Re: Overloading __init__ & Function overloading

Iyer, Prasad C wrote: 
Thanks a lot for the reply.
But I want to do something like this

class BaseClass:
	def __init__(self):
		# Some code over here
	def __init__(self, a, b):
		# Some code over here
	def __init__(self, a, b, c):
		# some code here

baseclass1=BaseClass()
baseclass2=BaseClass(2,3)
baseclass3=BaseClass(4,5,3)

In my experience, the vast majority of cases where you "want" function overloading, you really just want sensible default parameters. Since Python is dynamically typed, the other common use case in static-typed language (to provide f(int,int), f(float,float), f(double,complex), f(Momma,Poppa) equivalents) is entirely unnecessary.

Try:

class BaseClass:
   def __init__(self, a = None, b = None, c = None):
      if a == None:
         <etc>

or (if you want to take any number of parameters)

class BaseClass:
   def __init__(self, *args):
      if len(args) == 0:
         <etc>

Of course, this is assuming that the behaviour is radically different based on the number of arguments, which is generally Poor Design. You probably _REALLY_ want:

class BaseClass:
def __init__(self, a=SensibleDefault1, b=SensibleDefault2, c=SensibleDefault3):
<etc>

As a concrete example of this, consider:

class Point:
   def __init__(self, x=0, y=0, z=0):
      <etc>

Then you can call it with:
originPoint = Point()
pointInX = Point(xloc)
pointInXYPlane = Point(xloc,yloc)
pointIn3DSpace = Point(xloc,yloc,zloc)
<note, normally I loathe CaMeLcAsE, but it's readable in this context>

Or if the Defaults aren't quite so simple, and sensible defaults depend on previous values, use:

class BaseClass:
   def __init__(self, a=SensibleDefault1, b=None, c=None):
      if b==None:
         b = stuff_involving(a)
      if c==None:
         c = stuff_involving(a,b)
      <etc>
.