第三节 python 列表、元组、字典

第三节 python 列表、元组、字典

***************************************************************************************************2018-10-06 day12-01


上节内容回顾和补充

编程语言
高级
低级

Python种类
JavaPython
cPython *****
pypy

字节码 和 机器码

Python程序:
1.
终端:
C:\python35\python.exe D:\1.py
解释器:
C:\python35\python.exe

2. 文件形
#/usr/bin/u/ubv/a python

python 1.py

./1.py 加权限

3. 编码
#/usr/bin/u/ubv/a python
# -*- coding:utf-8 -*-
补充:

字节,位
unicode utf8 gbk
utf8: 3
gbk : 2

4. print("sdf")

5. inp = input('>>>')

PS:
>>> hello
inp = "hello"


>>> 10
inp = "10"

# 如果将字符串转换成数字 new_inp = int(inp)

inp * 10 =?????


6. 变量名

字母
数字
下划线

要求:
不能数字开头
不能使用关键字
建议不要用python内置的。。。。

7. 条件语句
1. 基本
2. 嵌套
3. if elif else ...

8. while循环
while 条件:
....

print('...')

补充:
a. while else
b. continue break
continue ,终止当前循环,开始下一次循环
break ,终止所有循环

用户登陆(三次机会重试)
count = 0
while count < 3:
user = input('>>>')
pwd = input('>>>')
if user == 'alex' and pwd == '123':
print('欢迎登陆')
print('..........')
break
else:
print('用户名或者密码错误')
count = count + 1

今日内容:

python开发IDE: pycharm、eclipse

# 专业版
# 不要汉化

1、运算符
结果是值
算数运算
a = 10 * 10
赋值运算
a = a + 1 a+=1

结果是布尔值
比较运算
a = 1 > 5
逻辑运算
a = 1>6 or 1==1
成员运算
a = "蚊" in "郑建文"

2、基本数据类型


数字 int ,所有的功能,都放在int里
a1 = 123
a1 = 456

- int
将字符串转换为数字
a = "123"
print(type(a),a)

b = int(a)
print(type(b),b)

num = "0011"
v = int(num, base=16)
print(v)
- bit_lenght
# 当前数字的二进制,至少用n位表示
r = age.bit_length()

字符串 str
###########################################

# 1 首字母大写
# test = "aLex"
# v = test.capitalize()
# print(v)

# 2 所有变小写,casefold更牛逼,很多未知的对相应变小写
# v1 = test.casefold()
# print(v1)
# v2 = test.lower()
# print(v2)

# 3 设置宽度,并将内容居中
# 20 代指总长度
# * 空白未知填充,一个字符,可有可无
# v = test.center(20,"中")
# print(v)

# test = "alex"
# v = test.ljust(20,"*")
# print(v)

# test = "alex"
# v = test.rjust(20,"*")
# print(v)

# test = "alex"
# v = test.zfill(20)
# print(v)


# 4 去字符串中寻找,寻找子序列的出现次数
# test = "aLexalexr"
# v = test.count('ex')
# print(v)

# test = "aLexalexr"
# v = test.count('ex',5,6)
# print(v)

# 欠
# encode
# decode

# 5
# 以什么什么结尾
# 以什么什么开始
# test = "alex"
# v = test.endswith('ex')
# v = test.startswith('ex')
# print(v)

# 6 expandtabs,断句20,
# test = "username\temail\tpassword\nlaiying\[email protected]\t123\nlaiying\[email protected]\t123\nlaiying\[email protected]\t123"
# v = test.expandtabs(20)
# print(v)

# 7 从开始往后找,找到第一个之后,获取其未知
# > 或 >=
# test = "alexalex"
# 未找到 -1
# v = test.find('ex')
# print(v)

# 8 index找不到,报错 忽略
# test = "alexalex"
# v = test.index('8')
# print(v)


# 9 格式化,将一个字符串中的占位符替换为指定的值
# test = 'i am {name}, age {a}'
# print(test)
# v = test.format(name='alex',a=19)
# print(v)

# test = 'i am {0}, age {1}'
# print(test)
# v = test.format('alex',19)
# print(v)

# 10 格式化,传入的值 {"name": 'alex', "a": 19}
# test = 'i am {name}, age {a}'
# v1 = test.format(name='df',a=10)
# v2 = test.format_map({"name": 'alex', "a": 19})

