system-design-primer/solutions/object_oriented_design/hash_table/hash_map.py
2017-03-03 18:53:41 -08:00

38 lines
1.1 KiB
Python

class Item(object):
def __init__(self, key, value):
self.key = key
self.value = value
class HashTable(object):
def __init__(self, size):
self.size = size
self.table = [[] for _ in range(self.size)]
def _hash_function(self, key):
return key % self.size
def set(self, key, value):
hash_index = self._hash_function(key)
for item in self.table[hash_index]:
if item.key == key:
item.value = value
return
self.table[hash_index].append(Item(key, value))
def get(self, key):
hash_index = self._hash_function(key)
for item in self.table[hash_index]:
if item.key == key:
return item.value
raise KeyError('Key not found')
def remove(self, key):
hash_index = self._hash_function(key)
for index, item in enumerate(self.table[hash_index]):
if item.key == key:
del self.table[hash_index][index]
return
raise KeyError('Key not found')