网站建设征求意见表,服务哪家好中医小程序定制,jsp网站访问万维网,汕头公司建站模板正则表达式特殊字符序列#xff0c;匹配检索和替换文本普通字符 特殊字符 数量#xff0c;普通字符用来定边界更改字符思路字符串函数 正则 for循环元字符 匹配一个字符# 元字符大写#xff0c;一般都是取小写的反1. 0~9 整数 \d …正则表达式特殊字符序列匹配检索和替换文本普通字符 特殊字符 数量普通字符用来定边界更改字符思路字符串函数 正则 for循环元字符 匹配一个字符# 元字符大写一般都是取小写的反1. 0~9 整数 \d 取反 \Dimport reexample_str Beautiful is better than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r\d, example_str))print(re.findall(r\D, example_str))2. 字母、数字、下划线 \w 取反 \Wimport reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r‘\w‘, example_str))print(re.findall(r‘\W‘, example_str))3. 空白字符(空格、\t、\t、\n) \s 取反 \Simport reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r‘\s‘, example_str))print(re.findall(r‘\S‘, example_str))4. 字符集中出现任意一个 [] 0-9 a-z A-Z 取反 [^]import reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r‘[0-9]‘, example_str))print(re.findall(r‘[^0-9]‘, example_str))5. 除 \n 之外任意字符import reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r., example_str))数量词 指定前面一个字符出现次数1. 贪婪和非贪婪a. 默认情况下是贪婪匹配尽可能最大匹配直至某个字符不满足条件才会停止(最大满足匹配)b. 非贪婪匹配 在数量词后面加上 ? 最小满足匹配c. 贪婪和非贪婪的使用是程序引起bug重大原因import reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r‘.*u‘, example_str))print(re.findall(r‘.*?u‘, example_str))2. 重复指定次数 {n} {n, m}import reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r‘\d{3}‘, example_str))3. 0次和无限多次 *import reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r‘.*‘, example_str))4. 1次和无限多次 import reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r‘\d‘, example_str))5. 0次或1次 ? 使用思路: 去重import reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r‘7896?‘, example_str))边界匹配1. 从字符串开头匹配 ^2. 从字符串结尾匹配 $正则表达式或关系 |满足 | 左边或者右边的正则表达式import reexample_str Beautiful is better_ than ugly 78966828 $ \r \r\n ^Explicit is better than implicitprint(re.findall(r‘\d|\w‘, example_str))组() 括号内的正则表达式当作单个字符并且返回()内正则匹配的内容可以多个与关系Python-正则相关模块-re1. 从字符中找到匹配正则的字符 findall()import rename Hello Python 3.7, 123456789total re.findall(r\d, name)print(total)2. 替换正则匹配者字符串 sub()import redef replace(value):return str(int(value.group()) 1)result_str re.sub(r\d, replace, name, 0)print(result_str)匹配一个中文字符 [\u4E00-\u9FA5]
