day02
数字相关的转换
bin() 2进制
oct() 8进制
hex() 16进制
字符串
定义：它是一个有序的字符的集合，用于存储和表示基本的文本信息，‘’或“”或‘’‘ ’‘’中间包含的内容称之为字符串
特性：
1.只能存放一个值
2.不可变
3.按照从左到右的顺序定义字符集合，下标从0开始顺序访问，有序
补充：
1.字符串的单引号和双引号都无法取消特殊字符的含义，如果想让引号内所有字符均取消特殊意义，在引号前面加r，如name＝r'l hf'
2.unicode字符串与r连用必需在r前面，如name＝ur'l hf'
1 class str(object): 2 def capitalize(self): 3 首字母变大写 4 5 def center(self, width, fillchar=None): 6 原来字符居中，不够用空格补全 7 8 def count(self, sub, start=None, end=None): 9 从一个范围内的统计某str出现次数 10 11 def encode(self, encoding='utf-8', errors='strict'): 12 以encoding指定编码格式编码，如果出错默认报一个ValueError，除非errors指定的是 13 14 def endswith(self, suffix, start=None, end=None): 15 Return True if S ends with the specified suffix, False otherwise. 16 17 def expandtabs(self, tabsize=8): 18 将字符串中包含的 转换成tabsize个空格 19 20 def find(self, sub, start=None, end=None): 21 Return the lowest index in S where substring sub is found 22 23 def format(self, *args, **kwargs): 24 格式化输出 25 三种形式： 26 形式一. 27 >>> print('{0}{1}{0}'.format('a','b')) 28 aba 29 30 形式二：（必须一一对应） 31 >>> print('{}{}{}'.format('a','b')) 32 Traceback (most recent call last): 33 File "<input>", line 1, in <module> 34 IndexError: tuple index out of range 35 >>> print('{}{}'.format('a','b')) 36 37 形式三： 38 >>> print('{name} {age}'.format(age=12,name='lhf')) 39 40 41 def index(self, sub, start=None, end=None): 42 查找第一个出现该字符串的下标 43 44 def isalpha(self): 45 至少一个字符，且都是字母才返回True 46 47 def isdigit(self): 48 如果都是整数，返回True 49 50 def isidentifier(self): 51 字符串为关键字返回True 52 53 def islower(self): 54 至少一个字符，且都是小写字母才返回True 55 56 def isnumeric(self): 57 Return True if there are only numeric characters in S, 58 59 def isspace(self): 60 至少一个字符，且都是空格才返回True 61 62 def istitle(self): 63 首字母大写则返回True 64 65 def isupper(self): # real signature unknown; restored from __doc__ 66 Return True if all cased characters in S are uppercase and there is 67 68 def join(self, iterable): # real signature unknown; restored from __doc__ 69 #对序列进行操作（分别使用' '与':'作为分隔符） 70 >>> seq1 = ['hello','good','boy','doiido'] 71 >>> print ' '.join(seq1) 72 hello good boy doiido 73 >>> print ':'.join(seq1) 74 hello:good:boy:doiido 75 76 77 #对字符串进行操作 78 79 >>> seq2 = "hello good boy doiido" 80 >>> print ':'.join(seq2) 81 h:e:l:l:o: :g:o:o:d: :b:o:y: :d:o:i:i:d:o 82 83 84 #对元组进行操作 85 86 >>> seq3 = ('hello','good','boy','doiido') 87 >>> print ':'.join(seq3) 88 hello:good:boy:doiido 89 90 91 #对字典进行操作 92 93 >>> seq4 = {'hello':1,'good':2,'boy':3,'doiido':4} 94 >>> print ':'.join(seq4) 95 boy:good:doiido:hello 96 97 98 #合并目录 99 100 >>> import os 101 >>> os.path.join('/hello/','good/boy/','doiido') 102 '/hello/good/boy/doiido' 103 104 105 S.join(iterable) -> str 106 107 Return a string which is the concatenation of the strings in the 108 iterable. The separator between elements is S. 109 """ 110 return "" 111 112 def lower(self): 113 """ 114 S.lower() -> str 115 116 Return a copy of the string S converted to lowercase. 