# 11 字符串中是否只包含 字母和数字
# test = "123"
# v = test.isalnum()
# print(v)
# str

# 12 是否是字母,汉子
# test = "as2df"
# v = test.isalpha()
# print(v)

# 13 当前输入是否是数字
# test = "二" # 1,②
# v1 = test.isdecimal()
# v2 = test.isdigit()
# v3 = test.isnumeric()
# print(v1,v2,v3)


# 14 是否存在不可显示的字符
# \t 制表符
# \n 换行
# test = "oiuas\tdfkj"
# v = test.isprintable()
# print(v)

# 15 判断是否全部是空格
# test = ""
# v = test.isspace()
# print(v)

# 16 判断是否是标题
# test = "Return True if all cased characters in S are uppercase and there is"
# v1 = test.istitle()
# print(v1)
# v2 = test.title()
# print(v2)
# v3 = v2.istitle()
# print(v3)

# 17 ***** 将字符串中的每一个元素按照指定分隔符进行拼接
# test = "你是风儿我是沙"
# print(test)
# # t = ' '
# v = "_".join(test)
# print(v)

# 18 判断是否全部是大小写 和 转换为大小写
# test = "Alex"
# v1 = test.islower()
# v2 = test.lower()
# print(v1, v2)

# v1 = test.isupper()
# v2 = test.upper()
# print(v1,v2)
# 19
# 移除指定字符串
# 有限最多匹配
# test = "xa"
# # v = test.lstrip('xa')
# v = test.rstrip('9lexxexa')
# # v = test.strip('xa')
# print(v)

# test.lstrip()
# test.rstrip()
# test.strip()
# 去除左右空白
# v = test.lstrip()
# v = test.rstrip()
# v = test.strip()
# print(v)
# print(test)
# 去除\t \n
# v = test.lstrip()
# v = test.rstrip()
# v = test.strip()
# print(v)

# 20 对应关系替换
# test = "aeiou"
# test1 = "12345"

# v = "asidufkasd;fiuadkf;adfkjalsdjf"
# m = str.maketrans("aeiou", "12345")
# new_v = v.translate(m)
# print(new_v)

# 21 分割为三部分
# test = "testasdsddfg"
# v = test.partition('s')
# print(v)
# v = test.rpartition('s')
# print(v)

# 22 分割为指定个数
# v = test.split('s',2)
# print(v)
# test.rsplit()


# 23 分割,只能根据,true,false:是否保留换行
# test = "asdfadfasdf\nasdfasdf\nadfasdf"
# v = test.splitlines(False)
# print(v)

# 24 以xxx开头,以xx结尾
# test = "backend 1.1.1.1"
# v = test.startswith('a')
# print(v)
# test.endswith('a)

# 25 大小写转换
# test = "aLex"
# v = test.swapcase()
# print(v)

# 26 字母,数字,下划线 : 标识符 def class
# a = "def"
# v = a.isidentifier()
# print(v)


# 27 将指定字符串替换为指定字符串
# test = "alexalexalex"
# v = test.replace("ex",'bbb')
# print(v)
# v = test.replace("ex",'bbb',2)
# print(v)
###################### 7个基本魔法 ######################
# join # '_'.join("asdfasdf")
# split
# find
# strip
# upper
# lower
# replace
###################### 4个灰魔法 ######################
# test = "郑建文妹子有种冲我来"

