2.1.Python字符串处理（去掉空格或者特殊字符 替换操作 查找操作 判断操作 分割合

2.1.Python字符串处理

2.1.1.去掉空格或者特殊字符

2.1.2.替换操作

2.1.3.查找操作

2.1.4.判断操作

2.1.5.分割合并操作

2.1.6.字符串文档

2.1.Python字符串处理

2.1.1.去掉空格或者特殊字符

# -*- coding: UTF-8 -*-"""1、去掉空格或者特殊字符"""input_str = ' 今天天气不错，今天挺风和日丽的 '# 去掉两边的空格print(input_str.strip())# 去掉右边的空格print(input_str.rstrip())# 去掉左边的空格print(input_str.lstrip())input_str = 'AAA今天天气不错，挺风和日丽的AAA'# 去掉所有带A字符的print(input_str.strip('A'))# 去掉左边边含有A的print(input_str.lstrip('A'))# 去掉右边含有A的print(input_str.rstrip('A'))

效果如下：

2.1.2.替换操作

# -*- coding: UTF-8 -*-input_str = 'AAA今天天气不错，挺风和日丽的AAA'"""2、替换操作"""print(input_str.replace('今天','昨天'))'''输出结果：AAA昨天天气不错，挺风和日丽的AAA'''print(input_str.replace('今天',''))'''输出结果：AAA天气不错，挺风和日丽的AAA'''

2.1.3.查找操作

# -*- coding: UTF-8 -*-input_str = 'AAA今天天气不错，挺风和日丽的AAA'print(input_str.find('今天'))"""输出结果：3"""

2.1.4.判断操作

# -*- coding: UTF-8 -*-input_str = '123'print(input_str.isalpha())'''输出结果：False'''print(input_str.isdigit())'''输出结果：True'''

2.1.5.分割合并操作

# -*- coding: UTF-8 -*-input_str = '今天 天气 不错，今天 挺 风和日丽 的'input_str = input_str.split(' ')print(input_str)'''输出结果：['今天', '天气', '不错，今天', '挺', '风和日丽', '的']'''print(''.join(input_str))'''输出结果：今天天气不错，今天挺风和日丽的'''

