1.字符串表达
'hello python' "hello world"
2.字符串功能
1 class str(object): 2 """ 3 str(object='') -> str 4 str(bytes_or_buffer[, encoding[, errors]]) -> str 5 6 Create a new string object from the given object. If encoding or 7 errors is specified, then the object must expose a data buffer 8 that will be decoded using the given encoding and error handler. 9 Otherwise, returns the result of object.__str__() (if defined) 10 or repr(object). 11 encoding defaults to sys.getdefaultencoding(). 12 errors defaults to 'strict'. 13 """ 14 def capitalize(self): # real signature unknown; restored from __doc__ 15 """ 16 S.capitalize() -> str 17 18 Return a capitalized version of S, i.e. make the first character 19 have upper case and the rest lower case. 20 """ 21 return "" 22 23 def casefold(self): # real signature unknown; restored from __doc__ 24 """ 25 S.casefold() -> str 26 27 Return a version of S suitable for caseless comparisons. 28 """ 29 return "" 30 31 def center(self, width, fillchar=None): # real signature unknown; restored from __doc__ 32 """ 33 S.center(width[, fillchar]) -> str 34 35 Return S centered in a string of length width. Padding is 36 done using the specified fill character (default is a space) 37 """ 38 return "" 39 40 def count(self, sub, start=None, end=None): # real signature unknown; restored from __doc__ 41 """ 42 S.count(sub[, start[, end]]) -> int 43 44 Return the number of non-overlapping occurrences of substring sub in 45 string S[start:end]. Optional arguments start and end are 46 interpreted as in slice notation. 47 """ 48 return 0 49 50 def encode(self, encoding='utf-8', errors='strict'): # real signature unknown; restored from __doc__ 51 """ 52 S.encode(encoding='utf-8', errors='strict') -> bytes 53 54 Encode S using the codec registered for encoding. Default encoding 55 is 'utf-8'. errors may be given to set a different error 56 handling scheme. Default is 'strict' meaning that encoding errors raise 57 a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and 58 'xmlcharrefreplace' as well as any other name registered with 59 codecs.register_error that can handle UnicodeEncodeErrors. 60 """ 61 return b"" 62 63 def endswith(self, suffix, start=None, end=None): # real signature unknown; restored from __doc__ 64 """ 65 S.endswith(suffix[, start[, end]]) -> bool 66 67 Return True if S ends with the specified suffix, False otherwise. 68 With optional start, test S beginning at that position. 69 With optional end, stop comparing S at that position. 70 suffix can also be a tuple of strings to try. 71 """ 72 return False 73 74 def expandtabs(self, tabsize=8): # real signature unknown; restored from __doc__ 75 """ 76 S.expandtabs(tabsize=8) -> str 77 78 Return a copy of S where all tab characters are expanded using spaces. 79 If tabsize is not given, a tab size of 8 characters is assumed. 80 """ 81 return "" 82 83 def find(self, sub, start=None, end=None): # real signature unknown; restored from __doc__ 84 """ 85 S.find(sub[, start[, end]]) -> int 86 87 Return the lowest index in S where substring sub is found, 88 such that sub is contained within S[start:end]. Optional 89 arguments start and end are interpreted as in slice notation. 90 91 Return -1 on failure. 92 """ 93 return 0 94 95 def format(self, *args, **kwargs): # known special case of str.format 96 """ 97 S.format(*args, **kwargs) -> str 98 99 Return a formatted version of S, using substitutions from args and kwargs. 100 The substitutions are identified by braces ('{' and '}'). 101 """ 102 pass 103 104 def format_map(self, mapping): # real signature unknown; restored from __doc__ 105 """ 106 S.format_map(mapping) -> str 107 108 Return a formatted version of S, using substitutions from mapping. 109 The substitutions are identified by braces ('{' and '}'). 110 """ 111 return "" 112 113 def index(self, sub, start=None, end=None): # real signature unknown; restored from __doc__ 114 """ 115 S.index(sub[, start[, end]]) -> int 116 117 Like S.find() but raise ValueError when the substring is not found. 