# 一、for循环
# for 变量名 in 字符串:
# 变量名
# break
# continue


# index = 0
# while index < len(test):
# v = test[index]
# print(v)
#
# index += 1
# print('=======')

# for zjw in test:
# print(zjw)

# test = "郑建文妹子有种冲我来"
# for item in test:
# print(item)
# break

# for item in test:
# continue
# print(item)

# 二、索引,下标,获取字符串中的某一个字符
# v = test[3]
# print(v)

# 三、切片
# v = test[0:-1] # 0=< <1
# print(v)

# 四、获取长度
# Python3: len获取当前字符串中由几个字符组成
# v = len(test)
# print(v)

# 注意:
# len("asdf")
# for循环
# 索引
# 切片

# 五、获取连续或不连续的数字,
# Python2中直接创建在内容中
# python3中只有for循环时,才一个一个创建
# r1 = range(10)
# r2 = range(1,10)
# r3 = range(1,10,2)
# 帮助创建连续的数字,通过设置步长来指定不连续
# v = range(0, 100, 5)
#
# for item in v:
# print(item)

##### 练习题:根据用户输入的值,输出每一个字符以及当前字符所在的索引位置 #####
# test = input(">>>")
# for item in test:
# print(item)

# 将文字 对应的索引打印出来:
# test = input(">>>")
# print(test) # test = qwe test[0] test[1]
# l = len(test) # l = 3
# print(l)
#
# r = range(0,l) # 0,3
# for item in r:
# print(item, test[item]) # 0 q,1 w,2 e

# test = input(">>>")
# for item in range(0, len(test)):
# print(item, test[item])


###################### 1个深灰魔法 ######################
# 字符串一旦创建,不可修改
# 一旦修改或者拼接,都会造成重新生成字符串

# name = "zhengjianwen"
# age = "18"
#
# info = name + age
# print(info)


列表 list
...
元祖 tuple
...
字典 dict
...

布尔值 bool
...

----> 列表,元祖,字典,布尔值 详细操作见课上代码

布尔值运算:

#“” =》假

#“ ”=》真

#0=》假

#其他=》真

21、是否是可迭代对象?

     for i in 值:

         print(i)

可迭代对像 ==可以被for进行循还获取

str

      各种方法

....

a1="alex"

a2="alex"

int 

   ...

a=123

v="_".join(['alex','eric'])

'alex_eric'

从小到大,for i in range(0,100,1)

                   print(i)

从大到小,for i in range(0,100,-1)

                   print(i)

input:字符串“5+9”

value="5+9"

v1,v2=value.split("+")

v1=int(v1)

v2=int(v2)

v1+v2

c1 = 0

c2 = 0

val = input('>>>')

for item in val:

#如果item是数字:

c1+=1

#如果item是字母:

C2+=2

格式不一,菜单栏code reform ----》》code

***************************************************************************************************2018-10-06 day12-02

列表list

li=[1,12,9,'age','alex',【‘石振文’,【‘19’,10】,‘庞麦朗’】]

中括号括起来

分割每个元素

列表中的元素可以是数字,字符串

还可以嵌套列表,布尔值》。。所有的都能放进去

集合,内部放置任何东西

#索引取值

print(li[3])

print(li[3:-1])

切片,切片结果也是列表

for 循环

while循环

for item in li:

    print(item)

都可以用break and continue

链表

列表元素,可以被修改

li=[1,12,9,True]

li[1]=120 li[1:3]=[120,90]

print(li)

列表元素,可以被删除

del li[1] del li[2:6]

print(li)

in 操作

v=120 in li

li=[1,12,9,'age','alex',【‘石振文’,【‘19’,10】,‘庞麦朗’】]

操作

li=[1,12,9,'age','alex',【‘石振文’,【‘19’,10】,‘庞麦朗’】]

li[4][1][0][1]字符串也可以索引

s='lkkjljlkljlkjljljljlkj' 可以进行循环

a='123'

int(a)

a=123

str(a)

new_li=list(s)

print(new_li)

