Commonly used matching rules
Match characters
| symbol | Matching rules |
|---|---|
| . | Match any 1 character, except for newline characters\n |
| [ ] | This is a set that matches any character in [] |
| \d | Match a number, that is, 0-9 |
| \D | Match non-digits, i.e. not digits |
| \s | Match blank, that is, space, tab key |
| \S | Match non-blank |
| \w | Match word characters, namely az, AZ, 0-9 |
| \W | Match non-word characters |
| * | Match the previous character 0 or countless times, it can be dispensable |
| + | Match the previous character appears 1 time or countless times, that is, at least 1 time |
| \ ? | Match the previous character 1 or 0 times, that is, either once or not |
| {m} | Match the previous character m times |
| {m,} | Match the previous character at least m times |
| {n,m} | Match the previous character from n to m times |
| ^ | Match the beginning of the string |
| $ | Match end of string |
Group matching
| symbol | Matching rules |
|---|---|
| （） | Treat the characters in brackets as a group |
| \on one | num can be 1, 2, 3,..., the reference group matches the string |
| （？P） | Group aliases |
| （？P=name） | Quote the string matched by the name group by alias |
Supplement: |: Match any expression on the left and right
Modifier
| Modifier | description |
|---|---|
| re.I | When matching, ignore the case of letters |
| re.L | Do local-aware matching |
| re.M | Multi-line matching, affects ^ and $ |
| re.S | When matching, all characters including newline |
| re.U | Parse characters according to the Unicode character set |
| re.X | This flag gives you a more flexible format so that you can write regular expressions easier to understand |
For more details, please refer to: regular expression