118 """ 119 return 0 120 121 def isalnum(self): # real signature unknown; restored from __doc__ 122 """ 123 S.isalnum() -> bool 124 125 Return True if all characters in S are alphanumeric 126 and there is at least one character in S, False otherwise. 127 """ 128 return False 129 130 def isalpha(self): # real signature unknown; restored from __doc__ 131 """ 132 S.isalpha() -> bool 133 134 Return True if all characters in S are alphabetic 135 and there is at least one character in S, False otherwise. 136 """ 137 return False 138 139 def isdecimal(self): # real signature unknown; restored from __doc__ 140 """ 141 S.isdecimal() -> bool 142 143 Return True if there are only decimal characters in S, 144 False otherwise. 145 """ 146 return False 147 148 def isdigit(self): # real signature unknown; restored from __doc__ 149 """ 150 S.isdigit() -> bool 151 152 Return True if all characters in S are digits 153 and there is at least one character in S, False otherwise. 154 """ 155 return False 156 157 def isidentifier(self): # real signature unknown; restored from __doc__ 158 """ 159 S.isidentifier() -> bool 160 161 Return True if S is a valid identifier according 162 to the language definition. 163 164 Use keyword.iskeyword() to test for reserved identifiers 165 such as "def" and "class". 166 """ 167 return False 168 169 def islower(self): # real signature unknown; restored from __doc__ 170 """ 171 S.islower() -> bool 172 173 Return True if all cased characters in S are lowercase and there is 174 at least one cased character in S, False otherwise. 175 """ 176 return False 177 178 def isnumeric(self): # real signature unknown; restored from __doc__ 179 """ 180 S.isnumeric() -> bool 181 182 Return True if there are only numeric characters in S, 183 False otherwise. 184 """ 185 return False 186 187 def isprintable(self): # real signature unknown; restored from __doc__ 188 """ 189 S.isprintable() -> bool 190 191 Return True if all characters in S are considered 192 printable in repr() or S is empty, False otherwise. 193 """ 194 return False 195 196 def isspace(self): # real signature unknown; restored from __doc__ 197 """ 198 S.isspace() -> bool 199 200 Return True if all characters in S are whitespace 201 and there is at least one character in S, False otherwise. 202 """ 203 return False 204 205 def istitle(self): # real signature unknown; restored from __doc__ 206 """ 207 S.istitle() -> bool 208 209 Return True if S is a titlecased string and there is at least one 210 character in S, i.e. upper- and titlecase characters may only 211 follow uncased characters and lowercase characters only cased ones. 212 Return False otherwise. 213 """ 214 return False 215 216 def isupper(self): # real signature unknown; restored from __doc__ 217 """ 218 S.isupper() -> bool 219 220 Return True if all cased characters in S are uppercase and there is 221 at least one cased character in S, False otherwise. 222 """ 223 return False 224 225 def join(self, iterable): # real signature unknown; restored from __doc__ 226 """ 227 S.join(iterable) -> str 228 229 Return a string which is the concatenation of the strings in the 230 iterable. The separator between elements is S. 231 """ 232 return "" 233 234 def ljust(self, width, fillchar=None): # real signature unknown; restored from __doc__ 235 """ 236 S.ljust(width[, fillchar]) -> str 237 238 Return S left-justified in a Unicode string of length width. Padding is 239 done using the specified fill character (default is a space). 240 """ 241 return "" 242 243 def lower(self): # real signature unknown; restored from __doc__ 244 """ 245 S.lower() -> str 246 247 Return a copy of the string S converted to lowercase. 248 """ 249 return "" 250 251 def lstrip(self, chars=None): # real signature unknown; restored from __doc__ 252 """ 253 S.lstrip([chars]) -> str 254 255 Return a copy of the string S with leading whitespace removed. 