117 """ 118 return "" 119 120 def partition(self, sep): 121 以sep为分割，将S分成head,sep,tail三部分 122 123 124 def replace(self, old, new, count=None): 125 S.replace(old, new[, count]) -> str 126 Return a copy of S with all occurrences of substring 127 128 129 def rfind(self, sub, start=None, end=None): 130 S.rfind(sub[, start[, end]]) -> int 131 132 def rindex(self, sub, start=None, end=None): 133 S.rindex(sub[, start[, end]]) -> int 134 135 136 def rsplit(self, sep=None, maxsplit=-1): # real signature unknown; restored from __doc__ 137 """ 138 S.rsplit(sep=None, maxsplit=-1) -> list of strings 139 140 Return a list of the words in S, using sep as the 141 delimiter string, starting at the end of the string and 142 working to the front. If maxsplit is given, at most maxsplit 143 splits are done. If sep is not specified, any whitespace string 144 is a separator. 145 """ 146 return [] 147 148 def rstrip(self, chars=None): # real signature unknown; restored from __doc__ 149 """ 150 S.rstrip([chars]) -> str 151 152 Return a copy of the string S with trailing whitespace removed. 153 If chars is given and not None, remove characters in chars instead. 154 """ 155 return "" 156 157 def split(self, sep=None, maxsplit=-1): # real signature unknown; restored from __doc__ 158 以sep为分割，将S切分成列表，与partition的区别在于切分结果不包含sep， 159 如果一个字符串中包含多个sep那么maxsplit为最多切分成几部分 160 >>> a='a,b c d e' 161 >>> a.split() 162 ['a,b', 'c', 'd', 'e'] 163 164 165 def splitlines(self, keepends=None): # real signature unknown; restored from __doc__ 166 """ 167 Python splitlines() 按照行(' ', ' ', ')分隔， 168 返回一个包含各行作为元素的列表，如果参数 keepends 为 False，不包含换行符，如 果为 True，则保留换行符。 169 >>> x 170 'adsfasdf sadf asdf adf' 171 >>> x.splitlines() 172 ['adsfasdf', 'sadf', 'asdf', 'adf'] 173 >>> x.splitlines(True) 174 ['adsfasdf ', 'sadf ', 'asdf ', 'adf'] 175 176 S.splitlines([keepends]) -> list of strings 177 178 Return a list of the lines in S, breaking at line boundaries. 179 Line breaks are not included in the resulting list unless keepends 180 is given and true. 181 """ 182 return [] 183 184 def startswith(self, prefix, start=None, end=None): # real signature unknown; restored from __doc__ 185 S.startswith(prefix[, start[, end]]) -> bool 186 187 Return True if S starts with the specified prefix, False otherwise. 188 189 190 def strip(self, chars=None): # real signature unknown; restored from __doc__ 191 S.strip([chars]) -> str 192 193 Return a copy of the string S with leading and trailing 194 195 def swapcase(self): # real signature unknown; restored from __doc__ 196 """ 197 大小写反转 198 S.swapcase() -> str 199 200 Return a copy of S with uppercase characters converted to lowercase 201 and vice versa. 202 """ 203 return "" 204 205 def title(self): # real signature unknown; restored from __doc__ 206 """ 207 S.title() -> str 208 209 Return a titlecased version of S, i.e. words start with title case 210 characters, all remaining cased characters have lower case. 211 """ 212 return "" 213 214 def translate(self, table): # real signature unknown; restored from __doc__ 215 """ 216 table=str.maketrans('alex','big SB') 217 218 a='hello abc' 219 print(a.translate(table)) 220 221 S.translate(table) -> str 222 223 Return a copy of the string S in which each character has been mapped 224 through the given translation table. The table must implement 225 lookup/indexing via __getitem__, for instance a dictionary or list, 226 mapping Unicode ordinals to Unicode ordinals, strings, or None. If 227 this operation raises LookupError, the character is left untouched. 