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Daniel-AndargeDaniel-Andarge
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caching
1 parent e77af65 commit 2fe690f

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‎0x01-caching/0-basic_cache.py

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#!/usr/bin/python3
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"""
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Module 0-basic_cache
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"""
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from base_caching import BaseCaching
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class BasicCache(BaseCaching):
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"""
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Overrides put() nad self()
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from parent
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"""
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def put(self, key, item):
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"""Add an item in the cache
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"""
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if key and item:
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self.cache_data[key] = item
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def get(self, key):
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"""Get an item by key
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"""
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value = self.cache_data.get(key)
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return value

‎0x01-caching/1-fifo_cache.py

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#!/usr/bin/python3
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"""
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Module 1-fifo_cache.py
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"""
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from base_caching import BaseCaching
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from collections import deque
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class FIFOCache(BaseCaching):
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"""
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Overrides put() nad self()
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from parent
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"""
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def __init__(self):
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"""initialize"""
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super().__init__()
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self.queue = deque([])
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def put(self, key, item):
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"""Add an item in the cache
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"""
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if key and item:
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if len(self.cache_data) == BaseCaching.MAX_ITEMS\
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and key not in self.queue:
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del_key = self.queue.popleft()
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del self.cache_data[del_key]
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print("DISCARD: {}".format(del_key))
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self.cache_data[key] = item
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self.queue.append(key)
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def get(self, key):
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"""Get an item by key
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"""
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value = self.cache_data.get(key)
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return value

‎0x01-caching/100-lfu_cache.py

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#!/usr/bin/python3
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""" 4. MRU Caching
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"""
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from datetime import datetime
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from collections import defaultdict
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BaseCaching = __import__('base_caching').BaseCaching
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class LFUCache(BaseCaching):
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""" BaseCache defines:
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- overwrite functions 'put' and 'get' for implement
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MRU caching system
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"""
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def __init__(self):
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""" Initiliaze
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"""
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super().__init__()
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self.cache_by_time = {}
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self.cache_by_frequency_use = defaultdict(int) # >>> Default value: 0
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def put(self, key, item):
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"""
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Assign to the dictionary self.cache_data the item
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value for the key key
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If the number of items in self.cache_data is higher
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that BaseCaching.MAX_ITEMS:
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- must discard the most recently used item (MRU algorithm)
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- must print DISCARD: with the key discarded and following by
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a new line
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"""
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if key and item:
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self.cache_by_time[key] = datetime.now()
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self.cache_data[key] = item
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self.cache_by_frequency_use[key] += 1
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if len(self.cache_data) > BaseCaching.MAX_ITEMS:
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# Sorted elements by frequency_used
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frequency_use_filtered = {}
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for k, v in self.cache_by_frequency_use.items():
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if k != key:
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frequency_use_filtered[k] = v
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keys_by_frequency_used = sorted(frequency_use_filtered,
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key=frequency_use_filtered.get)
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key_to_delete = keys_by_frequency_used[0]
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# There are more elements with same frequency used count?
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count = frequency_use_filtered[key_to_delete]
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posibles_elements_to_discard_dict = {}
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for k, v in frequency_use_filtered.items():
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if v == count:
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posibles_elements_to_discard_dict[k] = v
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if len(posibles_elements_to_discard_dict) > 1:
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elements_to_discard_by_time = {}
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for k, v in self.cache_by_time.items():
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if k in posibles_elements_to_discard_dict.keys():
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elements_to_discard_by_time[k] = v
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elements_by_time = sorted(
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elements_to_discard_by_time,
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key=elements_to_discard_by_time.get)
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key_to_delete = elements_by_time[0]
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# Delete element with least_frequency_used
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del self.cache_by_time[key_to_delete]
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del self.cache_data[key_to_delete]
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del self.cache_by_frequency_use[key_to_delete]
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print('DISCARD: {}'.format(key_to_delete))
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def get(self, key):
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"""
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Return the value in self.cache_data linked to key
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"""
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element = self.cache_data.get(key)
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if element:
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self.cache_by_time[key] = datetime.now()
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self.cache_by_frequency_use[key] += 1
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return element

