perl continue next LearningYard学苑分享！带你走进有关Python的知识世界

分享兴趣，传播快乐，增长见闻，留下美好！亲爱的您，这里是学苑。欢迎大家继续访问学苑内容，今天小编为大家带来有关的知识。

Share , , , leave a good! Dear you, here is the . to to visit the of the , today to bring you about

(1)最简单的正则表达式是普通字符事，只能西配自身。

(2)'ython'可以四配'',','

(3)

a-zA-Z0-9

'可以西配一个任意大小写字用或数字。(4)'可以一个四配任意除'a'、'b'、'c'之外的字符。

(5)''或'p(ython|erl)'都可以匹配''或'perl'。

(6)r'(http://)? (wwwl.)? \.org'只他 匹配";、www,和'’.

(7)'*http'只能四配所有以'http‘开头的字符串。

(8)()*:允许模式重复0次或多次。

(9)()+:允许模式重复一次或多次。

(10)()(m,n}:允许模式重复m~n次，注意逗号后面不要有空格。

(11)'(alb)*c':匹配多个(包含0个)a或b,后面紧跟一个字母 c。

(12)’abl1,)':等价于'ab+',匹配以字母a开头后面紧跟一个或多个字母b的字符串。

(13)‘^{1)(

a-zA-Z0-9,_

)(4,19}#39;:匹配长度为5~20的字符串，必须以字母开头并且后面可带数字、字母、“_”“.”的字符串。

(14)'^(\w)(6,20}#39;:匹配长度为6~20的字符串，可以包含字母、数字、下画线。

(15) '^\d{1,3)\.\d(1.3)\.\d(1,3)\\d{1,3)#39;:检查给定字符串是否为合法

(1) The is a thing, which can only match in the west.

(2) ' ython' can be with '', ', '

(3)

A-zA-Z0-9

'can be with a or .(4) ' can be with four other than' a ',' b ',' c '.

(5) '' or 'p (ython | erl)' can match '' or 'perl'.

(6)r'(http://)?(wwwl.)?\. The org 'only he the ";, www, and the ''.

(7) '* http' can only match all with 'http'.

(8) () *: Allow the mode to 0 or more times.

(9) () +: Allow the mode to be once or more times.

(10) () (m, n}: allow the mode to m~n times, note that there is no space the comma.

(11) '(alb) * c': ( 0) a or b, by one c.

(12) 'abl1,)': to 'ab +', a with a b or more by a a.

(13) '^ {1) (

a-zA-Z0-9, _

) (4,19} #39;: A of 5 to 20 must start with a by , , "_"" The of.

(14) '^ (\ w) (6,20} #39;: 6 to 20 , can , , lines.

(15) '^\d{1,3)\. \d(1.3)\. \ d (1,3) \ \ d {1,3) $ ': Check if a given is legal

使用时要注意的是，正则表达式只是进行形式上的检查，并不保证内容一定正确。例如上面的例子中，正则表达式'^\d{1,3}\.\d{1,3}\.\d{1.3)\.\d(1,3)$可以检查字符串是否为IP地址，字符串888.888.888.888这样的也能通过检查，但实际上并不是有效的IP地址。同样的道理，,正则表达式'^\d{18}|\d(15)#39;也只负责检查字符串是否为18位或15位数字,并不保证一定是合法的身份证号。

It be noted that are only and do not that the is . For , in the above, the '^ \ d {1,3} \. \d{1,3}\. \d{1.3)\. \ d (1,3) $ can check if the is an IP , and the 888.888.888.88.888 also it, but it is not a valid IP . In the same way, the '^ \ d {18} | \ d (15) #39; is also for only the is in 18 or 15 , and does not a ID .

the 字符串 is to can or