Day of the Python regular expression

Tag: expression returns the specified any regular module digital print class

Re module \ Regular expression one, meta-character

1,. ^ $ * + ? { } [ ] | ( ) \

"."　　Represents (any one character) "*" for (any number of arbitrary characters, 0-Infinity) "+" stands for (any one or no number, 1-infinity) "?" Represents (0 or 1 characters) "^" for (beginning of String) "$" for (end of String) "{}" representation (specified number of times)

2. Escape character \

1), backslash followed by meta-character removal of special functions, such as \.

2), back slash behind with ordinary characters to achieve special functions, such as \d

\d  matches any decimal number;      it is equivalent to class [0-9]. \d  matches any non-numeric character;    it is equivalent to class [^0-9]. \s  matches any whitespace character;      it is equivalent to class [\t\n\r\f\v]. \s  matches any non-whitespace character;    it is equivalent to class [^ \t\n\r\f\v]. \w  matches any alphanumeric character;   it is equivalent to class [a-za-z0-9_]. \w  matches any non-alphanumeric character; it is equivalent to a class [^a-za-z0-9_]\b  matches a special character boundary, such as a space, &,#, etc.

3. Group ()

ret = Re.findall ("(yuan) +", "Lalal11yuanhao22yuanyuanhaohao33yuan") #分组 (), returned with the FindAll command is a grouped content print (ret) #[' yuan ', ' Yuan ', ' yuan ']

　　

Day of the Python regular expression