228 Characters mapped to None are deleted. 229 """ 230 return "" 231 232 def upper(self): # real signature unknown; restored from __doc__ 233 """ 234 S.upper() -> str 235 236 Return a copy of S converted to uppercase. 237 """ 238 return "" 239 240 def zfill(self, width): # real signature unknown; restored from __doc__ 241 """ 242 原来字符右对齐，不够用0补齐 243 244 S.zfill(width) -> str 245 246 Pad a numeric string S with zeros on the left, to fill a field 247 of the specified width. The string S is never truncated. 248 """ 249 return ""
homework
1 # 1：编写for循环，利用索引遍历出每一个字符 2 # msg='hello egon 666' 3 4 5 msg='hello egon 666' 6 7 for i in range(len(msg)): 8 print(msg[i])
1 # 2：编写while循环，利用索引遍历出每一个字符 2 # msg='hello egon 666' 3 msg='hello egon 666' 4 count = 0 5 6 while count < len(msg): 7 print(msg[count]) 8 count += 1
1 # 3： 2 # msg='hello alex'中的alex替换成SB 3 4 msg='hello alex' 5 6 print(msg) 7 print("修改后：",msg.replace('alex', 'SB'))
1 # 4： 2 # msg='/etc/a.txt|365|get' 3 # 将该字符的文件名，文件大小，操作方法切割出来 4 5 msg='/etc/a.txt|365|get' 6 msg_list = msg.split('|') 7 print(""" 8 打印说明 9 1.文件名：{} 10 2.大 小：{} 11 3.方 法：{} 12 """.format(msg_list[0], msg_list[1], msg_list[2]))
1 # 编写while循环，要求用户输入命令，如果命令为空，则继续输入 2 3 flag = True 4 while flag: 5 if len(input(">>>").strip()) != 0: 6 flag = False 7 continue
1 # 编写while循环，让用户输入用户名和密码，如果用户为空或者数字，则重新输入 2 3 flag = True 4 5 while flag: 6 username = input('username:').strip() 7 password = input('password:').strip() 8 if len(username) != 0 and not username.isdigit(): 9 flag = False 10 continue
1 # 编写while循环，让用户输入内容，判断输入的内容以alex开头的，则将该字符串加上_SB结尾 2 3 while True: 4 s = input(">>>") 5 if s == 'q': 6 break 7 elif s.startswith('alex'): 8 s+='_SB' 9 print(s)
1 # 8. 2 # 1.两层while循环，外层的while循环，让用户输入用户名、密码、工作了几个月、每月的工资（整数），用户名或密码为空，或者工作的月数不为整数，或者 3 # 月工资不为整数，则重新输入 4 # 2.认证成功，进入下一层while循环，打印命令提示，有查询总工资，查询用户身份（如果用户名为alex则打印super user，如果用户名为yuanhao或者wupeiqi 5 # 则打印normal user，其余情况均打印unkown user），退出功能 6 # 3.要求用户输入退出，则退出所有循环（使用tag的方式） 7 flag = True 8 9 10 while flag: 11 username = input('用户名：').strip() 12 password = input('密码：').strip() 13 work_time = input('工作时间：').strip() 14 salary = input('工资：').strip() 15 if len(username) == 0 or len(password) == 0 or not work_time.isdigit() or not salary.isdigit(): 16 continue 17 else: 18 while flag: 19 choose = input("1.查询工资 2.查询身份 3.退出 >>>") 20 if choose == '1': 21 input('%s的工资是%s元'%(username, salary)) 22 elif choose == '2': 23 if username == 'alex': 24 input('supper user') 25 elif username == 'yuanhao' or username == 'wupeiqi': 26 input('normal user') 27 else: 28 input('unkown user') 29 elif choose == '3' or choose == 'q': 30 flag = False 31 else: 32 input("Error")