python中怎么实现一个zset数据结构
本篇文章为大家展示了python中怎么实现一个zset数据结构,内容简明扼要并且容易理解,绝对能使你眼前一亮,通过这篇文章的详细介绍希望你能有所收获。
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下面上代码。
#coding=utf-8 from bisect import bisect_left,bisect_right,insort #定义节点 class SNode: def __init__(self,key=None, score=float('-inf'),next=None): self.key = key self.score = score def __lt__(self,other): return self.score < getattr(other,'score',other) def __gt__(self,other):#没定义__gt__的话会导致bisect_right出问题,即使已经定义了__lt__ return self.score > getattr(other,'score',other) #定义数组,用bisect维护顺序 class Slist(object): def __init__(self): self.key2node = {} self.card = 0 self.orderlist = [] def findpos(self, snode): curpos = bisect_left(self.orderlist,snode) while 1: if self.orderlist[curpos].key==snode.key: break curpos += 1 return curpos def insert(self,key,score): if not isinstance(score,int):raise Exception('score must be integer') snode = self.key2node.get(key) if snode: if score == snode.score: return 0 del self.orderlist[self.findpos(snode)] snode.score = score else: self.card += 1 snode = SNode(key=key,score=score) self.key2node[key] = snode insort(self.orderlist, snode) return 1 def delete(self,key): snode = self.key2node.get(key) if not snode: return 0 self.card -= 1 del self.orderlist[self.findpos(snode)] del self.key2node[key] del snode return 1 def search(self,key): return self.key2node.get(key) class SortedSet: def __init__(self): self.slist = Slist() def zadd(self, key, score): return self.slist.insert(key, score) def zrem(self, key): return self.slist.delete(key) def zrank(self, key):#score相同则按字典序 snode = self.slist.key2node.get(key) if not snode: return None return self.slist.findpos(snode) def zrevrank(self, key): return self.zcard - 1 - self.zrank(key) def zscore(self, key): snode = self.slist.key2node.get(key) return getattr(snode,'score',None) def zcount(self, start, end): ol = self.slist.orderlist return bisect_left(ol,end+1) - bisect_right(ol,start-1) @property def zcard(self): return self.slist.card def zrange(self, start, end, withscores=False):#score相同则按字典序 nodes = self.slist.orderlist[start: end+1] if not nodes:return [] if withscores: return [(x.key, x.score) for x in nodes] else: return [x.key for x in nodes] def zrevrange(self, start, end, withscores=False): card = self.zcard if end<0: end = end + card if start<0: start = start + card nodes = self.slist.orderlist[max(card-end-1, 0): max(card-start, 0)][::-1] if not nodes:return [] if withscores: return [(x.key, x.score) for x in nodes] else: return [x.key for x in nodes] def zrangebyscore(self, start, end, withscores=False): ol = self.slist.orderlist nodes = ol[bisect_left(ol, start):bisect_right(ol, end)] if not nodes:return [] if withscores: return [(x.key, x.score) for x in nodes] else: return [x.key for x in nodes] def zrevrangebyscore(self, end, start, withscores=False): return self.zrangebyscore(start, end, withscores)[::-1] def zincrby(self, key): snode = self.slist.key2node.get(key) if not snode: return self.zadd(key, 1) score = snode.score self.zrem(key) return self.zadd(key, score+1) import contextlib import time timeobj = {} class timetrace: @contextlib.contextmanager def mark(self,name): t = time.time() yield timeobj[name] = time.time() - t def stat(self): print '---------benchmark(100000 requests)---------' for k,v in timeobj.iteritems(): print '{} {}s'.format(k,v) tt = timetrace() if __name__ == '__main__': s = SortedSet() s.zadd('kzc',17) s.zadd('a',1) s.zadd('b',2) s.zadd('c',2) s.zadd('d',6) s.zadd('hello',18) s.zadd('world',18) s.zincrby('kzc') print 'kzc score',s.zscore('kzc') print 'kzc rank',s.zrank('kzc') print 'kzc revrank',s.zrevrank('kzc') print 'zcount(1,20)',s.zcount(1,20) print 'zrange(2,4,withscores=True)',s.zrange(2,4,withscores=True) print 'zrangebyscore(1,5,withscores=True)',s.zrangebyscore(1,5,withscores=True) print 'zrem("c")',s.zrem('c') print 'zrangebyscore(1,5,withscores=True)',s.zrangebyscore(1,5,withscores=True) print 'zcard',s.zcard print 's.zadd("c",7)',s.zadd('c',7) print 'zcard',s.zcard print 'zrevrange all',s.zrevrange(0,-1,withscores=True) #benchmark import random keys = [str(x) for x in range(0,100000)] values = range(0,100000) random.shuffle(keys) with tt.mark('zadd'): map(lambda x,y:s.zadd(x,y),keys,values) with tt.mark('zscore'): map(s.zscore,keys) with tt.mark('zrank'): map(s.zrank,keys) tt.stat()
结果截图如下:
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