here?
Thanks for your time and help in advance!
Björn
Re: Jython UDFs, Tuples and Stringconversions
Posted by Björn-Elmar Macek <ma...@cs.uni-kassel.de>.
Hi Cheilsoo,
ahh thank you for the modifications: the output is what i expect it to
be. I will have to look up the Arrayconstruct [1:-1] tho. I could solve
the issue by adding a complete schema just as you did with
times:{(chararray)}
.
Thank you alot for your time and insight!
Björn
Am 01.10.2012 23:11, schrieb Cheolsoo Park:
> Hi,
>
> Please try this:
>
> 1. I used a tab-separated input file as follows:
>
> cheolsoo@localhost:~/workspace/pig-svn $cat tag_count_ts_pro_userpair
> ('a','b','c','d') 3 {('2012-03-04 10:10:10'),('2013-03-04 10:10:11')}
>
> 2. My udf is as follows:
>
> import datetime
>
> @outputSchema("days_from_start:bag{t:tuple(cnt:int)}")
> def daysFromStart(startDate, aBagOfDates):
> if aBagOfDates is None: return None
> result=[]
> for someDate in aBagOfDates:
> if someDate is None: continue
> someDate = ''.join(someDate)
> if len(someDate)==21: result.append(diffTime(startDate,
> someDate))
> return result
>
> @outputSchema("diff:int")
> def diffTime(dateFrom, dateTil):
> dateSmall = datetime.datetime.strptime(dateFrom, "%Y-%m-%d %H:%M:%S")
> dateBig = datetime.datetime.strptime(dateTil[1:-1], "%Y-%m-%d %H:%M:%S")
> delta = dateBig - dateSmall
> return delta.days
>
> 3. My pig script is as follows:
>
> register 'udf.py' using jython as moins;
>
> x = load 'tag_count_ts_pro_userpair' using PigStorage('\t') as (group:(),
> cnt:int, times:{(chararray)});
> y = foreach x generate *, moins.daysFromStart('2011-06-01 00:00:00', times);
> dump y;
>
> This returns:
>
> (('a','b','c','d'),3,{('2012-03-04 10:10:10'),('2013-03-04
> 10:10:11')},{(277),(642)})
>
> Thanks,
> Cheolsoo
>
> On Mon, Oct 1, 2012 at 7:42 AM, Björn-Elmar Macek <ma...@cs.uni-kassel.de>wrote:
>
>> Hi,
>>
>> i am currently writing a PIG script that works with a bags of timestamp
>> tuples. So i am basically working on a datastructure like this:
>> (tuple(chararray)), int, bag{tuple(chararray)})
>>
>> for example:
>> ( ('a','b','c','d'), 3, {('2012-03-04 10:10:10'), ('2012-03-04 10:10:11')}
>> )
>>
>> When loading the data i add a schema, so pig knows what data is coming in:
>> x = load 'tag_count_ts_pro_userpair' as (group:tuple(),cnt:int,times:**
>> bag{});
>>
>> I then want to change the content of the times-bag, by replacing every
>> timestamp with an integer, based on the time distance to a certain date,
>> which i do with the follwing UDFs:
>> ###### myUDF.py ##############
>> from org.apache.pig.scripting import *
>> import datetime
>> import math
>>
>>
>> @outputSchema("days_from_**start:bag{t:tuple(cnt:int)}")
>> def daysFromStart(startDate, aBagOfDates):
>> if aBagOfDates is None: return None;
>> result=[]
>> for somedate in aBagOfDates:
>> if somedate is None: continue
>> aDateString = ''.join(somedate)
>> #ALTERNATIVELY I USED ALSO: aDateString = ''.join(somedate[0])
>> // aDateString = ''.join(somedate[1])
>> if len(aDateString==16): result.append(diffTime(**startDate,
>> aDateString))
>> return result
>>
>>
>> @outputSchema("diff:int")
>> def diffTime(dateFrom,dateTil):
>> dateSmall = datetime.datetime.strptime(**dateFrom,"%Y-%m-%d
>> %H:%M:%S");
>> dateBig = datetime.datetime.strptime(**dateTil,"%Y-%m-%d %H:%M:%S");
>> delta = dateBig-dateSmall
