1、散列的映射
Map()创建一个空映射，然后回到一个空映射集合。
在put(key,val)的映射中添加新的键值对。若键已存在，则用新值代替旧值。
get返回key对应的值。如果key不存在，返回none。
del通过del map[key]语句从映射中删除键-值对。
len()回到映射中存储的键-值对的数目。
当键存在时，in通过keyinmap等语句返回True，否则返回False。
2、实例
class Map(object):
def __init__(self,size=11):
self.size = size
self.__slots = [None] * self.size
self.__data = [None] * self.size
def put(self, key, val):
hashvalue = self.hashfunction(key, len(self.__slots))
if self.__slots[hashvalue] == None:
self.__slots[hashvalue] = key
self.__data[hashvalue] = val
else:
if self.__slots[hashvalue] == key:
self.__data[hashvalue] = val
else:
nextslot = self.rehash(hashvalue, len(self.__slots))
while self.__slots[nextslot] != None and self.__slots[nextslot] != key:
nextslot = self.rehash(nextslot, len(self.__slots))
if self.__slots[nextslot] == None:
self.__slots[nextslot] = key
self.__data[nextslot] = val
else:
self.__data[nextslot] = val
def get(self, key):
startslot = self.hashfunction(key, len(self.__slots))
data = None
stop = False
found = False
position = startslot
while self.__slots[position] != None and \
not found and not stop:
if self.__slots[position] == key:
found = True
data = self.__data[position]
else:
position = self.rehash(position, len(self.__slots))
if position == startslot:
stop = True
return data
def delete(self,key):
pass
def __getitem__(self, key):
return self.get(key)
def __setitem__(self, key, val):
self.put(key, val)
def __delitem__(self, key):
self.delete(key)
def len(self):
pass
def hashfunction(self, key, size):
return key % size
def rehash(self, oldhash, size):
return (oldhash + 1) % size以上就是python哈希散列的映射，希望对大家有所帮助。更多Python学习指路：python基础教程
