匹配数字相关‘.‘ 默认匹配除\n之外的任意一个字符,若指定flag DOTALL,则匹配任意字符,包括换行‘^‘ 匹配字符开头,若指定flags MULTILINE,这种也可以匹配上(r"^a","\nabc\neee",flags=re.MULTILINE)‘$‘ 匹配字符结尾,或e.search("foo$","bfoo\nsdfsf",flags=re.MULTILINE).group()也可以‘*‘ 匹配*号前的字符0次或多次,re.findall("ab*","cabb3abcbbac") 结果为[‘abb‘, ‘ab‘, ‘a‘]‘+‘ 匹配前一个字符1次或多次,re.findall("ab+","ab+cd+abb+bba") 结果[‘ab‘, ‘abb‘]‘?‘ 匹配前一个字符1次或0次‘{m}‘ 匹配前一个字符m次‘{n,m}‘ 匹配前一个字符n到m次,re.findall("ab{1,3}","abb abc abbcbbb") 结果‘abb‘, ‘ab‘, ‘abb‘]‘|‘ 匹配|左或|右的字符,re.search("abc|ABC","ABCBabcCD").group() 结果‘ABC‘‘(...)‘ 分组匹配,re.search("(abc){2}a(123|456)c", "abcabca456c").group() 结果 abcabca456c ‘\A‘ 效果和^是一样的,只从字符开头匹配,re.search("\Aabc","alexabc") 是匹配不到的‘\Z‘ 匹配字符结尾,同$‘\d‘ 匹配数字0-9‘\D‘ 匹配非数字‘\w‘ 匹配[A-Za-z0-9]‘\W‘ 匹配非[A-Za-z0-9]‘s‘ 匹配空白字符、\t、\n、\r , re.search("\s+","ab\tc1\n3").group() 结果 ‘\t‘‘(?P<name>...)‘ 分组匹配 re.search("(?P<province>[0-9]{4})(?P<city>[0-9]{2})(?P<birthday>[0-9]{4})","371481199306143242").groupdict("city") 结果{‘province‘: ‘3714‘, ‘city‘: ‘81‘, ‘birthday‘: ‘1993‘}注意:?P为固定语法格式 注意,re的若干方法:match方法是从字符串开头往后匹配(用的少)例:
res = re.match(‘^Chen‘, ‘Chenronghua123‘) 语法:pattern,stringprint(res)#输出:<_sre.SRE_Match object; span=(0, 4), match=‘Chen‘>
#res = re.match(‘r.+‘, ‘Chen123ronghua123‘) #匹配结果为空,match从字符串开头开始匹配# res = re.search(‘r.+‘, ‘Chen123ronghua123‘) #search 从整个文本中搜索# print(res.group())# 结果:ronghua
常用如下四种:1.search是从整个文本中搜索,匹配到一个就返回2.findall是从整个文本中搜索,贪婪匹配,如果匹配到多个全部返回,findall没有group方法3.split分隔方法4.sub替换方法 仅需轻轻知道的几个匹配模式1.re.I(re.IGNORECASE): 忽略大小写(括号内是完整写法,下同)2.M(MULTILINE): 多行模式,改变‘^‘和‘$‘的行为(参见上图) [用得很少]3.S(DOTALL): 点任意匹配模式,改变‘.‘的行为 split方法:res = re.split(‘[0-9]+‘, ‘abc12de3f45GH‘)print(res)输出:[‘abc‘, ‘de‘, ‘f‘, ‘GH‘] sub方法:res = re.sub(‘[0-9]+‘, ‘|‘, ‘abc12de3f45GH‘, count=2)print(res)输出:abc|de|f45GH 1.re.I(re.IGNORECASE): 忽略大小写res = re.search(‘[a-z]+‘, ‘abcGH‘, flags=re.I)print(res.group())输出:abcGH 2.M(MULTILINE): 多行模式,改变‘^‘和‘$‘的行为res = re.search(r"^a", "\nabc\neee", flags=re.M)print(res.group())输出:a 3.S(DOTALL): 点任意匹配模式,改变‘.‘的行为res = re.search(".+", "\nabc\neee", flags=re.S)print(res.group())输出:a 举例:‘.‘ 默认匹配除\n之外的任意一个字符,若指定flag DOTALL,则匹配任意字符,包括换行 res = re.match(‘.+‘, ‘Chen123ronghua123‘)print(res.group())输出:Chen123ronghua123 ‘$‘ 匹配字符结尾,或e.search("foo$","bfoo\nsdfsf",flags=re.MULTILINE).group()也可以 res = re.match(‘r.