>> return delta.days
>>
>> ##########################
>>
>> I do this by executing the following command in the grunt:
>> y = foreach x generate *, moins.daysFromStart('2011-06-**01 00:00:00',
>> times);
>>
>> But when i try to store y, i get the following error message:
>>
>> ######## LOG #############
>> 2012-10-01 16:35:03,499 [main] ERROR org.apache.pig.tools.pigstats.**SimplePigStats
>> - ERROR 2997: Unable to recreate exception from backed error:
>> org.apache.pig.backend.**executionengine.ExecException: ERROR 0: Error
>> executing function
>> at org.apache.pig.scripting.**jython.JythonFunction.exec(**
>> JythonFunction.java:106)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> expressionOperators.**POUserFunc.getNext(POUserFunc.**java:216)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> expressionOperators.**POUserFunc.getNext(POUserFunc.**java:258)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> PhysicalOperator.getNext(**PhysicalOperator.java:316)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> relationalOperators.POForEach.**processPlan(POForEach.java:**332)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> relationalOperators.POForEach.**getNext(POForEach.java:284)
>> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
>> PigGenericMapBase.runPipeline(**PigGenericMapBase.java:271)
>> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
>> PigGenericMapBase.map(**PigGenericMapBase.java:266)
>> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
>> PigGenericMapBase.map(**PigGenericMapBase.java:64)
>> at org.apache.hadoop.mapreduce.**Mapper.run(Mapper.java:144)
>> at org.apache.hadoop.mapred.**MapTask.runNewMapper(MapTask.**java:764)
>> at org.apache.hadoop.mapred.**MapTask.run(MapTask.java:370)
>> at org.apache.hadoop.mapred.**Child$4.run(Child.java:255)
>> at java.security.**AccessController.doPrivileged(**Native Method)
>> at javax.security.auth.Subject.**doAs(Subject.java:415)
>> at org.apache.hadoop.security.**UserGroupInformation.doAs(**
>> UserGroupInformation.java:**1121)
>> at org.apache.hadoop.mapred.**Child.main(Child.java:249)
>> Caused by: Traceback (most recent call last):
>> File "/gpfs/home02/fb16/bmacek/**myUDF.py", line 38, in daysFromStart
>> aDateString = ''.join(somedate[0])
>> TypeError: sequence item 0: expected string, int found
>>
>> at org.python.core.Py.TypeError(**Py.java:235)
>> at org.python.core.PyString.str_**join(PyString.java:1900)
>> at org.python.core.PyString$str_**join_exposer.__call__(Unknown
>> Source)
>> at org.python.core.PyObject.__**call__(PyObject.java:391)
>> at org.python.pycode._pyx3.**daysFromStart$3(/gpfs/home02/**
>> fb16/bmacek/myUDF.py:40)
>> at org.python.pycode._pyx3.call_**function(/gpfs/home02/fb16/**
>> bmacek/myUDF.py)
>> at org.python.core.PyTableCode.**call(PyTableCode.java:165)
>> at org.python.core.PyBaseCode.**call(PyBaseCode.java:301)
>> at org.python.core.PyFunction.**function___call__(PyFunction.**
>> java:376)
>> at org.python.core.PyFunction.__**call__(PyFunction.java:371)
>> at org.python.core.PyFunction.__**call__(PyFunction.java:361)
>> at org.python.core.PyFunction.__**call__(PyFunction.java:356)
>> at org.apache.pig.scripting.**jython.JythonFunction.exec(**
>> JythonFunction.java:103)
>> ... 16 more
>> ##############################
>>
>> Depending on the line...
