1.%s,%d
举例1：name='egon'
age=20
print("my name is %s my age is %s" %(name,age))#%s既能接受字符串，也能接受数字
print(‘my name is %s my age is %d’ %(name,age))#%d只能接受数字
举例2：用户信息的显示
1 while True: 2 name=input("name:") 3 age=input("age:") 4 sex=input("sex:") 5 height=input("height:") 6 msg=''' 7 ------------%s info----------- 8 name:%s 9 age:%s 10 sex:%s 11 height:%s 12 ------------------------------ 13 '''%(name,name,age,sex,heigth) 14 print(msg) 运行结果如下：
2.字符串方法
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 | # name='egon' #name=str('egon') # print(type(name)) #优先掌握 #1.移除空白strip # msg=' hello ' # print(msg) # print(msg.strip()) # 移除‘*’ # msg='***hello*********' # msg=msg.strip('*') # print(msg) #移除左边的 # print(msg.lstrip('*')) #移除右边的 # print(msg.rstrip('*')) #用处 while True : name = input ( 'user: ' ).strip() password = input ( 'password: ' ).strip() if name = = 'egon' and password = = '123' : print ( 'login successfull' ) #切分split # info='root:x:0:0::/root:/bin/bash' # print(info[0]+info[1]+info[2]+info[3]) # user_l=info.split(':') # print(user_l[0]) # msg='hello world egon say hahah' # print(msg.split()) #默认以空格作为分隔符 #cmd='download|xhp.mov|3000' # cmd_l=cmd.split('|') # print(cmd_l[1]) # print(cmd_l[0]) # print(cmd.split('|',1)) #用处 while True : cmd = input ( '>>: ' ).strip() if len (cmd) = = 0 : continue cmd_l = cmd.split() print ( '命令是:%s 命令的参数是:%s' % (cmd_l[ 0 ],cmd_l[ 1 ])) #长度len # print(len('hell 123')) #索引 # 切片:切出子字符串 # msg='hello world' # print(msg[1:3]) #1 2 # print(msg[1:4]) #1 2 3 # 掌握部分 oldboy_age = 84 while True : age = input ( '>>: ' ).strip() if len (age) = = 0 : continue if age.isdigit(): age = int (age) else : print ( 'must be int' ) #startswith,endswith # name='alex_SB' # print(name.endswith('SB')) # print(name.startswith('alex')) #replace # name='alex say :i have one tesla,my name is alex' # print(name.replace('alex','SB',1)) # print('my name is %s my age is %s my sex is %s' %('egon',18,'male')) # print('my name is {} my age is {} my sex is {}'.format('egon',18,'male')) # print('my name is {0} my age is {1} my sex is {0}: { 2 } '.format(' egon ',18,' male')) # print('my name is {name} my age is {age} my sex is {sex}'.format( # sex='male', # age=18, # name='egon')) # name='goee say hello' # # print(name.find('S',1,3)) #顾头不顾尾,找不到则返回-1不会报错,找到了则显示索引 # # print(name.index('S')) #同上,但是找不到会报错 # # print(name.count('S',1,5)) #顾头不顾尾,如果不指定范围则查找所有 #join # info='root:x:0:0::/root:/bin/bash' # print(info.split(':')) # l=['root', 'x', '0', '0', '', '/root', '/bin/bash'] # print(':'.join(l)) #lower,upper # name='eGon' # print(name.lower()) # print(name.upper()) #了解部分 #expandtabs # name='egon\thello' # print(name) # print(name.expandtabs(1)) #center,ljust,rjust,zfill # name='egon' # # print(name.center(30,'-')) # print(name.ljust(30,'*')) # print(name.rjust(30,'*')) # print(name.zfill(50)) #用0填充 #captalize,swapcase,title # name='eGon' # print(name.capitalize()) #首字母大写,其余部分小写 # print(name.swapcase()) #大小写翻转 # msg='egon say hi' # print(msg.title()) #每个单词的首字母大写 #在python3中 num0 = '4' num1 = b '4' #bytes num2 = u '4' #unicode,python3中无需加u就是unicode num3 = '四' #中文数字 num4 = 'Ⅳ' #罗马数字 #isdigt:str,bytes,unicode # print(num0.isdigit()) # print(num1.isdigit()) # print(num2.isdigit()) # print(num3.isdigit()) # print(num4.isdigit()) #isdecimal:str,unicode # num0='4' # num1=b'4' #bytes # num2=u'4' #unicode,python3中无需加u就是unicode # num3='四' #中文数字 # num4='Ⅳ' #罗马数字 # print(num0.isdecimal()) # # print(num1.) # print(num2.isdecimal()) # print(num3.isdecimal()) # print(num4.isdecimal()) #isnumeric:str,unicode,中文，罗马 # num0='4' # num1=b'4' #bytes # num2=u'4' #unicode,python3中无需加u就是unicode # num3='四' #中文数字 # num4='Ⅳ' #罗马数字 # # print(num0.isnumeric()) # # print(num1) # print(num2.isnumeric()) # print(num3.isnumeric()) # print(num4.isnumeric()) #is其他 # name='egon123' # print(name.isalnum()) #字符串由字母和数字组成 # name='asdfasdfa sdf' # print(name.isalpha()) #字符串只由字母组成 # # name='asdfor123' # print(name.isidentifier()) name = 'egGon' print (name.islower()) # print(name.isupper()) # print(name.isspace()) name = 'Egon say' print (name.istitle()) |
切片操作（slice）可以从一个字符串中获取子字符串（字符串的一部分）。我们使用一对方括号、起始偏移量start、终止偏移量end 以及可选的步长step 来定义一个分片。
格式： [start:end:step]
- [:] 提取从开头（默认位置0）到结尾（默认位置-1）的整个字符串
- [start:] 从start 提取到结尾
- [:end] 从开头提取到end - 1
- [start:end] 从start 提取到end - 1
- [start:end:step] 从start 提取到end - 1，每step 个字符提取一个
- 左侧第一个字符的位置/偏移量为0，右侧最后一个字符的位置/偏移量为-1
举例： 输入一个字符串，返回倒序排序的结果，：如：‘abcdef’ 返回：'fedcba'
#方式一：将字符串翻转，步长设为-1def re_sort(): s = input('请输入一串字符串：>>') return s[::-1] #从开头到结尾步长为-1# obj = re_sort()# print(obj)#方式二：借助列表进行翻转def re_sort2(): s = input('请输入一串字符串：>>') li = [] for i in s: li.append(i) li.reverse() #将列表反转 return ''.join(li) #将列表转化成字符串 obj2 = re_sort2() print(obj2)