^ matches position just before the first character of the string $ matches position just after the last character of the string . matches a single character. Does not matter what character it is, except newline * matches preceding match zero or more times So, ^.*$ means – match, from beginning to end, any character that appears zero or more times. … Read more
The non-greedy ? works perfectly fine. It’s just that you need to select dot matches all option in the regex engines (regexpal, the engine you used, also has this option) you are testing with. This is because, regex engines generally don’t match line breaks when you use .. You need to tell them explicitly that you want to match line-breaks … Read more
re.split is expected to be slower, as the usage of regular expressions incurs some overhead. Of course if you are splitting on a constant string, there is no point in using re.split().
You can use negated character classes to exclude certain characters: for example [^abcde] will match anything but a,b,c,d,e characters. Instead of specifying all the characters literally, you can use shorthands inside character classes: [\w] (lowercase) will match any “word character” (letter, numbers and underscore), [\W] (uppercase) will match anything but word characters; similarly, [\d] will match the 0-9 digits while [\D] matches anything but the 0-9 digits, … Read more
There is the W3C DOM 3 Core textContent property supported by some browsers, or the MS/HTML5 innerText property supported by other browsers (some support both). Likely the content of the script element is unwanted, so a recursive traverse of the related part of the DOM tree seems best:
You could use the in keyword to check for your substring: Or, if you had a string s with \n characters: Your regex only prints elephant because that’s what it captured: exactly your regex string. If you were to try the following regex instead: Then you’d have results for test.group(0) and test.group(1) which include the whole line before and after the elephants. That’s the whole captured string. … Read more
A great way to do this is to use negative lookahead: The negative lookahead construct is the pair of parentheses, with the opening parenthesis followed by a question mark and an exclamation point. Inside the lookahead [is any regex pattern].
The key to getting this to work is to tell sed to exclude what you don’t want to be output as well as specifying what you do want. This says: don’t default to printing each line (-n) exclude zero or more non-digits include one or more digits exclude one or more non-digits include one or more digits … Read more
This first removes all non-letter characters, folds to lowercase, then splits the input, doing all the work in a single line: Spaces are initially left in the input so the split will still work. By removing the rubbish characters before splitting, you avoid having to loop through the elements.