>> ---
>> aDateString = ''.join(somedate)
>> #ALTERNATIVELY I USED ALSO: aDateString = ''.join(somedate[0])
>> // aDateString = ''.join(somedate[1])
>> ---
>> ... i get different error messages: when i use index 0, the error msg
>> above is given, if i use 1 it is outofbounds, and if i omit the
>> squarebrackets, the error message says:
>>
>> 2012-10-01 16:40:46,280 [main] ERROR org.apache.pig.tools.pigstats.**SimplePigStats
>> - ERROR 2997: Unable to recreate exception from backed error:
>> org.apache.pig.backend.**executionengine.ExecException: ERROR 0: Error
>> executing function
>> at org.apache.pig.scripting.**jython.JythonFunction.exec(**
>> JythonFunction.java:106)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> expressionOperators.**POUserFunc.getNext(POUserFunc.**java:216)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> expressionOperators.**POUserFunc.getNext(POUserFunc.**java:258)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> PhysicalOperator.getNext(**PhysicalOperator.java:316)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> relationalOperators.POForEach.**processPlan(POForEach.java:**332)
>> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
>> relationalOperators.POForEach.**getNext(POForEach.java:284)
>> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
>> PigGenericMapBase.runPipeline(**PigGenericMapBase.java:271)
>> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
>> PigGenericMapBase.map(**PigGenericMapBase.java:266)
>> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
>> PigGenericMapBase.map(**PigGenericMapBase.java:64)
>> at org.apache.hadoop.mapreduce.**Mapper.run(Mapper.java:144)
>> at org.apache.hadoop.mapred.**MapTask.runNewMapper(MapTask.**java:764)
>> at org.apache.hadoop.mapred.**MapTask.run(MapTask.java:370)
>> at org.apache.hadoop.mapred.**Child$4.run(Child.java:255)
>> at java.security.**AccessController.doPrivileged(**Native Method)
>> at javax.security.auth.Subject.**doAs(Subject.java:415)
>> at org.apache.hadoop.security.**UserGroupInformation.doAs(**
>> UserGroupInformation.java:**1121)
>> at org.apache.hadoop.mapred.**Child.main(Child.java:249)
>> Caused by: Traceback (most recent call last):
>> File "/gpfs/home02/fb16/bmacek/**myUDF.py", line 38, in daysFromStart
>> aDateString = ''.join(somedate)
>> TypeError: sequence item 0: expected string, array.array found
>>
>> at org.python.core.Py.TypeError(**Py.java:235)
>> at org.python.core.PyString.str_**join(PyString.java:1900)
>> at org.python.core.PyString$str_**join_exposer.__call__(Unknown
>> Source)
>> at org.python.core.PyObject.__**call__(PyObject.java:391)
>> at org.python.pycode._pyx3.**daysFromStart$3(/gpfs/home02/**
>> fb16/bmacek/myUDF.py:40)
>> at org.python.pycode._pyx3.call_**function(/gpfs/home02/fb16/**
>> bmacek/myUDF.py)
>> at org.python.core.PyTableCode.**call(PyTableCode.java:165)
>> at org.python.core.PyBaseCode.**call(PyBaseCode.java:301)
>> at org.python.core.PyFunction.**function___call__(PyFunction.**
>> java:376)
>> at org.python.core.PyFunction.__**call__(PyFunction.java:371)
>> at org.python.core.PyFunction.__**call__(PyFunction.java:361)
>> at org.python.core.PyFunction.__**call__(PyFunction.java:356)
>> at org.apache.pig.scripting.**jython.JythonFunction.exec(**
>> JythonFunction.java:103)
>> ... 16 more
>>
>>
>>
>> Can anybody please tell me, what i am doing wrong here?
>>
>> Thanks for your time and help in advance!
>> Björn
>>
>>
>>
Re: Jython UDFs, Tuples and Stringconversions
Posted by Cheolsoo Park <ch...@cloudera.com>.
Hi,
Please try this:
1. I used a tab-separated input file as follows:
cheolsoo@localhost:~/workspace/pig-svn $cat tag_count_ts_pro_userpair
('a','b','c','d') 3 {('2012-03-04 10:10:10'),('2013-03-04 10:10:11')}
2. My udf is as follows:
import datetime
@outputSchema("days_from_start:bag{t:tuple(cnt:int)}")
def daysFromStart(startDate, aBagOfDates):
if aBagOfDates is None: return None
result=[]
for someDate in aBagOfDates:
if someDate is None: continue
someDate = ''.join(someDate)
if len(someDate)==21: result.append(diffTime(startDate,
someDate))
return result
@outputSchema("diff:int")
def diffTime(dateFrom, dateTil):
dateSmall = datetime.datetime.strptime(dateFrom, "%Y-%m-%d %H:%M:%S")
dateBig = datetime.datetime.strptime(dateTil[1:-1], "%Y-%m-%d %H:%M:%S")
delta = dateBig - dateSmall
return delta.days
3. My pig script is as follows:
register 'udf.py' using jython as moins;
x = load 'tag_count_ts_pro_userpair' using PigStorage('\t') as (group:(),
cnt:int, times:{(chararray)});
y = foreach x generate *, moins.daysFromStart('2011-06-01 00:00:00', times);
dump y;
This returns:
(('a','b','c','d'),3,{('2012-03-04 10:10:10'),('2013-03-04
10:10:11')},{(277),(642)})
Thanks,
Cheolsoo
