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Pig >> mail # user >> python udf doesnt work

Xiaomeng Wan 2011-01-24, 23:54
Daniel Dai 2011-01-25, 00:28
Xiaomeng Wan 2011-01-25, 20:50
Richard Ding 2011-01-26, 01:46
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Re: python udf doesnt work
As a workaround, in Jython you can also use the java classes.
Something like: (not tested)

from java.util.regex import *
from java.lang import *

 def strsplittobag(content,regex):
        return Pattern.compile(regex).split(content)


On 1/25/11 5:46 PM, "Richard Ding" <[EMAIL PROTECTED]> wrote:

You're right. There're two issues here. First, the Jython script needs to locate the modules in its search path (e.g. python.path). If you have the right env variable set, Jython script should be able to find and import the module. Second, Pig currently doesn't automatically ship the module file to the backend, so even if you set the search path in the frontend, the backend still cannot locate the module.

Finally, there is incompatibility between Python modules and Jython modules. You need to use Jython modules that come with Jython installation (in the Lib directory).

We're looking into these issues and hoping to provide a solution in the next release.

On 1/25/11 12:50 PM, "Xiaomeng Wan" <[EMAIL PROTECTED]> wrote:

Hi Daniel,

I did put jython.jar in classpath. By comparing other python udfs with
this one, I find those udfs which work do not import anything. Could
that be the cause? Do I need to anything extra to import module in my



On Mon, Jan 24, 2011 at 5:28 PM, Daniel Dai <[EMAIL PROTECTED]> wrote:
> Put build/ivy/lib/Pig/jython-2.5.0.jar in your classpath (if not there, do
> ant first). This is a bug we need to fix.
> Daniel
> Xiaomeng Wan wrote:
>> Hi,
>> I want to write a python udf to split string into bags
>> ------------------------------------------------------------
>> #!/usr/bin/python
>> import re
>> @outputSchema("y:bag{t:tuple(word:chararray)}")
>> def strsplittobag(content,regex):
>>        return re.compile(regex).split(content)
>> ------------------------------------------------------------
>> it gave an error saying "could not instantiate
>> 'org.apache.pig.scripting.jython.JythonFunction' with arguments
>> '[/home/.../mypyudfs.py, strsplittobag]'". I had some other python
>> udfs working, so shouldn't be configuration problem. I am new to
>> python, did I miss anything?
>> Thanks!
>> Shawn
Xiaomeng Wan 2011-01-26, 21:41