AW: AW: AW: [Jython-users] Import doesn't work (yet, but my script does!)

[Joern E. <Joe...@mi...>]

Hi all, hi Robert

<snip>
>>> [Robert]
>>> 1. is python.home set so that it actually finds and reads the registry?
>>
>> [Joern]
>>
>> I don't know. How do I find out? The whole Jython-related code is 
"hidden"
>> within a jar-file. No chance to dip into it.
>
> >>> import java
> >>> java.lang.System.getProperty("python.home")
>
> Also add...
>
> >>> import sys
> >>> print sys.path, sys.prefix
>
> Knowing these three values is the best first step

I've done so and now my script looks like this:

# ----------- begin ob script
import java
java.lang.System.getProperty("python.home")
java.lang.System.getProperty("python.path")

import sys
sys.path.append("c:\\program files\\jython;c:\\program files\\jython\\lib")

print "python.home: ",java.lang.System.getProperty("python.home")
print "python.path: ",java.lang.System.getProperty("python.path")
print "sys.path: ",sys.path
print "sys.prefix: ",sys.prefix

# Import support for strings
import string

# Get the value of the scalar node
value = scriptinterface.getNodeValue(".1.3.6.1...")

# Convert value to INT
valueAsInt=string.atoi(value)

# Add 1 to value
valueAsInt=valueAsInt+1

# Set a limit of 8 for value
if valueAsInt > 8:
	valueAsInt=1

# Convert valueAsInt back to string
value=str(valueAsInt)

# Write back (increased) value to node
scriptinterface.updateValue(".1.3.6.1...",value,"CONST")
# ----------- end ob script



And this is how the log-file looks right after executing the script:

<snip>
...
python.home:  None
python.path:  None
sys.path:  ['.\\jars\\Lib', 'c:\\program files\\jython;c:\\program 
files\\jython\\lib']
sys.prefix:  .\jars\
Traceback (innermost last):
  File 
"D:\AdventNet\simulator\mibs\_behavior_scripts_\counter_with_import.py", 
line 14, in ?
ImportError: no module named string
Exception while executing the Python Script


'python.home' is not set, therefore 'registry' could not be read and 
'python.path' isn't set accurately, right? 'sys.path' is correct - the 
'.\\jars\\Lib' is the path leading to the jars containing all the 
class-files of the AgentSimulator. The module 'string.py' actually is 
present at 'c:\program files\jython\lib'. Doesn't it indicate the path to 
the modules is missing? Does jython use sys.path as well as python.path?

> Is fpformat is the import error you originally saw? if so, it may be that
> you need to copy that module from the CPython distribution into your
> Jython Lib directory.

Yes, the import error happens when I try to import fpformat, too, but 
'fpformat.py' actually is present in the Jython lib directory 'c:\program 
files\jython\lib\'. I guess it's because of the missing 'python.path'.

> <snip>
>> # ---------- start of noneworking script
>> from org.python.util import PythonInterpreter
>> from java.util import Properties
>> from java.lang import System
>
> re-initializing is probably the wrong way to go here. If you are running
> something in Jython and need to import modules from a specific directory,
> it is better to use:
>
> >>> import sys
> >>> sys.path.append("\\the\\required\\directory")
>
> instead of:
>> props = Properties()
>> props.setProperty("python.path", "c:\Program Files\Jython;c:\Program
>> Files\Jython\lib")
>> PythonInterpreter.initialize(System.getProperties(), props, "")

Hmmm ... because this will delete the old path that I may need further!?

> Also make sure that the module does in fact live in one of the 
directories
> in sys.path.
>
> Side note: The 3rd arg to initialize should be [""] - it needs to convert
> to a String[] rather than just a String.  However, the error message
> indicates other problems...
>
>> # Import support for strings
>> import string
>>
>> # Get the value of the scalar node
>> value = scriptinterface.getNodeValue(".1.3.6.1...")
>>
>> # Convert value to INT
>> valueAsInt=string.atoi(value)
>>
>> # Add 1 to value
>> valueAsInt=valueAsInt+1
>>
>> # Set limit for value to 256. If reached reset value to 1.
>> if valueAsInt > 256:
>> 	valueAsInt=1
>>
>> # Convert valueAsInt back to string
>> value=str(valueAsInt)
>>
>> # Write back (increased) value to node
>> scriptinterface.updateValue(".1.3.6.1...",value,"CONST")
>> # ---------- end of noneworking script
>
> This script could be written as:
>
> value = int( scriptinterface.getNodeValue(".1.3.6.1...") )
> value = value > 255 and "1" or str(value + 1)
> scriptinterface.updateValue(".1.3.6.1...",value,"CONST")
>
> read the second line as: if value + 1 > 256, return "1" for the
> expression, else return value + 1 as a string.

