Looking for a list subclassing example...
Mike C. Fletcher
mcfletch at rogers.com
Tue Jun 4 12:03:57 EDT 2002
Well, here's a generic list-subclass example...
class rlist( list ):
"""Sub-class of list which calls a method before any addition is
allowed"""
def __setslice__( self, start, stop, value ):
"""__setslice__ with value checking"""
value = self.beforeMultipleAdd([ self.beforeAdd(item) for item
in value ])
return list.__setslice__( self, start, stop, value )
def extend( self, value ):
"""extend with value checking"""
value = self.beforeMultipleAdd([ self.beforeAdd(item) for item
in value ])
return list.extend( self, value )
__iadd__ = extend
def append( self, value ):
"""append with value checking"""
value = self.beforeAdd( value )
return list.append( self, value )
def insert( self, index, value ):
"""insert with value checking"""
value = self.beforeAdd( value )
return list.insert( self, index, value )
def __setitem__( self, index, value ):
"""__setitem__ with value checking"""
value = self.beforeAdd( value )
return list.__setitem__( self, index, value )
def beforeAdd( self, value ):
"""Called before all attempts to add an item"""
return value
def beforeMultipleAdd( self, value ):
"""Called before attempts to add more than one item (beforeAdd
has already be called for each item)"""
return value
HTH,
Mike
Shagshag13 wrote:
> Hello,
>
> I'm looking for a list subclassing example, and i can't find it...
>
> Do you have one to show ?
>
> Thanks,
>
> s13.
>
>
>
--
_______________________________________
Mike C. Fletcher
http://members.rogers.com/mcfletch/
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