(? i ) caseless (? - i ) cased (? i ) caseless is equivalent to (? i ) caseless (? - i: cased ) caseless. Instead of using two modifiers, one to turn an option on, and one to turn it off, you use a modifier span. The regex (? i ) te (? - i ) st should match test and TEst, but not teST or TEST. You can quickly test how the regex flavor you’re using handles mode modifiers. In all other flavors, the trailing mode modifier either has no effect or is an error. So in Python, (? i ) caseless and caseless (? i ) are both case insensitive. In Python, putting a modifier in the middle of the regex affects the whole regex. If a flavor can’t apply modifiers to only part of the regex then it treats modifiers in the middle of the regex as an error. (? i - s m ) turns on case insensitivity, and turns off both single-line mode and multi-line mode. All modes after the minus sign will be turned off. With these flavors, you can turn off modes by preceding them with a minus sign. If you insert the modifier (? i s m ) in the middle of the regex then the modifier only applies to the part of the regex to the right of the modifier. Modern regex flavors allow you to apply modifiers to only part of the regular expression. Turning Modes On and Off for Only Part of The Regular Expression Only supported by PCRE and languages that use it.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |