#format wiki
#language en
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= Core Jython / Python Examples =

DocumentationAndEducation

<<TableOfContents>>

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Examples related to core Jython / Python will be here. Intended for those new to Python / Jython

== Print ==
Print Hello world
{{{#!python
print 'Hello World' 
print "Hello World"
}}}

== JArray ==

I was curious on how to work with jarray and move the arrays between classes after being filled with values and operated. I think this example explains some of the basics. Of course, there are more pythonic ways to do this. Cheers! Alfonso Reyes 

{{{#!python
from java.lang import Math
from jarray import array, zeros
import java.util.Random;

class ArrayClass:
    """    This class will fill an array with random numbers
    and then return the array for further operations
    """
    def __init__(self, elems):
        self.N = elems
        systemEnergy = 0.0025
        self.v = zeros(self.N, "d")     # array of zeros, double type
        v0 = Math.sqrt(2.0 * systemEnergy / self.N)
        for i in range(self.N):
            r = java.util.Random()
            self.v[i] = v0 * r.nextInt(self.N)  # same velocity for all particles

    def out(self):
        for i in range(self.N):
            print i, self.v[i]

    def get(self):
        return self.v

n = 100
uarr = zeros(n, "d")    # array of double to store some operations
ac = ArrayClass(n)      
ac.out()                # print the array
arr = ac.get()          # get the array to start doing some work on it

# get a first third of the array members and times 10
print "Get a first third of the array members"
for i in range(n/3):
    uarr[i] = arr[i] * 10
    print i, arr[i], uarr[i]
}}}

== Multidimensional 2-D String Array ==
In case you need 2-D string arrays this example may help you to start. Cheers! Alfonso Reyes, Houston-Texas

{{{#!python
from java.lang.reflect import Array
import java

rows = 3
cols = 3

str2d = java.lang.reflect.Array.newInstance(java.lang.String,[rows, cols])
str2d[0][0] = "python"
str2d[1][0] = "jython"
str2d[2][0] = "java"

str2d[0][1] = "syntax "
str2d[1][1] = "strength"
str2d[2][1] = "libraries"

str2d[0][2] = "unclutter"
str2d[1][2] = "combine"
str2d[2][2] = "graphics"

print str2d

print "printing multidimensional array"
for i in range(len(str2d)):
    for j in range(len(str2d[i])):
        print str2d[i][j]+"\t",
    print
print
}}}

== Finding methods in a python script ==

Posted on the Jython list March 18, 2008:

This will give you name-method pairs; if you just want the names, call
keys() on it.  

{{{
import inspect

def _is_some_method(object):
    return inspect.ismethod(object) or inspect.ismethoddescriptor(object)

def allmethods(cl):
    methods = {}
    for key, value in inspect.getmembers(cl, _is_some_method):
        methods[key] = 1
    for base in cl.__bases__:
        methods.update(allmethods(base)) # all your base are belong to us
    for key in methods.keys():
        methods[key] = getattr(cl, key)
    return methods

}}}
Usage example:
{{{
>>> allmethods(str).keys()
['__unicode__', 'rjust', 'center', 'endswith', 'decode', 'translate', 'lower', 'encode', 'isunicode', '__setattr__', '__rmul__', '__add__', '__str__', 'istitle', 'lstrip', 'join', '__reduce_ex__', 'startswith', 'isalnum', 'rstrip', '__getattribute__', '__getslice__', '__eq__', '__init__', '__mod__', 'isupper', '__len__', 'rindex', 'isalpha', 'replace', '__ne__', 'strip', 'isspace', 'swapcase', 'split', 'isnumeric', 'capitalize', 'rfind', '__getitem__', '__contains__', 'title', '__ge__', 'index', '__repr__', 'ljust', 'islower', '__le__', 'isdecimal', 'expandtabs', '__delattr__', 'find', 'splitlines', 'count', 'upper', '__gt__', '__reduce__', 'isdigit', '__lt__', 'zfill', '__cmp__', '__mul__', '__hash__']
}}}