python操作运算、
#python常见的运算符操作#1.算数运算符
a = 5
b = 3
#print(a+b) #8
#print(a-b) 2
#print(a*b)15
#print(a/b) 1.6666666666666667
#print(a%b) 2 取模/取余
#print(a**b) 125 a的b次方
#print(a//b)1 取商
#2.赋值运算符
a = 5
b = 3
#a += b8,
#a -= b 2
#a *= b 15
#a /= b1.6666666666666667
#a //= b1
#a %= b2
#print(a)
#3.比较运算符
a = 5
b = 3
c = 5
#print(a > b)true
#print(a > c) false
#print(a >= c) true
#print(a != c)false
#print(a == c) true
#4.逻辑运算符and or not
# a = 5
# b = 3
# c = 5
# print(a > b and a >= c)true
# # print(a > b or a < c )True
# # print(not a > c ) True
# #5.成员运算符
# list1 = ["天下","天上",520]
# # print(520 in list1)true
# # print("天下" not in list1)False
# if "天上" in list1:
# print("成功")
# else:
# print("失败")
#6.索引
# str1 = "duoceshi"
# print(str1) #用索引来访问序列中的元素，有正向和负向
# print(str1[-2])
# #7.切片
# str1 = "duoceshi"
# #print(str1) #uoce
# #print(str1) # uoceshi
# print(str1[-6:-3]) #oce
# print(str1[:4])#
# 8.切片+不长
# str1 = "duoceshi"
# print(str1)#seco
# print(str1)#uoce
# print(str1[::])# duoceshi
# print(str1[::-1])#ihsecoud 反转序列
# print(str1[-3:6]) # s
# print(str1[-3:5]) # 值为空
# #9.跳切
# str1 = "duoceshi"
# print(str1)#sc
# print(str1)#uc
# print(str1[:5:2])#doe
# print(str1)# ucsi
# print(str1[::-2])#iscu
#10.字符串
# str1 = "user name"
# print(str1.capitalize()) #capitalize()把字符串的首字母变成大写))User name
# print(str1.title())# title()单词的开头是大写，其他是小写User Name
# print(str1.count("e"))# count("e")统计某个字符出现的次数2
# print("-".join(str1))#join()函数可以按自定义的链接符连接字符串的元素 u-s-e-r- -n-a-m-e
# print("*".join(str1))#u*s*e*r* *n*a*m*e
# print(str1.split())#把字符串通过指定的标识符进行分割，可以把字符串变为列表
# #['user', 'name']
# print(str1.split("e"))#['us', 'r nam', '']
# print(type(str1.split()))# 查看类型，返回的是一个列表<class 'list'>
#
# str1 = "uesernawnamee"
# # print(str1.strip("ue"))#ser nam 删除字符串开头和结尾有u或e的字符
# # print(str1.rstrip("ue"))#uesernawnam 删除字符串结尾有ue的字符
# # print(str1.lstrip("ue"))#sernawnamee删除字符串开头有ue的字符
# print(str1.startswith("u"))# true 判断字符串以什么开头，返回的值是布尔值
# print(str1.startswith("a")) #false
# print(str1.endswith("e"))#true
str1 = "hongqipiaopiao"
# print(str1.find("i"))#5左边开始查
# print(str1.rfind("i"))#11右边开始查
# print(str1.find("o"))#1左边开始查
# print(str1.rfind("o"))#13右边开始查
# print(str1.replace("o","w"))#hwngqipiawpiaw
# print(str1.replace("o","w",1))#hwngqipiaopiao
# print(str1.replace("o","w",2))#hwngqipiawpiao
# str1 = "AGFHbnbbn"
# print(str1.lower())#agfhbnbbn所有的大写变为小写
# print(str1.upper())#AGFHBNBBN所有的小写变为大写
# str1 = "jsd123"
# print(str1.isdigit())#false
# str1 = "123"
# print(str1.isdigit())#true
# str1 = "jsd"
# print(str1.isalpha())#true
str1 = "jsd123"
print(str1.isalnum())#true
str1 = "jsd123*"
print(str1.isalnum())#false
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