I know the script could be coded more compact but it's example-code for my 
colleagues so I left it more detailed for them.

>> The scripts were executed by the AgentSimulator at runtime whereat the
>> condition the script will be started can be chosen freely (requestBased,
>> timerBased, thresholdBased). How, why and were the script will be 
started
>> can't be seen at all - the whole jython-stuff is "hidden" in a jar. The
>> AgentSimulators' logfile contains this after executing the (noneworking)
>> script:
>>
>> Traceback (innermost last):
>>   File "D:\AdventNet\simulator\mibs\_behavior_scripts_\counter.py", line 
7,
>> in ?
>> AttributeError: class 'org.python.util.PythonInterpreter' has no 
attribute
>> 'initialize'
>> Exception while executing the Python Script
>
> My guess is that the error message above indicates initialize has been
> modified/renamed. No matter, I don't think it is what you are after
> anyway.
>
>> I'm wondering how this can happen, because using System.getProperties() 
is
>> absolutely similar to using PythonInterpreter.initialize() or am I wrong
>> somehow?
>
> Initialize is all about establishing system state information from system
> properties, registry properties and the new properties specified in the
> 2nd arg. So it is not really like getProperties. If jython is already
> running, however, intialize is trying to re-initialize things, which
> isn't really effective.
>
>> And 'initialize' isn't an attribute but a method.
>
> In the Python world, anything in a class is an attribute. The error
> message you see is a Jython error- not a Java error, so it is the correct
> error message to report only if "initialize" truly does not exist in your
> PythonInterpreter class. Check dir(PythonInterpreter) a few times to see
> if "initialize" is really there, or if it has been modified. Note that
> this is only to explain the error, I still don't think you want 
initialize
> for your situation  :)

PythonInterpreter.initialize in fact is present. Just look at the example 
below. 'inizialize' is a typo. It actually _is_ 'initialize'. Sorry. The 
disatvantage is that we don't know which changes the programers from 
AdventNet made.

>> From my point of
>> view this should work fine, but as you can see it doesn't. It looks like
>> the path to the libs can't be found as before. I've set the correct path
>> within the file 'registry'. Using a DOS-Box behaves the same way:
>>
>> (Inside the DOS-Box, again.)
>> C:\>jython
>> Jython 2.0 on java1.3.0 (JIT: null)
>> Type "copyrigth", ... etc.
>> >>> from org.python.util import PythonInterpreter
>> >>> PythonInterpreter.initialize("old", "new", "")
>> Traceback (innermost last):
>>   File "<console>", line 1, in ?
>> AttributeError: class 'org.python.util.PythonInterpreter' has no 
attribute
>> 'initialize'
>> >>> dir(PythonInterpreter)
>> ['err', 'eval', 'exec', 'execfile', 'get', 'getLocale', 'inizialize',
>> 'locals', 'out', 'set', 'setErr', 'setLocals', 'setOut']
>
> Is 'inizialize' a typo in the mail, or does the dir really and truly
> report 'inizialize'.  If it really and truly says 'inizialize', your
> results make more sense.
>
> <snip>
>> May jython has to be started with the -D option?
>
> "has to"? - no.  You may use the -D option to start java applications 
that
> embed Jython. This allows the setting of properties from the 
command-line.
> Look at the jython.bat file for example.  If your embedded Jython
> application that is giving you trouble implements initialize like
> org.python.util.jython does, you may be able to force certain
> properties with -D.  For example:
>
> java -cp \path\to\jython.jar -Dpython.hom="c:\my\Jython\home\dir" \
> -Dpython.path="c:\some\dir" org.python.util.jython
>
> This starts Jython with a specific python.home and python.path. Other
> Java apps that embed Jython and use the
> PythonInterpreter.initialize(System.getProperties(), props, new 
String[0])
> should also make use of the -D options (unless they specifically override
> these options in the props values internally). My thought was that the
> application you are working with could merely be started with a
> -Dpython.path="\\some\\path" to add the path you desired to sys.path. But
> I misunderstood the situation.

<snip>

> Cheers,
> Robert

Bye
Joern