Importing python modules in jython

Question

I'm having some issues importing scapy under jython. I've been doing java forever, but python for only a day or two.

The simple case to reproduce the problem is:

$jython

>>> import sys
>>> sys.path
['', '/usr/share/jython/Lib', '/usr/lib/site-python', '__classpath__']
>>> from scapy.all import *
Traceback (innermost last):
File "<console>", line 1, in ?
ImportError: no module named scapy

If I do these exact same steps under python, everything works. How do I tell jython to use scapy? If it helps, I'm running ubuntu 10.04 and installed jython and scapy via apt-get install

Solution 1

You've done the right thing printing sys.path. Now you should go to your python shell, and do this:

$ python
>>> import scapy
>>> print scapy.__file__

This will show where scapy is being imported from. The most likely problem is that your jython sys.path doesn't include the directory containing scapy.

Solution 2

You can do the easy_install for jython.

Run:

jython ez_setup.py 

from http://peak.telecommunity.com/dist/ez_setup.py

Then you will get a easy_install script under your jython/bin go there and

jython easy_install scapy

(or whatever module you need)

Then next time you startup jython you will be able to import it.

Comments

[Amala]

I had an issue under tomcat where I had to do a 'import site' first

[user323094]

The official docs are here: jython.org/jythonbook/en/1.0/…

[BoltzmannBrain]

So how then can the directory for python packages get added to the jython sys.path?

[Aminah Nuraini]

In my case, I had to use jython ez_setup.py scapy instead

[Micha93]

What good is that going to do me? I can use the PYTHONPATH and then it works to import modules. What doesn't work is that the imported module can import other modules.