256 If chars is given and not None, remove characters in chars instead. 257 """ 258 return "" 259 260 def maketrans(self, *args, **kwargs): # real signature unknown 261 """ 262 Return a translation table usable for str.translate(). 263 264 If there is only one argument, it must be a dictionary mapping Unicode 265 ordinals (integers) or characters to Unicode ordinals, strings or None. 266 Character keys will be then converted to ordinals. 267 If there are two arguments, they must be strings of equal length, and 268 in the resulting dictionary, each character in x will be mapped to the 269 character at the same position in y. If there is a third argument, it 270 must be a string, whose characters will be mapped to None in the result. 271 """ 272 pass 273 274 def partition(self, sep): # real signature unknown; restored from __doc__ 275 """ 276 S.partition(sep) -> (head, sep, tail) 277 278 Search for the separator sep in S, and return the part before it, 279 the separator itself, and the part after it. If the separator is not 280 found, return S and two empty strings. 281 """ 282 pass 283 284 def replace(self, old, new, count=None): # real signature unknown; restored from __doc__ 285 """ 286 S.replace(old, new[, count]) -> str 287 288 Return a copy of S with all occurrences of substring 289 old replaced by new. If the optional argument count is 290 given, only the first count occurrences are replaced. 291 """ 292 return "" 293 294 def rfind(self, sub, start=None, end=None): # real signature unknown; restored from __doc__ 295 """ 296 S.rfind(sub[, start[, end]]) -> int 297 298 Return the highest index in S where substring sub is found, 299 such that sub is contained within S[start:end]. Optional 300 arguments start and end are interpreted as in slice notation. 301 302 Return -1 on failure. 303 """ 304 return 0 305 306 def rindex(self, sub, start=None, end=None): # real signature unknown; restored from __doc__ 307 """ 308 S.rindex(sub[, start[, end]]) -> int 309 310 Like S.rfind() but raise ValueError when the substring is not found. 311 """ 312 return 0 313 314 def rjust(self, width, fillchar=None): # real signature unknown; restored from __doc__ 315 """ 316 S.rjust(width[, fillchar]) -> str 317 318 Return S right-justified in a string of length width. Padding is 319 done using the specified fill character (default is a space). 320 """ 321 return "" 322 323 def rpartition(self, sep): # real signature unknown; restored from __doc__ 324 """ 325 S.rpartition(sep) -> (head, sep, tail) 326 327 Search for the separator sep in S, starting at the end of S, and return 328 the part before it, the separator itself, and the part after it. If the 329 separator is not found, return two empty strings and S. 330 """ 331 pass 332 333 def rsplit(self, sep=None, maxsplit=-1): # real signature unknown; restored from __doc__ 334 """ 335 S.rsplit(sep=None, maxsplit=-1) -> list of strings 336 337 Return a list of the words in S, using sep as the 338 delimiter string, starting at the end of the string and 339 working to the front. If maxsplit is given, at most maxsplit 340 splits are done. If sep is not specified, any whitespace string 341 is a separator. 342 """ 343 return [] 344 345 def rstrip(self, chars=None): # real signature unknown; restored from __doc__ 346 """ 347 S.rstrip([chars]) -> str 348 349 Return a copy of the string S with trailing whitespace removed. 350 If chars is given and not None, remove characters in chars instead. 351 """ 352 return "" 353 354 def split(self, sep=None, maxsplit=-1): # real signature unknown; restored from __doc__ 355 """ 356 S.split(sep=None, maxsplit=-1) -> list of strings 357 358 Return a list of the words in S, using sep as the 359 delimiter string. If maxsplit is given, at most maxsplit 360 splits are done. If sep is not specified or is None, any 361 whitespace string is a separator and empty strings are 362 removed from the result. 