+‘, ‘Chen123ronghua123‘) #匹配结果为空,match从字符串开头开始匹配res = re.search(‘r.+‘, ‘Chen123ronghua123‘) #search 从整个文本中搜索print(res.group())结果:ronghua ‘+‘ 匹配前一个字符1次或多次,re.findall("ab+","ab+cd+abb+bba") 结果[‘ab‘, ‘abb‘]res = re.search(‘r[a-z]+a‘, ‘Chen123ronghua123‘) #匹配ronghuaprint(res.group())结果:ronghua res = re.search(‘#.+#‘, ‘1123#hello#‘)print(res.group())结果:#hello# ‘?‘ 匹配前一个字符1次或0次res0 = re.search(‘aal?‘, ‘aalex‘)res1 = re.search(‘aal?‘, ‘aaex‘)print(res0.group())print(res1.group())输出aalaa ‘{m}‘ 匹配前一个字符m次res = re.search(‘[0-9]{3}‘, ‘aa1xe2pp345lex‘) #匹配前面的数字三次print(res.group()) ‘{n,m}‘ 匹配前一个字符n到m次res = re.search(‘[0-9]{1,3}‘, ‘aa1xe2pp345lex‘) #匹配前面的数字1到3次print(res.group())输出 1 findall 贪婪匹配res = re.findall(‘[0-9]{1,3}‘, ‘aa1xe2pp345lex‘) #findall,贪婪匹配,匹配前面的数字1到3次print(res)输出[‘1‘, ‘2‘, ‘345‘] #以列表的形式返回 ‘|‘ 匹配|左或|右的字符,re.search("abc|ABC","ABCBabcCD").group() 结果‘ABC‘ res = re.search(‘abc|ABC‘, ‘ABCBabcCD‘)print(res.group())输出 ABC res = re.findall(‘abc|ABC‘, ‘ABCBabcCD‘)print(res)输出 [‘ABC‘, ‘abc‘] ‘(...)‘ 分组匹配,re.search("(abc){2}a(123|456)c", "abcabca456c").group() 结果 abcabca456c res = re.search(‘(abc){2}‘, ‘alexabcabc‘)print(res.group())输出 abcabc res = re.search(‘(abc){2}(\|\|=){2}‘, ‘alexabcabc||=||=‘) 匹配||= 两次,注意需要转义print(res.group())输出:abcabc||=||= ‘\D‘ 匹配非数字res = re.search(‘\D+‘, ‘123$- a‘)print(res.group())输出:$- a ‘\w‘ 匹配[A-Za-z0-9] 除了特殊字符都匹配 res = re.search(‘\w+‘, ‘123$- a‘)print(res.group())输出:123 ‘\W‘ 匹配非[A-Za-z0-9] 只匹配特殊字符res = re.search(‘\W+‘, ‘123$- ...a‘)print(res.group())输出:$- ... ‘\s‘ 匹配空白字符、\t、\n、\r , re.search("\s+","ab\tc1\n3").group() 结果 ‘\t‘res = re.findall(‘\s‘, ‘123$- \r\n\t...a‘)print(res)输出:[‘ ‘, ‘\r‘, ‘\n‘, ‘\t‘] >>> re.search(‘\s+‘, ‘123$- \r\n‘)<_sre.SRE_Match object; span=(5, 9), match=‘ \t\r\n‘> ‘\A‘ 效果和^是一样的,只从字符开头匹配,re.search("\Aabc","alexabc") 是匹配不到的‘\Z‘ 匹配字符结尾,同$‘\d‘ 匹配数字0-9 例:res = re.search(‘\A[0-9]+[a-z]\Z‘, ‘123a‘)print(res.group())输出:123a * : 0个至多个+ :1个至多个 res = re.match(‘^Chen\d+‘, ‘Chen123ronghua123‘)print(res)print(res.group()) #查看匹配到的对象 输出:<_sre.SRE_Match object; span=(0, 7), match=‘Chen123‘>Chen123 ‘(?P<name>...)‘ 分组匹配res = re.search("(?P<province>[0-9]{4})(?P<city>[0-9]{2})(?P<birthday>[0-9]{4})","371481199306143242").groupdict("city")print(res)结果{‘province‘: ‘3714‘, ‘city‘: ‘81‘, ‘birthday‘: ‘1993‘}
时间: 2024-08-05 07:07:09