import collections
class OrderedSet(collections.MutableSet):
KEY, PREV, NEXT = range(3)
def __init__(self, iterable=None):
self.end = end = []
end += [None, end, end] # sentinel node for doubly linked list
self.map = {} # key --> [key, prev, next]
if iterable is not None:
self |= iterable
def __len__(self):
return len(self.map)
def __contains__(self, key):
return key in self.map
def add(self, key):
if key not in self.map:
end = self.end
curr = end[self.PREV]
curr[self.NEXT] = end[self.PREV] = self.map[key] = [key, curr, end]
def discard(self, key):
if key in self.map:
key, prev, next = self.map.pop(key)
prev[self.NEXT] = next
next[self.PREV] = prev
def __iter__(self):
end = self.end
curr = end[self.NEXT]
while curr is not end:
yield curr[self.KEY]
curr = curr[self.NEXT]
def __reversed__(self):
end = self.end
curr = end[self.PREV]
while curr is not end:
yield curr[self.KEY]
curr = curr[self.PREV]
def pop(self, last=True):
if not self:
raise KeyError('set is empty')
key = next(reversed(self)) if last else next(iter(self))
self.discard(key)
return key
def __repr__(self):
if not self:
return '%s()' % (self.__class__.__name__,)
return '%s(%r)' % (self.__class__.__name__, list(self))
def __eq__(self, other):
if isinstance(other, OrderedSet):
return len(self) == len(other) and list(self) == list(other)
return set(self) == set(other)
def __del__(self):
self.clear() # remove circular references
if __name__ == '__main__':
print(OrderedSet('abracadaba'))
print(OrderedSet('simsalabim'))
x = OrderedSet('abracadaba')
# doesn't raise "Exception TypeError: TypeError('list indices must be integers, not NoneType',) in ignored"
Diff to Previous Revision
--- revision 1 2011-03-24 10:55:46
+++ revision 2 2011-08-12 14:15:20
@@ -1,8 +1,8 @@
import collections
-KEY, PREV, NEXT = range(3)
-
class OrderedSet(collections.MutableSet):
+
+ KEY, PREV, NEXT = range(3)
def __init__(self, iterable=None):
self.end = end = []
@@ -20,28 +20,28 @@
def add(self, key):
if key not in self.map:
end = self.end
- curr = end[PREV]
- curr[NEXT] = end[PREV] = self.map[key] = [key, curr, end]
+ curr = end[self.PREV]
+ curr[self.NEXT] = end[self.PREV] = self.map[key] = [key, curr, end]
def discard(self, key):
if key in self.map:
key, prev, next = self.map.pop(key)
- prev[NEXT] = next
- next[PREV] = prev
+ prev[self.NEXT] = next
+ next[self.PREV] = prev
def __iter__(self):
end = self.end
- curr = end[NEXT]
+ curr = end[self.NEXT]
while curr is not end:
- yield curr[KEY]
- curr = curr[NEXT]
+ yield curr[self.KEY]
+ curr = curr[self.NEXT]
def __reversed__(self):
end = self.end
- curr = end[PREV]
+ curr = end[self.PREV]
while curr is not end:
- yield curr[KEY]
- curr = curr[PREV]
+ yield curr[self.KEY]
+ curr = curr[self.PREV]
def pop(self, last=True):
if not self:
@@ -63,7 +63,9 @@
def __del__(self):
self.clear() # remove circular references
-
+
if __name__ == '__main__':
print(OrderedSet('abracadaba'))
print(OrderedSet('simsalabim'))
+ x = OrderedSet('abracadaba')
+ # doesn't raise "Exception TypeError: TypeError('list indices must be integers, not NoneType',) in ignored"
