python
#1.算数运算符# a = 5
# b = 2
# print(a + b)# 7
# print(a - b)# 3
# print(a * b)# 10
# print(a / b)# 2.5
# print(a % b)# 1 取模/取余
# print(a ** b) # 25取幂，a的b次方5的2次方25
# print(a // b) # 2 取整
# 2.赋值运算法
# a = 9
# b = 4
# a += b
# print(a)# 13
# a -= b
# print(a)# 5
# a *= b
# print(a)# 36
# a /= b
# print(a)# 2.25
# a // b
# print(a)# 9
# a %= b
# print(a)# 1
# 3.比较运算符
# a = 4
# b = 3
# c = 4
# print(a > b) True
# print(a < c) False
# print(a >= b) True
# print(a <= c) True
# print(a != b) True
# print(a == c) True
# 4.逻辑运算符and，or，not
# a = 7
# b = 5
# c = 7
# print(a > b and a >= c) True
# print(a >= c or a < b) True
# print(not a > c) True
# print(not a==c) False
# 5.成员运算符
# list1 = ["wangqian",320,"xiaohei","banli"]
# print("320" not in list1) True
# print(320 not in list1) False
# print("wangqian" in list1) True
# 成员运算符应用场景
# if "banli" in list1:
# print("测试成功")
# else:
# print("测试失败")
# 6.位运算符
# a = 7
# b = 12
'''
0 0 000000
128 64 3216 8421
00000111
00001100
'''
# print(a & b) # 400000100
# print(a | b) # 1500001111
# print(a ^ b) # 1100001011
# 公式：-（x+1）
# print(~ a) # -8
# print(~ b) # 13
# a = 7
'''
00000111
'''
# print(a << 2) # 2800011100
# print(a >> 2) # 1 00000001
# 7.索引
# str1 = "banlizi"
# print(str1) # b
# print(str1) # z
# print(str1) # 索引越界
# print(str1[-1])# i
# print(str1[-5])# n
# print(str1) #索引越界
# 8.切片
# str1 = "zhangguowei"
# print(str1) #zhang
# print(str1[:5]) #zhang
# print(str1) #hangguowei
# print(str1[:5:-1]) #iewou
# print(str1)#nahz
# print(str1[-6:-3]) #guo
# print(str1[-4:1:-1]) #ouggna
# print(str1[::]) #zhangguowei
# print(str1[::-1]) #iewouggnahz
# print(str1[-5:0]) #值为空
# 跳切
# str1 = "zhangguowei"
# print(str1) #hn
# print(str1[:6:2]) #zag
# 字符串
# str1 = "hello xiaohei"
# print(str1.capitalize()) #将首字母变成大写
# print(str1.title()) #单词开头是大写，其余是小写
# print(str1.count("i")) #2统计字符出现的次数
# print('_'.join(str1)) #h_e_l_l_o_ _x_i_a_o_h_e_i 连接字符的元素
# print('+'.join(str1)) #h+e+l+l+o+ +x+i+a+o+h+e+i
# print(str1.split("o")) #['hell', ' xia', 'hei']把字符串指定的标识符进行分割
# print(type(str1.split("o"))) #<class 'list'>返回上一个列表
# print(str1.split(" ")) #['hello', 'xiaohei']
# str1 = "banlizi"
# print(str1.strip("ba")) #nlizi删除字符串开头结尾的字符
# print(str1.strip("b")) #anlizi
# print(str1.strip("i")) #banliz
# print(str1.lstrip("ba")) #nlizi删除字符串开头ab的字符
# print(str1.rstrip("zi")) #banli删除字符串结尾的字符
# str1 = asdfghjkl #判断字符串是否以什么开始
# print(str1.startswith("as")) #True
# print(str1.startswith("s")) #False
# print(str1.startswith("a")) #True
# print(str1.endswith("kl")) #True
# print(str1.endswith("k")) #False
# file_name = input("请上传文件名称")
# if file_name.endswith(".txt"):
# print("输入文件有效")
# else:
# print("输入文件无效")
#查询
#str1 = "wangqian"
# print(str1.find("g")) #3
# print(str1.find("q")) #4
# print(str1.rfind("i")) #5
# print(str1.rfind("q")) #4
# str1 = "wangqian" new替换字符串
# print(str1.replace("wang","xiao")) #xiaoqian
# print(str1.replace("w","x")) #xangqian
# str1 = "zxcvbnm" 转换字符串中所有的字符为大写或小写
# print(str1.lower()) #zxcvbnm
# print(str1.upper()) #ZXCVBNM
# str1 = "ASDdfghg1234" 判断是否全部为数字
# print(str1.isdigit()) #False
# str1 = "ASDdfghg" 判断是否为全部为字母
# print(str1.isalpha()) #True
# str1 = "ASDdfghg1234$%" #判断是否全部为字母或数字或字母组合，有特殊字符返回false
# print(str1.isalnum()) #False
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