On Mon, Oct 1, 2012 at 7:42 AM, Björn-Elmar Macek <ma...@cs.uni-kassel.de>wrote:
> Hi,
>
> i am currently writing a PIG script that works with a bags of timestamp
> tuples. So i am basically working on a datastructure like this:
> (tuple(chararray)), int, bag{tuple(chararray)})
>
> for example:
> ( ('a','b','c','d'), 3, {('2012-03-04 10:10:10'), ('2012-03-04 10:10:11')}
> )
>
> When loading the data i add a schema, so pig knows what data is coming in:
> x = load 'tag_count_ts_pro_userpair' as (group:tuple(),cnt:int,times:**
> bag{});
>
> I then want to change the content of the times-bag, by replacing every
> timestamp with an integer, based on the time distance to a certain date,
> which i do with the follwing UDFs:
> ###### myUDF.py ##############
> from org.apache.pig.scripting import *
> import datetime
> import math
>
>
> @outputSchema("days_from_**start:bag{t:tuple(cnt:int)}")
> def daysFromStart(startDate, aBagOfDates):
> if aBagOfDates is None: return None;
> result=[]
> for somedate in aBagOfDates:
> if somedate is None: continue
> aDateString = ''.join(somedate)
> #ALTERNATIVELY I USED ALSO: aDateString = ''.join(somedate[0])
> // aDateString = ''.join(somedate[1])
> if len(aDateString==16): result.append(diffTime(**startDate,
> aDateString))
> return result
>
>
> @outputSchema("diff:int")
> def diffTime(dateFrom,dateTil):
> dateSmall = datetime.datetime.strptime(**dateFrom,"%Y-%m-%d
> %H:%M:%S");
> dateBig = datetime.datetime.strptime(**dateTil,"%Y-%m-%d %H:%M:%S");
> delta = dateBig-dateSmall
> return delta.days
>
> ##########################
>
> I do this by executing the following command in the grunt:
> y = foreach x generate *, moins.daysFromStart('2011-06-**01 00:00:00',
> times);
>
> But when i try to store y, i get the following error message:
>
> ######## LOG #############
> 2012-10-01 16:35:03,499 [main] ERROR org.apache.pig.tools.pigstats.**SimplePigStats
> - ERROR 2997: Unable to recreate exception from backed error:
> org.apache.pig.backend.**executionengine.ExecException: ERROR 0: Error
> executing function
> at org.apache.pig.scripting.**jython.JythonFunction.exec(**
> JythonFunction.java:106)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> expressionOperators.**POUserFunc.getNext(POUserFunc.**java:216)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> expressionOperators.**POUserFunc.getNext(POUserFunc.**java:258)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> PhysicalOperator.getNext(**PhysicalOperator.java:316)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> relationalOperators.POForEach.**processPlan(POForEach.java:**332)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> relationalOperators.POForEach.**getNext(POForEach.java:284)
> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
> PigGenericMapBase.runPipeline(**PigGenericMapBase.java:271)
> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
> PigGenericMapBase.map(**PigGenericMapBase.java:266)
> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
> PigGenericMapBase.map(**PigGenericMapBase.java:64)
> at org.apache.hadoop.mapreduce.**Mapper.run(Mapper.java:144)
> at org.apache.hadoop.mapred.**MapTask.runNewMapper(MapTask.**java:764)
> at org.apache.hadoop.mapred.**MapTask.run(MapTask.java:370)
> at org.apache.hadoop.mapred.**Child$4.run(Child.java:255)
> at java.security.**AccessController.doPrivileged(**Native Method)
> at javax.security.auth.Subject.**doAs(Subject.java:415)
> at org.apache.hadoop.security.**UserGroupInformation.doAs(**
> UserGroupInformation.java:**1121)
> at org.apache.hadoop.mapred.**Child.main(Child.java:249)
> Caused by: Traceback (most recent call last):
> File "/gpfs/home02/fb16/bmacek/**myUDF.py", line 38, in daysFromStart
> aDateString = ''.join(somedate[0])
> TypeError: sequence item 0: expected string, int found
>
> at org.python.core.Py.TypeError(**Py.java:235)
> at org.python.core.PyString.str_**join(PyString.java:1900)
> at org.python.core.PyString$str_**join_exposer.__call__(Unknown
> Source)
> at org.python.core.PyObject.__**call__(PyObject.java:391)
> at org.python.pycode._pyx3.**daysFromStart$3(/gpfs/home02/**
> fb16/bmacek/myUDF.py:40)
> at org.python.pycode._pyx3.call_**function(/gpfs/home02/fb16/**
> bmacek/myUDF.py)
> at org.python.core.PyTableCode.**call(PyTableCode.java:165)
> at org.python.core.PyBaseCode.**call(PyBaseCode.java:301)
> at org.python.core.PyFunction.**function___call__(PyFunction.**
> java:376)
> at org.python.core.PyFunction.__**call__(PyFunction.java:371)
> at org.python.core.PyFunction.__**call__(PyFunction.java:361)
> at org.python.core.PyFunction.__**call__(PyFunction.java:356)
> at org.apache.pig.scripting.**jython.JythonFunction.exec(**
> JythonFunction.java:103)
> ... 16 more
> ##############################
>
> Depending on the line...