对于字符串转换列表,list(字符串)在内部使用了For 循玩

对于数字确不能

li=[11,22,33,'123','alex'']

r=str(li)

print(r)

for i in li:

 s = s+str(i) 并不是所有的分片 都是字符串,分出来后11 22 33 是数字

列表转换成字符串

需要自己写for 循环一个一个处理:既有数字又有字符串

li=['123','alex']

v='',join(li)

print(v) 

可以拼接

li=[123,'alex']

v='',join(li)

print(v) 

不能拼接

li =[11,22,33,44]

v=li.append(5) None 什么都不是

print(v)

li=[11,22,33,44,5,22]

li.clear()

浅拷呗

v=li.copy()

v=li.copy()

print(v)

4.计算元素出现的次数

v=li.count()

print(v)

#!/usr/bin/env python
# -*- coding:utf-8 -*-

# v = "李杰"
# for item in v:
# print(item)
####################################################################################################
# str
# name = "alex"

# list # 类,列表
# li = [1, 12, 9, "age", ["石振文", ["19", 10], "庞麦郎"], "alex", True] # 通过list类创建的对象,li
# list 类
# list类的一个对象


#######################################灰魔法: list类中提供的方法 #######################################

# li = [11, 22, 33, 22, 44]
# 参数
# 1. 原来值最后追加
# 对象.方法(..) # li对象调用append方法
# li.append(5)
# li.append("alex")
# li.append([1234,2323])
# print(li)
# 2 清空列表
# li.clear()
# print(li)

# 3 拷贝,浅拷贝
# v = li.copy()
# print(v)
# 4. 计算元素出现的次数
# v = li.count(22)
# print(v)

# 5. 扩展原列表,参数:可迭代对象
# li = [11, 22, 33, 22, 44]
# li.append([9898,"不得了"])
# [11, 22, 33, 22, 44, [9898, '不得了']]

# li.extend([9898,"不得了"])
# for i in [9898,"不得了"]:
# li.append(i)
# [11, 22, 33, 22, 44, 9898, '不得了']
#
# li.extend("不得了")
# print(li)

# 6. 根据值获取当前值索引位置(左边优先)
# li = [11, 22, 33, 22, 44]
# v= li.index(22)
# print(v)

# 7. 在指定索引位置插入元素
# li = [11, 22, 33, 22, 44]
# li.insert(0,99)
# print(li)

# 8、 删除某个值(1.指定索引;2. 默认最后一个),并获取删除的值
# li = [11, 22, 33, 22, 44]
# v = li.pop()
# print(li)
# print(v)

# li = [11, 22, 33, 22, 44]
# v = li.pop(1)
# print(li)
# print(v)
# 9. 删除列表中的指定值,左边优先
# li = [11, 22, 33, 22, 44]
# li.remove(22)
# print(li)
# PS: pop remove del li[0] del li[7:9] clear

# 10 将当前列表进行翻转
# li = [11, 22, 33, 22, 44]
# li.reverse()
# print(li)

# 11 列表的排序
# li = [11,44, 22, 33, 22]
# li.sort()
# li.sort(reverse=True)
# print(li)
### 欠
# cmp
# key
# sorted

####################################### 深灰魔法 #######################################
# 1. 列表格式
# 2. 列表中可以嵌套任何类型
# 中括号括起来
# ,分割每个元素
# 列表中的元素可以是 数字,字符串,列表,布尔值..所有的都能放进去
# “集合”,内部放置任何东西
"""
# 3.
# 索引取值
print(li[3])
# 4 切片,切片结果也是列表
print(li[3:-1])

# 5 for循环
# while循环
for item in li:
print(item)
"""
# 列表元素,可以被修改

# li = [1, 12, 9, "age", ["石振文", ["19", 10], "庞麦郎"], "alex", True]

############## 6 索引
# 修改
# li[1] = 120
# print(li)
# li[1] = [11,22,33,44]
# print(li)

# 删除,第一种方式
# del li[1]
# print(li)
############## 7 切片
# 修改
# li[1:3] = [120,90]
# print(li)
# 删除
# del li[2:6]
# print(li)

