'''

列表

'''

# list.count(x): 返回x在列表中出现的次数

a1 = [1,123.25,333,333,456.5]

print(a1.count(333),a1.count(123.25),a1.count(4))

# list.inster(i,x): 在索引号为i的元素前插入元素x

a2 =[2,123.25,333,333,456.5]

a2.insert(2,-1)

print('a2:',a2)  #

#a.insert(len(a),x):在列表的末尾添加x

a3 =[3,123.25,333,333,456.5]

a3.insert(len(a3),222)

print('a3:',a3)  #

#a.append(x):在列表末尾添加x

a4 =[3,123.25,333,333,456.5]

a4.append(222)

print('a4:',a4)

#a.index(x):返回值为x的索引号

a5 =[3,123.25,333,333,456.5]

print('a5:',a5.index(3))

#a.remove(x):移除列表中的元素x

a6 =[3,123.25,333,333,456.5]

a6.remove(3)

print('a6:',a6)

#a.reverse():列表中的元素倒排序

a7 =[3,123.25,333,333,456.5]

a7.reverse()

print('a7:',a7)

#对列表中的元素进行排序

a8 =[3,123.25,333,333,456.5]

a8.sort()

print('a8:',a8)

#list.pop():从列表中移除最后一个元素

a9 =[3,123.25,333,333,456.5]

a9.pop()

print('a9:',a9)

#list.pop(i):从列表中移除索引为i的元素

a10 =[3,123.25,333,333,456.5]

a10.pop(1)

print('a10:',a10)

'''

将列表当做对堆栈使用

'''

#后进先出

stack = [1,2,3,4,5,6]

stack.append(7)

print(stack)

stack.append(8)

print(stack)

stack.pop()

print(stack)

stack.pop()

print(stack)

'''

将列表当作队列使用

'''

from collections import deque

queue = deque(['google','runoob','taobao'])

print('1:',queue)

queue.append('baidu')

queue.append('tianmao')

print('',queue)

print(queue.popleft()) #从左边开始弹出，弹出后其他一个一个往前移动

print(queue.popleft())

print('3:',queue)

'''

列表推导式

'''

#将列表的值都乘以3后输出

vec1 = [2,4,6]

vec12 = [3*x for x in vec1]

print('1:',vec12)

#按要求生成子列表

vec2 = [2,4,6]

vec21 = [[x,x**2] for x in vec2]

print('2:',vec21)

#对列表中对每个元素调用某方法

freshfruit = ['apple','banan','orange']

freshfruit1 = [weapon.strip() for weapon in freshfruit]

print('freshfruit1:',freshfruit1)

#使用ifz作为过滤器

vec3 = [2,4,6]

vec31 = [3*x for x in vec3 if x >3]

print('vec31:',vec31)

vec32 = [3*x for x in vec3 if x <5]

print('vec32:',vec32)

#其他一些技巧演示

vec4 = [1,2,3]

vec5 = [4,5,-6]

vec451 = [x*y for x in vec4 for y in vec5]

print('vec451',vec451)

vec452 = [x+y for x in vec4 for y in vec5]

print('vec452:',vec452)

pass

pass

'''

嵌套列表解析

'''

pass

#del list[]:通过索引删除列表中的某个元素

d1 = [1,2,3,4,5,6,7]

del d1[0]

print('d1:',d1)

#删除对元素个数4-2=2个，从开始对索引开始删除

d2 = [0,1,2,3,4,5,6,7]

del d2[2:4]

print('d2:',d2)

#del list[:]:删除列表中对所有元素

d3 = [0,1,2,3,4,5,6,7]

del d3[:]

print('d3:',d3)

#del d:删除一个实体变量

# d4 = [0,1,2,3,4,5,6,7]

# del d4

# print('d4:',d4)

'''

元组和序列

'''

#元组对输出总是有圆括号对，输入可以有可以没有

t = (123,456,'hello')

print(t[0])

print('t：',t)

u = (t,(78,89,90))

print(u)

#元组输入时可以没有圆括号

t1 = 1,2,3

print('t1',t1)

'''

集合

'''

basket = {'apple','banana','orange','pear','apple','banana'}

#字典的基本功能：消除重复元素

print(basket)

#字典的基本功能：关系测试

print('apple' in basket)

print('runoob' in basket)

#set():创建集合

a = set('abcdeabc')

b = set('cdefghrr')

#集合去重操作

print(a)

#在a中但不在b中的

print(a-b)

#不同时在a或者b中

print(a^b)

#a和b的并集

print(a|b)

#a和b的交集

print(a&b)

#集合也支持推导式

c = {x for x in a if x not in b}

print(c)

'''

字典

'''

#使用{}创建字典

tel = {'jack01':6001,'jack02':6002,'jack03':6003}

#向字典中添加元素

tel1 = {'jack01':6001,'jack02':6002,'jack03':6003}

tel1['jack04'] = 6004

print('tel1：',tel1)

#del dict[键]：通过键值删除字典中的某个元素

tel2 = {'jack01':6001,'jack02':6002,'jack03':6003}

del tel2['jack01']

print('tel2:',tel2)

#打印出字典的键值列表

tel3 = {'jack01':6001,'jack02':6002,'jack03':6003}

print('tel3:',list(tel3.keys()))

#打印出字典的键值列表并排序

tel4 = {'jack01':6001,'ajack02':6002,'bjack03':6003}

print('tel4:',sorted(tel4.keys()))

#关系测试

tel5 = {'jack01':6001,'ajack02':6002,'bjack03':6003}

print('tel51:','jack01' in tel5)

print('tel52：','jack02' in tel5)

#构造函数dict()直接从键值队元=组列表中构建字典

tel6 = dict([('jack01',7001),('jack2',7002),('jack3',7003)])

print(tel6)

#字典推导

dict1 = {x:x**2 for x in (2,4,6) }

print(dict1)

#如果关键字只是简单对字符串，使用关键字参数指定键值对有时更方便

dict2 = dict(jack01=2001,jack02=2002,jack03=2003)

print(dict2)

'''

遍历技巧

'''

#字典中遍历时，关键字和对值可以使用item（）遍历出来

knights = {'jack01':'good','jack02':'better','jack03':'best'}

for k,v in knights.items():

    print(k,v)

#在遍历列表时，索引值和对应值可以使用enumerate()函数同时得到

for k,v in enumerate(['jack01','jack02','jack03']):

    print(k,v)

#zip()# 遍历两个或更多序列

questions=['name','age','class']

answers=['jack',18,'class1']

for q,a in zip(questions,answers):

    print("'what's your{0}? It is {1}".format(q,a))

#反向遍历一个序列用reversed()

for i in reversed(range(1,10,2)):

    print('反向遍历：',i)

#sorted()按顺序遍历

str1 = ['a','b','d','e']

for i in sorted(str1):

    print('sorted():',i)