Python中顺序表的实现简单代码分享

#!/usr/bin/env python# -*- coding:utf-8 -*-class SeqList(object): def __init__(self, max=8):  self.max = max  #创建默认为8  self.num = 0  self.date = [None] * self.max  #list()会默认创建八个元素大小的列表，num=0，并有链接关系  #用list实现list有些荒谬，全当练习  #self.last = len(self.date)  #当列表满时，扩建的方式省略 def is_empty(self):  return self.num is 0 def is_full(self):  return self.num is self.max #获取某个位置的元素 def __getitem__(self, key):  if not isinstance(key, int):   raise TypeError  if 0<= key < self.num:   return self.date[key]  else:   #表为空或者索引超出范围都会引发索引错误   raise IndexError #设置某个位置的元素 def __setitem__(self, key, value):  if not isinstance(key, int):   raise TypeError  #只能访问列表里已有的元素,self.num=0时，一个都不能访问,self.num=1时，只能访问0  if 0<= key < self.num:   self.date[key] = value #该位置无元素会发生错误  else:   raise IndexError def clear(self):  self.__init__() def count(self):  return self.num def __len__(self):  return self.num #加入元素的方法 append()和insert() def append(self,value):  if self.is_full():   #等下扩建列表   print("list is full")   return  else:   self.date[self.num] = value   self.num += 1 def insert(self,key,value):  if not isinstance(key, int):   raise TypeError  if key<0: #暂时不考虑负数索引   raise IndexError  #当key大于元素个数时，默认尾部插入  if key>=self.num:   self.append(value)  else:   #移动key后的元素   for i in range(self.num, key, -1):    self.date[i] = self.date[i-1]   #赋值   self.date[key] = value   self.num += 1 #删除元素的操作 def pop(self,key=-1):  if not isinstance(key, int):   raise TypeError  if self.num-1 < 0:   raise IndexError("pop from empty list")  elif key == -1:   #原来的数还在，但列表不识别他   self.num -= 1  else:   for i in range(key,self.num-1):    self.date[i] = self.date[i+1]   self.num -= 1 def index(self,value,start=0):  for i in range(start, self.num):   if self.date[i] == value:    return i  #没找到  raise ValueError("%d is not in the list" % value) #列表反转 def reverse(self):  i,j = 0, self.num - 1  while i<j:   self.date[i], self.date[j] = self.date[j], self.date[i]   i,j = i+1, j-1if __name__=="__main__": a = SeqList() print(a.date) #num == 0 print(a.is_empty()) a.append(0) a.append(1) a.append(2) print(a.date) print(a.num) print(a.max) a.insert(1,6) print(a.date) a[1] = 5 print(a.date) print(a.count()) print("返回值为2(第一次出现)的索引：", a.index(2, 1)) print("====") t = 1 if t:  a.pop(1)  print(a.date)  print(a.num) else:  a.pop()  print(a.date)  print(a.num) print("========") print(len(a)) a.reverse() print(a.date) """ print(a.is_full()) a.clear() print(a.date) print(a.count()) """