Viewing file:  Util.py (1.16 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
class ListRedirect(object):
"""
A utility class for lists of items joined by an operator. ListRedirects with length 1
are a special case and are considered equivalent to the item instead of a list containing it.
The reduce function is used for normalizing ListRedirect to the single item (and calling reduce on it recursively)
"""
reducable = True
def __getattr__(self, attr):
if hasattr(self._list, attr):
return getattr(self._list, attr)
raise AttributeError, '%s has no such attribute %s' % (repr(self), attr)
def __iter__(self):
for i in self._list:
yield i
def reduce(self):
if self.reducable and len(self._list) == 1:
singleItem = self._list[0]
if isinstance(singleItem,ListRedirect):
return singleItem.reduce()
else:
return singleItem
else:
return type(self)([isinstance(item,ListRedirect) and item.reduce() or item for item in self._list])
#Utility function for adding items to the front of a list
def ListPrepend(item,list):
#print "adding %s to front of %s"%(item,list)
return [item] + list
|