> ---
> aDateString = ''.join(somedate)
> #ALTERNATIVELY I USED ALSO: aDateString = ''.join(somedate[0])
> // aDateString = ''.join(somedate[1])
> ---
> ... i get different error messages: when i use index 0, the error msg
> above is given, if i use 1 it is outofbounds, and if i omit the
> squarebrackets, the error message says:
>
> 2012-10-01 16:40:46,280 [main] ERROR org.apache.pig.tools.pigstats.**SimplePigStats
> - ERROR 2997: Unable to recreate exception from backed error:
> org.apache.pig.backend.**executionengine.ExecException: ERROR 0: Error
> executing function
> at org.apache.pig.scripting.**jython.JythonFunction.exec(**
> JythonFunction.java:106)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> expressionOperators.**POUserFunc.getNext(POUserFunc.**java:216)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> expressionOperators.**POUserFunc.getNext(POUserFunc.**java:258)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> PhysicalOperator.getNext(**PhysicalOperator.java:316)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> relationalOperators.POForEach.**processPlan(POForEach.java:**332)
> at org.apache.pig.backend.hadoop.**executionengine.physicalLayer.**
> relationalOperators.POForEach.**getNext(POForEach.java:284)
> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
> PigGenericMapBase.runPipeline(**PigGenericMapBase.java:271)
> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
> PigGenericMapBase.map(**PigGenericMapBase.java:266)
> at org.apache.pig.backend.hadoop.**executionengine.**mapReduceLayer.**
> PigGenericMapBase.map(**PigGenericMapBase.java:64)
> at org.apache.hadoop.mapreduce.**Mapper.run(Mapper.java:144)
> at org.apache.hadoop.mapred.**MapTask.runNewMapper(MapTask.**java:764)
> at org.apache.hadoop.mapred.**MapTask.run(MapTask.java:370)
> at org.apache.hadoop.mapred.**Child$4.run(Child.java:255)
> at java.security.**AccessController.doPrivileged(**Native Method)
> at javax.security.auth.Subject.**doAs(Subject.java:415)
> at org.apache.hadoop.security.**UserGroupInformation.doAs(**
> UserGroupInformation.java:**1121)
> at org.apache.hadoop.mapred.**Child.main(Child.java:249)
> Caused by: Traceback (most recent call last):
> File "/gpfs/home02/fb16/bmacek/**myUDF.py", line 38, in daysFromStart
> aDateString = ''.join(somedate)
> TypeError: sequence item 0: expected string, array.array found
>
> at org.python.core.Py.TypeError(**Py.java:235)
> at org.python.core.PyString.str_**join(PyString.java:1900)
> at org.python.core.PyString$str_**join_exposer.__call__(Unknown
> Source)
> at org.python.core.PyObject.__**call__(PyObject.java:391)
> at org.python.pycode._pyx3.**daysFromStart$3(/gpfs/home02/**
> fb16/bmacek/myUDF.py:40)
> at org.python.pycode._pyx3.call_**function(/gpfs/home02/fb16/**
> bmacek/myUDF.py)
> at org.python.core.PyTableCode.**call(PyTableCode.java:165)
> at org.python.core.PyBaseCode.**call(PyBaseCode.java:301)
> at org.python.core.PyFunction.**function___call__(PyFunction.**
> java:376)
> at org.python.core.PyFunction.__**call__(PyFunction.java:371)
> at org.python.core.PyFunction.__**call__(PyFunction.java:361)
> at org.python.core.PyFunction.__**call__(PyFunction.java:356)
> at org.apache.pig.scripting.**jython.JythonFunction.exec(**
> JythonFunction.java:103)
> ... 16 more
>
>
>
> Can anybody please tell me, what i am doing wrong here?
>
> Thanks for your time and help in advance!
> Björn
>
>
>