创建字符串 var1 = "world" var2 = "python" var3 = """ hello world python """ print (var1 var2 var3) 输出结果: world python hello world python
字符串乘法
var1 = "python " print (var1*5) 输出结果: python python python python python
字符串续行(""续行符) var1= """ hello world python """ print (var1) 输出结果: hello world python ----------------------------- 字符串换行 var1= """ hello world python """ print (var1) 输出结果: hello world python 字符串续行(""续行符) var1= """ hello world python """ print (var1) 输出结果: hello world python
字符串的拼接方法一 var1 = "hello" var2 = "python" print (var1 +" "+ var2) 输出结果: hello python
字符串的拼接方法二 例一: var1 = "python" var2 = "world" var3 = ''.jion([a,b]) #引号里面的指用什么隔开 print (var3) 输出结果: pythonworld
例二: var1 = "python" var2 = "world" var3 = ' '.jion([a,b]) #引号里面的指用什么隔开 print (var3) 输出结果: python world 例三: var1 = "python" var2 = "world" var3 = '***'.jion([var1,var2]) print ("var3") 输出结果: python***world 例四: var1 = "python" var2 = "world" var3 = "hello" var4 = '***'.jion([var1,var2,var3]) print ("var3") 输出结果: python***world***hello
通过索引获取字符串中字符a = "python"print (a[1])#从0开始算,截取索引为1的字符输出结果:y
---------------------------------- a = "python" print (a[0:3])#截取0到2的字符,3不算在内 输出结果: pyt ----------------------------------- a = "python" print (a[:])#截取全部字符 输出结果: python ------------------------------------ a = "python" print (a[2:])#截取2后面所有的字符串 输出结果: thon ------------------------------------- a = "python" print (a[-2:]) 输出结果: on ------------------------------------- a = "python" print (a[-3:-1])#-1不算在内,从-2开始算 输出结果: ho ------------------------------------- a = "python" print (a[:-2]) 输出结果: pyth ------------------------------------ a = "python" print (a[-5:-2])#-2不算在内,从--3开始算 输出结果: yth ------------------------------------ a = "python" print (a[::2]) #前面开始,指向后跳一个取(2是步长的意思) 输出结果: pto ------------------------------------- a = "python" print (a[::-2]) #后面开始,向前跳一个取(2是步长的意思) 输出结果: nhy ------------------------------------
a = "python"
print (a[-4]) #使用负数,从字符串的右边向左边反向索引,最右侧索引值是-1
输出结果:
t
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a = "python" print (a[3:3])#取值为空 print (a[3:2])#取值为空 ------------------------------------
反向打印字符串方法一 a = "python" print (a[::-1]) 输出结果: nohtyp ---------------------- 反向打印字符串方法二 reverse() 1、将字符串转换成列表 2、将列表逆向输出 3、再将列表转换成字符串 ----------------------- 例一: a = "python" a1 = list(a) a2 = a1.reverse() a3 = [str(i) for i in range(a2)] ----------------------------------------------------------- in 成员运算符,如果指定的字符在字符串中,输出True否则输出 False a = "python" print( "n" in a) 输出结果: True ----------------------------------------------------------- a = "python" print ("m" in a) 输出结果: False ----------------------------------------------------------- not in 成员运算符,如果指定的字符不在字符串中,输出True,否则输出False a = "python" print ("m" not in a) 输出结果: True ------------------------------------------------------------ a = "python" print ("n" not in a) 输出结果: False
r 在字符串前面加上r 是原始字符串,代表里面的特殊符号没有转义的功能,r不区分大小写 例一: a = r"hello python" print (a) 输出结果: hello python 例二: a = "hello python" # 是换行功能 print (a) 输出结果: hello python
字符串格式化输出 常用占位符,%s %d %f 例一: name = "guohailan" age = 18 print ("我叫 %s , 今年 %d “(name,age)) 输出结果 我叫guohailan,今年18 默认保持六位小数 例二: weight= 18 print ("weight %f") 输出结果: weight:18:00000 可指定小数的位数 例三: weight= 18 print ("weight %.2f") 输出结果: weight:18:00