# 8 in 操作
# li = [1, 12, 9, "age", ["石振文", ["19", 10], "庞麦郎"], "alex", True]
# v1 = "石振文" in li
# print(v1)
# v2 = "age" in li
# print(v2)
###### 列表中的元素,

# 9 操作
# li = [1, 12, 9, "age", ["石振文", ["19", 10], "庞麦郎"], "alex", True]
# li[4][1][0]
# [1]

# li = [1, 12, 9, "age", ["石振文", ["19", 10], "庞麦郎"], "alex", True]

# s = "pouaskdfauspdfiajsdkfj"
# s = 123
# a = "123"
# int(a)
# a = 123
# str(a)
# 10 转换
# 字符串转换列表 li = list("asdfasdfasdf"), 内部使用for循环
# s = "pouaskdfauspdfiajsdkfj"
# new_li = list(s)
# print(new_li)

# 列表转换成字符串,
# 需要自己写for循环一个一个处理: 既有数字又有字符串
# li = [11,22,33,"123","alex"]
# # r = str(li) # '[11,22,33,"123","alex"]'
# # print(r)
# s = ""
# for i in li:
# s = s + str(i)
# print(s)
# 直接使用字符串join方法:列表中的元素只有字符串
# li = ["123","alex"]
# v = "".join(li)
# print(v)

### 补充:字符串创建后,不可修改
# v = "alex"
# v = v.replace('l','el')
# print(v)

# li = [11,22,33,44]
# li[0]
# li[0] = 999

# s = "alex"
# li[0]
# s[0] = "E"

# li = [11,22,33,44]
# print(li)
# print(li)
# print(li)
# print(li)
# print(li)
# print(li)
# print(li)
# print(li)
# 列表,有序;元素可以被修改

# 列表
# list
# li = [111,22,33,44]


####################################################################################################

# 元组,元素不可被修改,不能被增加或者删除
# tuple
# tu = (11,22,33,44)
# tu.count(22),获取指定元素在元组中出现的次数
# tu.index(22)

####################################### 深灰魔法 #######################################
# 1. 书写格式
# tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
# 一般写元组的时候,推荐在最后加入 ,
# 元素不可被修改,不能被增加或者删除
# 2. 索引
# v = tu[0]
# print(v)

# 3. 切片
# v = tu[0:2]
# print(v)

# 4. 可以被for循环,可迭代对象
# for item in tu:
# print(item)

# 5. 转换
# s = "asdfasdf0"
# li = ["asdf","asdfasdf"]
# tu = ("asdf","asdf")
#
# v = tuple(s)
# print(v)

# v = tuple(li)
# print(v)

# v = list(tu)
# print(v)

# v = "_".join(tu)
# print(v)

# li = ["asdf","asdfasdf"]
# li.extend((11,22,33,))
# print(li)

# 6.元组的一级元素不可修改/删除/增加
# tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
# # 元组,有序。
# # v = tu[3][0][0]
# # print(v)
# # v=tu[3]
# # print(v)
# tu[3][0] = 567
# print(tu)

####################################################################################################
# 字典
# dict
# dict
# dic = {
# "k1": 'v1',
# "k2": 'v2'
# }
# 1 根据序列,创建字典,并指定统一的值
# v = dict.fromkeys(["k1",123,"999"],123)
# print(v)

# 2 根据Key获取值,key不存在时,可以指定默认值(None)
# v = dic['k11111']
# print(v)
# v = dic.get('k1',111111)
# print(v)

# 3 删除并获取值
# dic = {
# "k1": 'v1',
# "k2": 'v2'
# }
# v = dic.pop('k1',90)
# print(dic,v)
# k,v = dic.popitem()
# print(dic,k,v)

# 4 设置值,
# 已存在,不设置,获取当前key对应的值
# 不存在,设置,获取当前key对应的值
# dic = {
# "k1": 'v1',
# "k2": 'v2'
# }
# v = dic.setdefault('k1111','123')
# print(dic,v)