2.1.6.字符串文档

Help on class str in module builtins:class str(object)| str(object='') -> str| str(bytes_or_buffer[, encoding[, errors]]) -> str| | Create a new string object from the given object. If encoding or| errors is specified, then the object must expose a data buffer| that will be decoded using the given encoding and error handler.| Otherwise, returns the result of object.__str__() (if defined)| or repr(object).| encoding defaults to sys.getdefaultencoding().| errors defaults to 'strict'.| | Methods defined here:| | __add__(self, value, /)|Return self+value.| | __contains__(self, key, /)|Return key in self.| | __eq__(self, value, /)|Return self==value.| | __format__(self, format_spec, /)|Return a formatted version of the string as described by format_spec.| | __ge__(self, value, /)|Return self>=value.| | __getattribute__(self, name, /)|Return getattr(self, name).| | __getitem__(self, key, /)|Return self[key].| | __getnewargs__(...)| | __gt__(self, value, /)|Return self>value.| | __hash__(self, /)|Return hash(self).| | __iter__(self, /)|Implement iter(self).| | __le__(self, value, /)|Return self<=value.| | __len__(self, /)|Return len(self).| | __lt__(self, value, /)|Return self<value.| | __mod__(self, value, /)|Return self%value.| | __mul__(self, value, /)|Return self*value.| | __ne__(self, value, /)|Return self!=value.| | __repr__(self, /)|Return repr(self).| | __rmod__(self, value, /)|Return value%self.| | __rmul__(self, value, /)|Return value*self.| | __sizeof__(self, /)|Return the size of the string in memory, in bytes.| | __str__(self, /)|Return str(self).| | capitalize(self, /)|Return a capitalized version of the string.||More specifically, make the first character have upper case and the rest lower|case.| | casefold(self, /)|Return a version of the string suitable for caseless comparisons.| | center(self, width, fillchar=' ', /)|Return a centered string of length width.||Padding is done using the specified fill character (default is a space).| | count(...)|S.count(sub[, start[, end]]) -> int||Return the number of non-overlapping occurrences of substring sub in|string S[start:end]. Optional arguments start and end are|interpreted as in slice notation.| | encode(self, /, encoding='utf-8', errors='strict')|Encode the string using the codec registered for encoding.||encoding| The encoding in which to encode the string.|errors| The error handling scheme to use for encoding errors.| The default is 'strict' meaning that encoding errors raise a| UnicodeEncodeError. Other possible values are 'ignore', 'replace' and| 'xmlcharrefreplace' as well as any other name registered with| codecs.register_error that can handle UnicodeEncodeErrors.| | endswith(...)|S.endswith(suffix[, start[, end]]) -> bool||Return True if S ends with the specified suffix, False otherwise.|With optional start, test S beginning at that position.|With optional end, stop comparing S at that position.|suffix can also be a tuple of strings to try.| | expandtabs(self, /, tabsize=8)|Return a copy where all tab characters are expanded using spaces.||If tabsize is not given, a tab size of 8 characters is assumed.| | find(...)|S.find(sub[, start[, end]]) -> int||Return the lowest index in S where substring sub is found,|such that sub is contained within S[start:end]. Optional|arguments start and end are interpreted as in slice notation.||Return -1 on failure.| | format(...)|S.format(*args, **kwargs) -> str||Return a formatted version of S, using substitutions from args and kwargs.|The substitutions are identified by braces ('{' and '}').| | format_map(...)|S.format_map(mapping) -> str||Return a formatted version of S, using substitutions from mapping.|The substitutions are identified by braces ('{' and '}').| | index(...)|S.index(sub[, start[, end]]) -> int||Return the lowest index in S where substring sub is found,|such that sub is contained within S[start:end]. Optional|arguments start and end are interpreted as in slice notation.||Raises ValueError when the substring is not found.| | isalnum(self, /)|Return True if the string is an alpha-numeric string, False otherwise.||A string is alpha-numeric if all characters in the string are alpha-numeric and|there is at least one character in the string.| | isalpha(self, /)|Return True if the string is an alphabetic string, False otherwise.||A string is alphabetic if all characters in the string are alphabetic and there|is at least one character in the string.| | isascii(self, /)|Return True if all characters in the string are ASCII, False otherwise.||ASCII characters have code points in the range U+0000-U+007F.|Empty string is ASCII too.| | isdecimal(self, /)|Return True if the string is a decimal string, False otherwise.||A string is a decimal string if all characters in the string are decimal and|there is at least one character in the string.| | isdigit(self, /)|Return True if the string is a digit string, False otherwise.||A string is a digit string if all characters in the string are digits and there|is at least one character in the string.| | isidentifier(self, /)|Return True if the string is a valid Python identifier, False otherwise.||Call keyword.iskeyword(s) to test whether string s is a reserved identifier,|such as "def" or "class".| | islower(self, /)|Return True if the string is a lowercase string, False otherwise.||A string is lowercase if all cased characters in the string are lowercase and|there is at least one cased character in the string.| | isnumeric(self, /)|Return True if the string is a numeric string, False otherwise.||A string is numeric if all characters in the string are numeric and there is at|least one character in the string.| | isprintable(self, /)|Return True if the string is printable, False otherwise.||A string is printable if all of its characters are considered printable in|repr() or if it is empty.| | isspace(self, /)|Return True if the string is a whitespace string, False otherwise.||A string is whitespace if all characters in the string are whitespace and there|is at least one character in the string.| | istitle(self, /)|Return True if the string is a title-cased string, False otherwise.