‎0x01-caching/2-lifo_cache.py

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#!/usr/bin/python3
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"""
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Module 2-lifo_cache
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"""
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from base_caching import BaseCaching
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class LIFOCache(BaseCaching):
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"""
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Overrides put() nad self()
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from parent
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"""
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def __init__(self):
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"""initialize"""
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super().__init__()
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self.stack = []
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def put(self, key, item):
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"""Add an item in the cache
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"""
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if key and item:
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if len(self.cache_data) == BaseCaching.MAX_ITEMS\
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and key not in self.stack:
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del_key = self.stack.pop()
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del self.cache_data[del_key]
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print("DISCARD: {}".format(del_key))
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self.cache_data[key] = item
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self.stack.append(key)
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def get(self, key):
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"""Get an item by key
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"""
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value = self.cache_data.get(key)
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return value

‎0x01-caching/3-lru_cache.py

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#!/usr/bin/python3
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"""
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Module 3-lru_cache.py
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"""
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from base_caching import BaseCaching
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class LRUCache(BaseCaching):
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"""
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Overrides put() nad self()
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from parent
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"""
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def __init__(self):
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"""initialize"""
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super().__init__()
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self.keys = []
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def put(self, key, item):
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"""Add an item in the cache
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"""
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if key and item:
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if len(self.cache_data) == BaseCaching.MAX_ITEMS\
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and key not in self.keys:
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del_key = self.keys.pop(0)
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del self.cache_data[del_key]
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print("DISCARD: {}".format(del_key))
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if key in self.keys:
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self.keys.remove(key)
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self.cache_data[key] = item
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self.keys.append(key)
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def get(self, key):
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"""Get an item by key
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"""
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if key in self.keys:
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self.keys.remove(key)
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self.keys.append(key)
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value = self.cache_data.get(key)
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return value

‎0x01-caching/4-mru_cache.py

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#!/usr/bin/python3
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"""
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Module 4-mru_cache.py
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"""
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from base_caching import BaseCaching
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class MRUCache(BaseCaching):
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"""
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Overrides put() nad self()
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from parent
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"""
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def __init__(self):
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"""initialize"""
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super().__init__()
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self.keys = []
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def put(self, key, item):
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"""Add an item in the cache
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"""
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if key and item:
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if len(self.cache_data) == BaseCaching.MAX_ITEMS\
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and key not in self.keys:
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del_key = self.keys.pop()
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del self.cache_data[del_key]
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print("DISCARD: {}".format(del_key))
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if key in self.keys:
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self.keys.remove(key)
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self.cache_data[key] = item
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self.keys.append(key)
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def get(self, key):
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"""Get an item by key
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"""
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if key in self.keys:
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self.keys.remove(key)
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self.keys.append(key)
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value = self.cache_data.get(key)
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return value

‎0x01-caching/README.md

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1-
caching
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## 0x01. Caching
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## Goals
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- What a caching system is
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- What FIFO means
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- What LIFO means
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- What LRU means
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- What MRU means
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- What LFU means
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- What the purpose of a caching system
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- What limits a caching system have

‎0x01-caching/base_caching.py

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#!/usr/bin/python3
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""" BaseCaching module
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"""
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class BaseCaching():
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"""BaseCaching defines:
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- constants of your caching system
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- where your data are stored (in a dictionary)
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"""
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MAX_ITEMS = 4
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def __init__(self):
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"""Initiliaze
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"""
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self.cache_data = {}
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def print_cache(self):
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"""Print the cache
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"""
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print("Current cache:")
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for key in sorted(self.cache_data.keys()):
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print("{}: {}".format(key, self.cache_data.get(key)))
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def put(self, key, item):
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"""Add an item in the cache
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"""
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raise NotImplementedError("\
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put must be implemented in your cache class")
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def get(self, key):
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"""Get an item by key
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"""
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raise NotImplementedError("\
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get must be implemented in your cache class")

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