# 5 更新
# dic = {
# "k1": 'v1',
# "k2": 'v2'
# }
# dic.update({'k1': '111111','k3': 123})
# print(dic)
# dic.update(k1=123,k3=345,k5="asdf")
# print(dic)

# 6 keys() 7 values() 8 items() get update
##########

# 1、基本机构
# info = {
# "k1": "v1", # 键值对
# "k2": "v2"
# }
#### 2 字典的value可以是任何值
# info = {
# "k1": 18,
# "k2": True,
# "k3": [
# 11,
# [],
# (),
# 22,
# 33,
# {
# 'kk1': 'vv1',
# 'kk2': 'vv2',
# 'kk3': (11,22),
# }
# ],
# "k4": (11,22,33,44)
# }
# print(info)

#### 3 布尔值(1,0)、列表、字典不能作为字典的key
# info ={
# 1: 'asdf',
# "k1": 'asdf',
# True: "123",
# # [11,22]: 123
# (11,22): 123,
# # {'k1':'v1'}: 123
#
# }
# print(info)

# 4 字典无序

# info = {
# "k1": 18,
# "k2": True,
# "k3": [
# 11,
# [],
# (),
# 22,
# 33,
# {
# 'kk1': 'vv1',
# 'kk2': 'vv2',
# 'kk3': (11,22),
# }
# ],
# "k4": (11,22,33,44)
# }
# print(info)

# 5、索引方式找到指定元素
# info = {
# "k1": 18,
# 2: True,
# "k3": [
# 11,
# [],
# (),
# 22,
# 33,
# {
# 'kk1': 'vv1',
# 'kk2': 'vv2',
# 'kk3': (11,22),
# }
# ],
# "k4": (11,22,33,44)
# }
# # v = info['k1']
# # print(v)
# # v = info[2]
# # print(v)
# v = info['k3'][5]['kk3'][0]
# print(v)

# 6 字典支持 del 删除
# info = {
# "k1": 18,
# 2: True,
# "k3": [
# 11,
# [],
# (),
# 22,
# 33,
# {
# 'kk1': 'vv1',
# 'kk2': 'vv2',
# 'kk3': (11,22),
# }
# ],
# "k4": (11,22,33,44)
# }
# del info['k1']
#
# del info['k3'][5]['kk1']
# print(info)

# 7 for循环
# dict
# info = {
# "k1": 18,
# 2: True,
# "k3": [
# 11,
# [],
# (),
# 22,
# 33,
# {
# 'kk1': 'vv1',
# 'kk2': 'vv2',
# 'kk3': (11,22),
# }
# ],
# "k4": (11,22,33,44)
# }
# for item in info:
# print(item)
#
# for item in info.keys():
# print(item)

# for item in info.values():
# print(item)

# for item in info.keys():
# print(item,info[item])

# for k,v in info.items():
# print(k,v)

# True 1 False 0
# info ={
# "k1": 'asdf',
# True: "123",
# # [11,22]: 123
# (11,22): 123,
# # {'k1':' v1'}: 123
#
# }
# print(info)

####################### 整理 #################

# 一、数字
# int(..)
# 二、字符串
# replace/find/join/strip/startswith/split/upper/lower/format
# tempalte = "i am {name}, age : {age}"
# # v = tempalte.format(name='alex',age=19)
# v = tempalte.format(**{"name": 'alex','age': 19})
# print(v)
# 三、列表
# append、extend、insert
# 索引、切片、循环
# 四、元组
# 忽略
# 索引、切片、循环 以及元素不能被修改
# 五、字典
# get/update/keys/values/items
# for,索引

# dic = {
# "k1": 'v1'
# }

# v = "k1" in dic
# print(v)

# v = "v1" in dic.values()
# print(v)
# 六、布尔值
# 0 1
# bool(...)
# None "" () [] {} 0 ==> False

***************************************************************************************************2018-10-06 day12-03

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转载自www.cnblogs.com/zhangjiancun/p/9747920.html