||In a title-cased string, upper- and title-case characters may only|follow uncased characters and lowercase characters only cased ones.| | isupper(self, /)|Return True if the string is an uppercase string, False otherwise.||A string is uppercase if all cased characters in the string are uppercase and|there is at least one cased character in the string.| | join(self, iterable, /)|Concatenate any number of strings.||The string whose method is called is inserted in between each given string.|The result is returned as a new string.||Example: '.'.join(['ab', 'pq', 'rs']) -> 'ab.pq.rs'| | ljust(self, width, fillchar=' ', /)|Return a left-justified string of length width.||Padding is done using the specified fill character (default is a space).| | lower(self, /)|Return a copy of the string converted to lowercase.| | lstrip(self, chars=None, /)|Return a copy of the string with leading whitespace removed.||If chars is given and not None, remove characters in chars instead.| | partition(self, sep, /)|Partition the string into three parts using the given separator.||This will search for the separator in the string. If the separator is found,|returns a 3-tuple containing the part before the separator, the separator|itself, and the part after it.||If the separator is not found, returns a 3-tuple containing the original string|and two empty strings.| | replace(self, old, new, count=-1, /)|Return a copy with all occurrences of substring old replaced by new.|| count|Maximum number of occurrences to replace.|-1 (the default value) means replace all occurrences.||If the optional argument count is given, only the first count occurrences are|replaced.| | rfind(...)|S.rfind(sub[, start[, end]]) -> int||Return the highest index in S where substring sub is found,|such that sub is contained within S[start:end]. Optional|arguments start and end are interpreted as in slice notation.||Return -1 on failure.| | rindex(...)|S.rindex(sub[, start[, end]]) -> int||Return the highest index in S where substring sub is found,|such that sub is contained within S[start:end]. Optional|arguments start and end are interpreted as in slice notation.||Raises ValueError when the substring is not found.| | rjust(self, width, fillchar=' ', /)|Return a right-justified string of length width.||Padding is done using the specified fill character (default is a space).| | rpartition(self, sep, /)|Partition the string into three parts using the given separator.||This will search for the separator in the string, starting at the end. If|the separator is found, returns a 3-tuple containing the part before the|separator, the separator itself, and the part after it.||If the separator is not found, returns a 3-tuple containing two empty strings|and the original string.| | rsplit(self, /, sep=None, maxsplit=-1)|Return a list of the words in the string, using sep as the delimiter string.|| sep|The delimiter according which to split the string.|None (the default value) means split according to any whitespace,|and discard empty strings from the result.| maxsplit|Maximum number of splits to do.|-1 (the default value) means no limit.||Splits are done starting at the end of the string and working to the front.| | rstrip(self, chars=None, /)|Return a copy of the string with trailing whitespace removed.||If chars is given and not None, remove characters in chars instead.| | split(self, /, sep=None, maxsplit=-1)|Return a list of the words in the string, using sep as the delimiter string.||sep| The delimiter according which to split the string.| None (the default value) means split according to any whitespace,| and discard empty strings from the result.|maxsplit| Maximum number of splits to do.| -1 (the default value) means no limit.| | splitlines(self, /, keepends=False)|Return a list of the lines in the string, breaking at line boundaries.||Line breaks are not included in the resulting list unless keepends is given and|true.| | startswith(...)|S.startswith(prefix[, start[, end]]) -> bool||Return True if S starts with the specified prefix, False otherwise.|With optional start, test S beginning at that position.|With optional end, stop comparing S at that position.|prefix can also be a tuple of strings to try.| | strip(self, chars=None, /)|Return a copy of the string with leading and trailing whitespace removed.||If chars is given and not None, remove characters in chars instead.| | swapcase(self, /)|Convert uppercase characters to lowercase and lowercase characters to uppercase.| | title(self, /)|Return a version of the string where each word is titlecased.||More specifically, words start with uppercased characters and all remaining|cased characters have lower case.| | translate(self, table, /)|Replace each character in the string using the given translation table.|| table|Translation table, which must be a mapping of Unicode ordinals to|Unicode ordinals, strings, or None.||The table must implement lookup/indexing via __getitem__, for instance a|dictionary or list. If this operation raises LookupError, the character is|left untouched. Characters mapped to None are deleted.| | upper(self, /)|Return a copy of the string converted to uppercase.| | zfill(self, width, /)|Pad a numeric string with zeros on the left, to fill a field of the given width.||The string is never truncated.| | ----------------------------------------------------------------------| Static methods defined here:| | __new__(*args, **kwargs) from builtins.type|Create and return a new object. See help(type) for accurate signature.| | maketrans(...)|Return a translation table usable for str.translate().||If there is only one argument, it must be a dictionary mapping Unicode|ordinals (integers) or characters to Unicode ordinals, strings or None.|Character keys will be then converted to ordinals.|If there are two arguments, they must be strings of equal length, and|in the resulting dictionary, each character in x will be mapped to the|character at the same position in y. If there is a third argument, it|must be a string, whose characters will be mapped to None in the result.

2.1.Python字符串处理（去掉空格或者特殊字符 替换操作 查找操作 判断操作 分割合并操作 字符串文档）