363 """ 364 return [] 365 366 def splitlines(self, keepends=None): # real signature unknown; restored from __doc__ 367 """ 368 S.splitlines([keepends]) -> list of strings 369 370 Return a list of the lines in S, breaking at line boundaries. 371 Line breaks are not included in the resulting list unless keepends 372 is given and true. 373 """ 374 return [] 375 376 def startswith(self, prefix, start=None, end=None): # real signature unknown; restored from __doc__ 377 """ 378 S.startswith(prefix[, start[, end]]) -> bool 379 380 Return True if S starts with the specified prefix, False otherwise. 381 With optional start, test S beginning at that position. 382 With optional end, stop comparing S at that position. 383 prefix can also be a tuple of strings to try. 384 """ 385 return False 386 387 def strip(self, chars=None): # real signature unknown; restored from __doc__ 388 """ 389 S.strip([chars]) -> str 390 391 Return a copy of the string S with leading and trailing 392 whitespace removed. 393 If chars is given and not None, remove characters in chars instead. 394 """ 395 return "" 396 397 def swapcase(self): # real signature unknown; restored from __doc__ 398 """ 399 S.swapcase() -> str 400 401 Return a copy of S with uppercase characters converted to lowercase 402 and vice versa. 403 """ 404 return "" 405 406 def title(self): # real signature unknown; restored from __doc__ 407 """ 408 S.title() -> str 409 410 Return a titlecased version of S, i.e. words start with title case 411 characters, all remaining cased characters have lower case. 412 """ 413 return "" 414 415 def translate(self, table): # real signature unknown; restored from __doc__ 416 """ 417 S.translate(table) -> str 418 419 Return a copy of the string S in which each character has been mapped 420 through the given translation table. The table must implement 421 lookup/indexing via __getitem__, for instance a dictionary or list, 422 mapping Unicode ordinals to Unicode ordinals, strings, or None. If 423 this operation raises LookupError, the character is left untouched. 424 Characters mapped to None are deleted. 425 """ 426 return "" 427 428 def upper(self): # real signature unknown; restored from __doc__ 429 """ 430 S.upper() -> str 431 432 Return a copy of S converted to uppercase. 433 """ 434 return "" 435 436 def zfill(self, width): # real signature unknown; restored from __doc__ 437 """ 438 S.zfill(width) -> str 439 440 Pad a numeric string S with zeros on the left, to fill a field 441 of the specified width. The string S is never truncated. 442 """ 443 return "" 444 445 def __add__(self, *args, **kwargs): # real signature unknown 446 """ Return self+value. """ 447 pass 448 449 def __contains__(self, *args, **kwargs): # real signature unknown 450 """ Return key in self. """ 451 pass 452 453 def __eq__(self, *args, **kwargs): # real signature unknown 454 """ Return self==value. """ 455 pass 456 457 def __format__(self, format_spec): # real signature unknown; restored from __doc__ 458 """ 459 S.__format__(format_spec) -> str 460 461 Return a formatted version of S as described by format_spec. 462 """ 463 return "" 464 465 def __getattribute__(self, *args, **kwargs): # real signature unknown 466 """ Return getattr(self, name). """ 467 pass 468 469 def __getitem__(self, *args, **kwargs): # real signature unknown 470 """ Return self[key]. """ 471 pass 472 473 def __getnewargs__(self, *args, **kwargs): # real signature unknown 474 pass 475 476 def __ge__(self, *args, **kwargs): # real signature unknown 477 """ Return self>=value. """ 478 pass 479 480 def __gt__(self, *args, **kwargs): # real signature unknown 481 """ Return self>value. """ 482 pass 483 484 def __hash__(self, *args, **kwargs): # real signature unknown 485 """ Return hash(self). """ 486 pass 487 488 def __init__(self, value='', encoding=None, errors='strict'): # known special case of str.