提交第五章作业

Author: Monalissaa

Diff for: Homework/mona/lz_episode_05/LRU.png

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+import time
+import pickle  # 将数据序列化
+import hashlib  # 得到序列化数据后的字符串
+import functools  # 保留原函数的属性
+
+
+class Node:  # 根据LRU的特性制作一个链表
+    def __init__(self, key, value, time, pre=None, nxt=None):
+        self.key = key
+        self.value = value
+        self.pre = pre
+        self.nxt = nxt
+        self.time = time
+
+
+def judge_time(entryTime, expire_date):
+    d = time.time() - entryTime
+    return d > expire_date
+
+
+def hash_key(funcName, args, kwargs):
+    key = pickle.dumps((funcName, args, kwargs))
+    return hashlib.md5(key).hexdigest()
+
+
+class Cache:
+    def __init__(self, expire_date=3):
+        self.head = Node(None, None, None)
+        self.tail = Node(None, None, None, pre=self.head)
+        self.head.nxt = self.tail
+        self.expire_date = 3
+
+    def __call__(self, func):
+        @functools.wraps(func)
+        def wrap(*args, **kwargs):
+            key = hash_key(func.__name__, args, kwargs)  # 得到该状态的hash值来判断是否计算过
+
+            t = self.head.nxt
+            while t is not self.tail:  # 判断并输出
+                if t.key == key:
+                    if not judge_time(t.time, self.expire_date):  # 如果在链表中，即把该节点放在最前面
+                        print('Hey! You have just calculated it!', end=' --> ')
+                        t.nxt.pre = t.pre
+                        t.pre.nxt = t.nxt
+                        self.head.nxt.pre = t
+                        t.nxt = self.head.nxt
+                        self.head.nxt = t
+                        t.pre = self.head
+                        return t.value
+                    else:  # 超时了就把它置为没有指针指向它的节点，等python自动回收空间
+                        t.pre.nxt = t.nxt
+                        t.nxt.pre = t.pre
+                        break
+                else:
+                    t = t.nxt
+
+            result = func(*args, **kwargs)
+            newNode = Node(key, result, time.time(), self.head, self.head.nxt)
+            self.head.nxt = newNode
+            newNode.nxt.pre = newNode
+            return result
+
+        return wrap
+
+@Cache()
+def add(x, y):
+    time.sleep(2)
+    return x+y
+
+print(add(1,2))
+
+print(add(1,2))
+
+print(add(1,3))
+
+print(add(1,3))

Diff for: Homework/mona/lz_episode_05/LRU.py

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+import base64
+import math
+
+b64 = {
+    'A':0,'B':1,'C':2,'D':3,'E':4,'F':5,'G':6,'H':7,'I':8,'J':9,'K':10,'L':11,'M':12,'N':13,
+    'O':14,'P':15,'Q':16,'R':17,'S':18,'T':19,'U':20,'V':21,'W':22,'X':23,'Y':24,'Z':25,'a':26,'b':27,
+    'c':28,'d':29,'e':30,'f':31,'g':32,'h':33,'i':34,'j':35,'k':36,'l':37,'m':38,'n':39,'o':40,'p':41,
+    'q':42,'r':43,'s':44,'t':45,'u':46,'v':47,'w':48,'x':49,'y':50,'z':51,'0':52,'1':53,'2':54,'3':55,
+    '4':56,'5':57,'6':58,'7':59,'8':60,'9':61,'+':62,'/':63
+}
+
+b = []  # 存放解码后的二进制数
+
+
+def transform(num):
+    l = [5, 4, 3, 2, 1, 0]
+    for x in range(6):
+        if num >= pow(2, l[x]):
+            b.append(1)
+            num -= pow(2, l[x])
+        else:
+            b.append(0)
+
+
+def printChar(lst):
+    l = [7, 6, 5, 4, 3, 2, 1, 0]
+    num_Ascall = 0
+    for x in range(8):
+        if lst[x] == 1:
+            num_Ascall += pow(2, l[x])
+
+    ch = chr(num_Ascall)
+    print(ch, end='')
+
+ori_s = 'Man'
+print('The original string is:{}'.format(ori_s))
+encodestr = base64.b64encode(ori_s.encode())
+print('The base64 string is:{}'.format(encodestr))
+s = encodestr.decode()
+
+for i in range(len(s)):
+    num = 0
+    if s[i] is not '=':
+        num = b64[s[i]]
+    transform(num)
+
+lst = []  # 存放八位二进制
+lst.append(b[0])
+print('The result of the decoding is:',end = '')
+
+for x in range(1, len(b)):  # 每8位输出一个字符
+    if x % 8 == 0:
+        printChar(lst)
+        lst.clear()
+    lst.append(b[x])
+
+printChar(lst)