import module error: calling python script using jython in a java program

I am trying to execute a python file from netbeans using jython in a java program. My code is like this:

PythonInterpreter.initialize(System.getProperties(), System.getProperties(), 
                             new String[0]);
PythonInterpreter interp = new PythonInterpreter();
interp.execfile("as1.py");

error is:

Traceback (most recent call last):
  File "as1.py", line 2, in <module>
    import datetime
ImportError: No module named datetime

and also interdependent python files also not importing those are in same directory.

like:

PythonInterpreter.initialize(System.getProperties(), System.getProperties(), new String[0]);
PythonInterpreter interp = new PythonInterpreter();
interp.execfile("calen.py");

python files are:

calen.py:

from as1 import * 
print ( "I am printing" + str(Moh(1000).run()))

as1.py:

from time import time
import datetime
class Moh:
    def __init__(self, n):  
        self.n = n

    def run(self):
        data = [1,2,3,4,5]
        start = time()
        for i in range(self.n):
            data.append(i)
        end = time()
        return ( end - start )/self.n

if __name__ == "__main__":
    print ( "I am printing" + str(Moh(1000).run()))

error is:

Traceback (most recent call last):
  File "calen.py", line 1, in <module>
    from as1 import * 
ImportError: No module named as1