__init__ 489 """ 490 str(object='') -> str 491 str(bytes_or_buffer[, encoding[, errors]]) -> str 492 493 Create a new string object from the given object. If encoding or 494 errors is specified, then the object must expose a data buffer 495 that will be decoded using the given encoding and error handler. 496 Otherwise, returns the result of object.__str__() (if defined) 497 or repr(object). 498 encoding defaults to sys.getdefaultencoding(). 499 errors defaults to 'strict'. 500 # (copied from class doc) 501 """ 502 pass 503 504 def __iter__(self, *args, **kwargs): # real signature unknown 505 """ Implement iter(self). """ 506 pass 507 508 def __len__(self, *args, **kwargs): # real signature unknown 509 """ Return len(self). """ 510 pass 511 512 def __le__(self, *args, **kwargs): # real signature unknown 513 """ Return self<=value. """ 514 pass 515 516 def __lt__(self, *args, **kwargs): # real signature unknown 517 """ Return self<value. """ 518 pass 519 520 def __mod__(self, *args, **kwargs): # real signature unknown 521 """ Return self%value. """ 522 pass 523 524 def __mul__(self, *args, **kwargs): # real signature unknown 525 """ Return self*value.n """ 526 pass 527 528 @staticmethod # known case of __new__ 529 def __new__(*args, **kwargs): # real signature unknown 530 """ Create and return a new object. See help(type) for accurate signature. """ 531 pass 532 533 def __ne__(self, *args, **kwargs): # real signature unknown 534 """ Return self!=value. """ 535 pass 536 537 def __repr__(self, *args, **kwargs): # real signature unknown 538 """ Return repr(self). """ 539 pass 540 541 def __rmod__(self, *args, **kwargs): # real signature unknown 542 """ Return value%self. """ 543 pass 544 545 def __rmul__(self, *args, **kwargs): # real signature unknown 546 """ Return self*value. """ 547 pass 548 549 def __sizeof__(self): # real signature unknown; restored from __doc__ 550 """ S.__sizeof__() -> size of S in memory, in bytes """ 551 pass 552 553 def __str__(self, *args, **kwargs): # real signature unknown 554 """ Return str(self). """ 555 pass
查看字符串属性:dir()
1 a='python' 2 dir(a) 3 4 #运行后结果 5 ['__add__', '__class__', '__contains__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getat 6 tribute__', '__getitem__', '__getnewargs__', '__gt__', '__hash__', '__init__', '__iter__', '__le__', '__len__', '__lt__' 7 , '__mod__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmod__', '__rmul__', '__setat 8 tr__', '__sizeof__', '__str__', '__subclasshook__', 'capitalize', 'casefold', 'center', 'count', 'encode', 'endswith', ' 9 expandtabs', 'find', 'format', 'format_map', 'index', 'isalnum', 'isalpha', 'isdecimal', 'isdigit', 'isidentifier', 'isl 10 ower', 'isnumeric', 'isprintable', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'maketrans', 'pa 11 rtition', 'replace', 'rfind', 'rindex', 'rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 12 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']
3.部分功能介绍
1）移除空格或字符【strip()；lstrip()；rstrip()】
strip(self, chars=None)
删除字符串中开头、结尾处的chars字符,返回一个新字符串，默认参数为空。
lstrip(self, chars=None)
删除字符串中开头处的chars字符，返回一个新字符串，默认参数为空。
rstrip(self, chars=None)
删除字符串中结尾处的chars字符，返回一个新字符串，默认参数为空。
1 s=' python ' 2 a=s.strip() 3 b=s.lstrip() 4 c=s.rstrip() 5 print(s) 6 print(a) 7 print(b) 8 print(c) 9 10 #运行结果 11 python 12 python 13 python 14 python 15 16 s='apythona' 17 a=s.strip('a') 18 b=s.lstrip('a') 19 c=s.rstrip('a') 20 print(s) 21 print(a) 22 print(b) 23 print(c) 24 25 #运行结果 26 apythona 27 python 28 pythona 29 apython
2) capitalize(self):【首字母变大写】
把字符串首字母变大写，返回一个新字符串。
1 s='python' 2 a=s.capitalize() 3 print(s) 4 print(a) 5 6 #运行结果 7 python 8 Python
3)center(self, width, fillchar=None):【字符串内容居中】
字符串在给定的字符串长度width中内容居中，两边用提供的字符fillchar填充，fillchar默认为空，返回一个新字符串。
1 s='python' 2 a=s.center(10) 3 b=s.center(10,'#') 4 print(s) 5 print(a) 6 print(b) 7 8 #运行结果 9 python 10 python 11 ##python##
4）count(self, sub, start=None, end=None):
