Muhammad Alkarouri schrieb:
I was having a go at a simple implementation of Maybe in Python when I
stumbled on a case where x.__mul__(y) is defined while x*y is not.
class Maybe(object):
def __init__(self, obj):
self.o = obj
def __repr__(self):
return 'Maybe(%s)' %
Gabriel Genellina schrieb:
http://docs.python.org/reference/datamodel.html#special-method-lookup-for-new-style-classes
Ok. That explains a lot. And your explanation tells the rest. Thank you.
In short, you have to define the __mul__ method on the type itself or
any of its bases.
I found this,
Hi everyone,
I was having a go at a simple implementation of Maybe in Python when I
stumbled on a case where x.__mul__(y) is defined while x*y is not.
The class defining x is:
class Maybe(object):
def __init__(self, obj):
self.o = obj
def __repr__(self):
return
Muhammad Alkarouri wrote:
Hi everyone,
I was having a go at a simple implementation of Maybe in Python when I
stumbled on a case where x.__mul__(y) is defined while x*y is not.
The class defining x is:
class Maybe(object):
def __init__(self, obj):
self.o = obj
def
En Mon, 19 Oct 2009 21:31:44 -0300, Muhammad Alkarouri
malkaro...@gmail.com escribió:
I was having a go at a simple implementation of Maybe in Python when I
stumbled on a case where x.__mul__(y) is defined while x*y is not.
__special__ methods are searched in the type, not in the instance
Muhammad Alkarouri schrieb:
Traceback (most recent call last):
File pyshell#83, line 1, in module
x*7
TypeError: unsupported operand type(s) for *: 'Maybe' and 'int'
The farthest I can go in this is that I presume that __mul__ (as
called by operator *) is supposed to be a bound
Gabriel Genellina schrieb:
__special__ methods are searched in the type, not in the instance
directly. x*y looks for type(x).__mul__ (among other things)
So I thought too, but:
class meta(type):
def __mul__(*args):
return 123
class boo(object):
__metaclass__ = meta
print
