1，昨日内容及作业讲解
ascii：字母，数字，特殊字符：1个字节，8位
Unicode：16位 两个字节 升级 32 位 四个字节
utf-8：最少一个字节 8位表示。 英文字母 8位 1个字节
欧洲16位，2个字节
中文24位，3个字节
gbk：中文2个字节，英文字母1个字节。
int：bit_lenth()
bool:True False
str: str --->bool :bool(str): ''--->False
str:
s = 'alexsb'
s1 = s[1]
s2 = s[1:3]
s3 = s[0:] s[:]
s4 = s[0:-1]
s5 = s[0:3:2]
s6 = s[2::-2]
captlze首字母大写
upper()全大写
lower()全小写
find通过元素找索引，找不到-1
index()通过元素找索引，找不到 报错
swpcase 大小写翻转
repalce(old,new,count)
isdigit() 返回bool值
isapha()
isnumpha()
startswith endswith
title 首字母大写
center（）居中
strip（）lstrip rstrip
split
format 格式化输出
{}
{0}{1}{2}{0}
{name}{age}{hobby} name= age+ hobby
len() 长度
count 计数
for i in 可迭代对象：
pass
2，列表
增删改查
列表的循环
列表的嵌套
#元祖 只读列表，可循环查询，可切片。 #儿子不能改，孙子可能可以改。 # tu = (1,2,3,'alex',[2,3,4,'taibai'],'egon') # # print(tu[3]) # # print(tu[0:4]) # # for i in tu: # # print(i) # tu[4][3]=tu[4][3].upper() # print(tu) # tu[4].append('sb') # print(tu) # s = 'alex' # s1 = 'sb'.join(s) # print(s1) #列表转化成字符串 list -----> str join # li = ['taibai','alex','wusir','egon','女神',] # s = '++++'.join(li) #str ----->list split() # print(s) #range [1,2,3,4,5,6,.......100........] # for i in range(3,10): # print(i) # for i in range(10): # print(i) # for i in range(0,10,3): # print(i) # for i in range(10,0,-2): # print(i) # for i in range(10,-1,-2): # print(i) li = [1,2,3,5,'alex',[2,3,4,5,'taibai'],'afds'] # for i in li: # if type(i) == list: # for k in i: # print(k) # else:print(i) for i in range(len(li)): if type(li[i]) == list: for j in li[i]: print(j) else:print(li[i])
# s = '132a4b5c' # s1 = s[0]+s[2]+s[1] # print(s1) #使用while和for循环分别打印字符串s=’asdfer’中每个元素。 s = 'fkld' # for i in s: # print(i) # index = 0 # while 1: # print(s[index]) # index += 1 # if index == len(s):break #如：content = input(‘请输入内容:’) # 如用户输入：5+9或5+ 9或5 + 9，然后进行分割再进行计算。 # content=input('>>>').strip() # con1=content.split('+') #li[] # num=0 # for i in con1: # num+=int(i) # print(num) # content=input('>>>').strip() # index = content.find("+") # a = int(content[0:index]) # b = int(content[index+1:]) # print(a + b) #咱们任意输入一串文字+数字 统计出来数字的个数 s = input("请输入：") # '1234324324fdsaf1fdsaf12' count = 0 for i in s: if i.isdigit(): count += 1 print(count)
3，元祖
# li = ['alex',[1,2,3],'wusir','egon','女神','taibai'] # l1 = li[0] # print(l1) # l2 = li[1] # print(l2) # l3 = li[0:3] # print(l3) li = ['alex','wusir','egon','女神','taibai'] #增加 append insert # li.append('日天') # li.append(1) # print(li) # while 1: # username = input('>>>') # if username.strip().upper() == 'Q': # break # else: # li.append(username) # print(li) # li.insert(4,'春哥') # print(li) # li.extend('二哥') # li.extend([1,2,3]) # print(li) #删 li = ['taibai','alex','wusir','egon','女神',] # name = li.pop(1) # 有返回值 # name = li.pop() # 默认删除最后一个 # print(name,li) # li.remove('taibai') # 按元素去删除 # print(li) # li.clear() # 清空 # print(li) # del li #删除列表li # del li[0:2] # 切片去删除 # print(li) #改 # li[0] = '男兽' # li[0] = [1,2,3] #切片改 # li[0:3] = '云姐plfdslkmgdfjglk' # li[0:3] = [1,2,3,'春哥','咸鱼哥'] # print(li) #查 # for i in li: # print(i) # print(li[0:2]) #公共方法： # l = len(li) # print(l) # num = li.count('taibai') # print(num) # print(li.index('wusir')) # li = [1,5,4,7,6,2,3] # #正向排序 # # li.sort() # # print(li) # #反向排序 # # li.sort(reverse=True) # # print(li) # #反转 # li.reverse() # print(li) #列表的嵌套 li = ['taibai','武藤兰','苑昊',['alex','egon',89],23] # print(li[1][1]) # name = li[0].capitalize() # # print(name) # li[0] = name # li[0] = li[0].capitalize() # li[2] = '苑日天' # print(li[2].replace('昊','ritian')) # li[2] = li[2].replace('昊','ritian') # li[3][0] = li[3][0].upper() # print(li) li=[1,2,3] s = str(li) print (s,type(s))