在指定位置start与end之间，计算sub字符的数量，start与end默认为None,返回一个int数值。
1 s= 'hello world' 2 a=s.count('o') 3 b=s.count('o',6,11) 4 c=s.count('o',6,15) 5 d=s.count('o',5,-4) 6 f=s.count('o',-5,-3) 7 print(a) 8 print(b) 9 print(c) 10 print(d) 11 print(f) 12 13 #运行结果 14 2 15 1 16 1 17 0 18 1
5)endswith(self, suffix, start=None, end=None):
判断字符串在start与end位置之间是不是以某个子序列suffix结尾，返回一个布尔值。【startswith（）是判断字符串在start与end位置之间是不是以某个子序列suffix开头，用法和endswith相同】
1 name='olive' 2 res=name.endswith('e') 3 res1=name.endswith('e',0,4) 4 print(res) 5 print(res1) 6 7 #运行结果 8 True 9 False
6)expandtabs(self, tabsize=8):
把字符串中tab字符替换成tabsize-1个字节的空字符,tabsize默认值为8，返回一个新字符串。
1 s='a\tbc' 2 res=s.expandtabs() 3 res1=s.expandtabs(12) 4 print(s,len(s)) 5 print(res,len(res)) 6 print(res1,len(res1)) 7 8 #运行结果 9 a bc 4 10 a bc 10 11 a bc 14
7）find(self, sub, start=None, end=None):
找字符串在start与end位置间子序列sub最开始出现的位置，start与end默认为None，返回一个int值，字符串不含sub子序列，则返回-1。【rfind()从右找字符串在start与end位置间子序列sub最开始出现的位置，用法和find（）相同】
1 s='aabbbcccc' 2 res=s.find('b') 3 res1=s.find('b',3) 4 res2=s.find('d') 5 print(res) 6 print(res1) 7 print(res2) 8 9 #运行结果 10 2 11 3 12 -1
8）index(self, sub, start=None, end=None):
索引，功能和find（）一样，但是当字符串不含sub子序列时，报ValueError错误。【rindex()从右找字符，用法与index（）相同】
1 s='aabbbcccc' 2 res=s.index('b') 3 res1=s.index('b',3,) 4 print(res) 5 print(res1) 6 7 #运行结果 8 2 9 3 10 11 s='aabbbcccc' 12 res2=s.index('d') 13 print(res2) 14 15 #运行上面这个结果则为 16 ValueError: substring not found
9）format(self, *args, **kwargs):
返回一个格式化的字符串，使用参数被替换，替换由{}标识。与占位符（%f,%d,%s,%x)格式化功能差不多，下面一起举例。
1 s='I am {},like {}' #{}可以写上序号，也可以不写，序号从0开始 2 s1='I am {name},like {obj}' 3 s2='I am {1} ,like {0}' #可以是反序 4 s3='I am %s,like %s' 5 res=s.format('olive','lotus') 6 res1=s1.format(name='olive',obj='lotus') 7 res2=s2.format('olive','lotus') 8 res3=s3%('olive','lotus') #占位符格式化 9 print(res) 10 print(res1) 11 print(res2) 12 print(res3) 13 14 #运行结果 15 I am olive,like lotus 16 I am olive,like lotus 17 I am lotus ,like olive 18 I am olive,like lotus
10）join(self, iterable):
连接iterable列表里的字符串，返回字符串。
1 s=['p','y','t','h','o','n'] 2 res=''.join(s) 3 res1='*'.join(s) #''给出连接分隔符 4 print(res) 5 print(res1) 6 7 运行结果 8 python 9 p*y*t*h*o*n
11）partition(self, sep):
以sep为分隔符，把字符串分割，返回一个元组。【rpartition()从右查找sep，用法与partition()相同】
1 s = 'olivelikelotus' 2 res=s.partition('like') 3 print(res,type(res)) 4 5 #运行结果 6 ('olive', 'like', 'lotus') <class 'tuple'>
12）replace(self, old, new, count=None):
把字符串中某个子序列old替换成一个新序列new，count是替换数，返回一个新字符串。
1 s = 'olivelikelotus' 2 res=s.replace('l','*') 3 res1=s.replace('l','*s',2) 4 print(res) 5 print(res1) 6 7 #运行结果 8 o*ive*ike*otus 9 o*sive*sikelotus
13）split(self, sep=None, maxsplit=-1):
把字符串以sep为分隔符分割，sep作为分隔符会被删除，maxsplit为分割次数，返回一个列表。【rsplit()是从右找sep，splitlines()是按行分割，用法与都split()相同】
1 s = 'olivelikelotus' 2 s1 = 'olive like lotus' 3 res=s.split() 4 res1=s.split('l',1) 5 res2=s1.split() 6 res3=s1.split(' ',1) 7 print(res) 8 print(res1) 9 print(res2) 10 print(res3) 11 12 #运行结果 13 ['olivelikelotus'] 14 ['o', 'ivelikelotus'] 15 ['olive', 'like', 'lotus'] 16 ['olive', 'like lotus']
14）字符串切片（slice）
从一个字符串中截取字符串，格式： [start:end:step]，start与end是截取起始结束位置，step是截取间隔。
1 s = 'iamolivelikecherry!' 2 sed=s[3:-1] 3 sed2=s[::2] 4 sed3=s[:-1] 5 sed4=s[3:] 6 7 print(sed) 8 print(sed2) 9 print(sed3) 10 print(sed4) 11 12 #运行结果 13 olivelikecherry 14 imlvlkcer! 15 iamolivelikecherry 16 olivelikecherry!
15）__add__(self, *args, **kwargs):
在原字符串上加上一个子序列，返回一个字符串。
1 s='abc' 2 res=s.__add__('def') 3 print(res,type(res)) 4 5 #运行结果 6 abcdef <class 'str'>
16）__contains__(self, *args, **kwargs):
判断字符串包不包含给出的参数，返回布尔值。
功能和in相同。
1 name='python' 2 result= name.__contains__('o') 3 result1='ho' in name 4 print(result) 5 print(result1) 6 7 #运行结果 8 True 9 True
17）__eq__(self, *args, **kwargs):
判断字符串是否与查找的字符串一样，返回布尔值。【__ge__()、__gt__()、__le__()、__lt__()用法和__eq__()相同】
1 s='abc' 2 res=s.__eq__('a') 3 res1=s.__eq__('abc') 4 print(res) 5 print(res1) 6 7 #运行结果 8 False 9 True
