Jython tip

Hidden variables

 that's two leading underscores
For example:
class MyClass:

__attr = 10 # private class attribute

def method1(self):

pass

def method2(self, p1, p2):

pass

def __privateMethod(self, text):

self.__text = text # private attribute

instance constructor

class Class1:

def __init__ (self): # no arguments

self.data = [] # set implicit data

class Class2:

def __init__ (self, v1, v2): # 2 required arguments

self.v1 = v1 # set data from parameters
self.v2 = v2

class Class3:

def __init__ (self, values=None): # 1 optional argument

if values is None: values = []
self.values = values # set data from parameter