def remove(self, obj):
"""
Remove a spcific entry(obj) form the hashtable
:param obj: the entry being removed
:return: the removed entry
"""
if self.contains(obj):
if self.sizeOff():
self.rehash()
toRemoved = ChainNode(obj)
key = toRemoved.getKey(self._capacity)
temp = self._list[key]
temp_back = temp
# if the entry to be removed is the first item in this linked list
if str(temp) == obj:
self._list[key] = self._list[key].getChain()
temp.setChain(None)
# else the entry to be removed is in other position than the first
else:
while not temp.getChain() is None:
temp = temp.getChain()
if str(temp) == obj:
temp_back.setChain(temp.getChain())
temp.setChain(None)
break
temp_back = temp_back.getChain()
# if the entry to be removed is the only one left in hashtable
if temp.getPrevious() is None and temp.getLink() is None:
self._front = None
self._back = None
# if the entry to be removed is front
elif temp.getPrevious() is None:
self._front = temp.getLink()
temp.getLink().setPrevious(None)
temp.setLink(None)
# if the entry to be removed is back
elif temp.getLink() is None:
self._back = temp.getPrevious()
temp.getPrevious().setLink(None)
temp.setPrevious(None)
# if the entry to be removed is in the middle
else:
temp.getPrevious().setLink(temp.getLink())
temp.getLink().setPrevious(temp.getPrevious())
temp.setPrevious(None)
temp.setLink(None)
self._size -= 1
return temp
def contains(self, obj):
"""
Check if an entry(obj) is in hashtable
:param obj: the entry being checked
:return: true if this entry is found
"""
toSearch = ChainNode(obj)
key = toSearch.getKey(self._capacity)
temp = self._list[key]
if self._list[key] is None:
return False
elif str(temp) == obj:
return True
else:
while not temp.getChain() is None:
temp = temp.getChain()
if str(temp) == obj:
return True
return False