Still the __new__ hell ...

[Paulo da Silva]

Sorry to put here too many questions about __init__ __new__
stuff but I always found a new problem when using them.
I have searched for simple __new__ docs on how to do the
basic things but find none.

After trying the solutions people gently posted here
(thanks) I run into new trouble when I go with further
development.

Here is the new situation.

As suggested in a previous post, I used __new__ to
subclass date class but now cPickle/pickle loads
does not work.

from datetime import date
import cPickle,string

class MyDate(date):
	def __new__(cls,year,month=None,day=None):
		if type(year) is str:
			year,month,day=map(int,string.split(year,'-'))
		if year<100:
			year+=2000
		return date.__new__(cls,year,month,day)

class C1(object):
	def __init__(self):
		self.x=MyDate("2007-3-15")

	def f(self):
		print self.x

c1=C1()

d=cPickle.dumps(c1)
c2=cPickle.loads(d)
c2.f()

1. year is passed to __new__ as a string but with invalid
contents!

2. If I had a __new__ in class C1, cPickle.loads invokes it
with only one parameter. This forces to allow __new__ accept
only 1 parameter (cls) which I don't want for the normal
situation.

Thanks for your patience.
Paulo