Need a better understanding on how MRO works?

[Steven W. Orr]

Given the following code: (I hope it's as simple as possible) :-)
#! /usr/bin/python
import new
class BASE:
     def __init__( self ):
         print 'Hello from BASE init'
     def m1( self ):
         print 'M1 Base: Self = ', self

def m1replace( self ):
     print 'm1replace:Self = ', self

class D1(BASE):
     def __init__(self):
         BASE.__init__(self)

def __InitDS101Classes():
     name = 'C1'
     nclass = new.classobj(name,(D1,),globals())
     globals()[name] = nclass
     name = 'C2'
     nclass = new.classobj(name,(D1,),globals())
     globals()[name] = nclass
     globals()[name].m1 = m1replace

__InitDS101Classes()

s = C1()
s.m1()
t = C2()
t.m1()

I get the following output:

1100 > ./foo1.py
Hello from BASE init
m1replace:Self =  <__main__.C1 instance at 0xb7e637cc>
Hello from BASE init
m1replace:Self =  <__main__.C2 instance at 0xb7e6388c>

But if I make BASE inherit from object
class BASE(object):
then I get this:

1100 > ./foo1.py
Hello from BASE init
m1replace:Self =  <__main__.NewClass instance at 0xb7f5070c>
Hello from BASE init
M1 Base: Self =  <__main__.D1 instance at 0xb7f5088c>

Can someone please explain why the assignment to C2.m1 would overwrite
BASE.m1?

TIA

-- 
Time flies like the wind. Fruit flies like a banana. Stranger things have  .0.
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steveo at syslang.net