Hashing Table in Python

Question

I just want your opinion about that code! :)

import random
class Error(Exception):
 def __init__(self, error=None):
 self.error = error
 def __str__(self):
 return str(self.error)
class HashTable(object):
 def __init__(self):
 self.length = 20
 self.keys = []
 self.table = [[] for _ in range(self.length)]
 def __len__(self):
 return self.length
 def __setitem__(self, key, value):
 self.keys.append(key)
 hashed_key = self._hash(key)
 self.table[hashed_key].append((value)) #Wartosc jest dodawana do listy pod hashowanym indeksem
 
 def _hash(self, key) :
 return hash(key) % self.length
 
 def show_list(self):
 return self.table
 
 def __getitem__(self, key):
 for el in self.table[self._hash(key)]:
 if el[0] == key:
 return el[1]
 
 def __delitem__(self, key):
 for el in self.table[self._hash(key)]:
 if el[0] == key:
 self.table[self._hash(key)].remove(el)
 
 def __iter__(self):
 def Generator(data):
 mylist = [_ for _ in data]
 for i in mylist:
 yield i
 return Generator(self.table)
 
L = HashTable()
content = []
with open("song.txt", 'r', encoding = 'utf8') as travis:
 for line in travis:
 for word in line.split():
 content.append(word)
for c in content:
 L[c] = c
 
for x in L:
 print(x)

I've also will be really greateful for any tips and how to improve this one! :D

• Reinderien: I'm going to assume that you're not using a built-in dictionary for learning purposes etc., but that would greatly simplify this code.

Answer 1

My opinion is that you should test better, before asking for code review.

line = " #Wartosc jest dodawana do listy pod hashowanym indeksem"
for word in line.split():
 content.append(word)
for c in content:
 L[c] = c
print(L["jest"])

Put a print statement inside each of your functions, for example print('__getitem__ ran'). Then keep modifying your test code until you see all of them. Right now you are not using all your methods.

Edit: Also, this is not really something I will code review once tested. The correct review is to replace it with:

HashTable = dict

Both the readability and efficiency are miles better than yours!