I am new to Python regex and am trying to match non-white space ASCII characters in Python.
The following is my code:
impore re p = re.compile(r"[\S]{2,3}", re.ASCII) p.search('1234') # have some result p.search('你好吗') # also have result, but Why? I have specified ASCII mode in re.compile, but p.search('你好吗') still have result. I wonder what I am doing wrong here?
The re.A flag only affects what shorthand character classes match.
In Python 3.x, shorthand character classes are Unicode aware, the Python 2.x re.UNICODE/re.U is ON by default. That means:
\d: Matches any Unicode decimal digit (that is, any character in Unicode character category [Nd])\D: Matches any character which is not a decimal digit. (So, all characters other than those in the Nd Unicode category).\w - Matches Unicode word characters; this includes most characters that can be part of a word in any language, as well as numbers and the underscore. (So, \w+ matches each word in a My name is Виктор string)\W - Matches any character which is not a word character. This is the opposite of \w. (So, it will not match any Unicode letter or digit.)\s - Matches Unicode whitespace characters (it will match NEL, hard spaces, etc.)\S - Matches any character which is not a whitespace character. (So, no match for NEL, hard space, etc.)\b - word boundaries match locations between Unicode letters/digits and non-letters/digits or start/end of string.\B - non-word boundaries match locations between two Unicode letters/digits, two non-letters/digits or between a Unicode non-letter/digit and start/end of string.If you want to disable this behavior, you use re.A or re.ASCII:
Make
\w,\W,\b,\B,\d,\D,\sand\Sperform ASCII-only matching instead of full Unicode matching. This is only meaningful for Unicode patterns, and is ignored for byte patterns. Corresponds to the inline flag(?a).
That means that:
\d = [0-9] - and no longer matches Hindi, Bengali, etc. digits\D = [^0-9] - and matches any characters other than ASCII digits (i.e. it acts as (?u)(?![0-9])\d now)\w = [A-Za-z0-9_] - and it only matches ASCII words now, Wiktor is matched with \w+, but Виктор does not\W = [^A-Za-z0-9_] - it matches any char but ASCII letters/digits/_ (i.e. it matches 你好吗, Виктор, etc.\s = [ \t\n\r\f\v] - matches a regular space, tab, linefeed, carriage return, form feed and a vertical tab\S = [^ \t\n\r\f\v] - matches any char other than a space, tab, linefeed, carriage return, form feed and a vertical tab, so it matches all Unicode letters, digits and punctuation and Unicode (non-ASCII) whitespace. E.g., re.sub(r'\S+', r'{\g<0>}', '\xA0 ', flags=re.A) will return '{ } ', as you see, the \S now matches hard spaces.
\urefer this stackoverflow.com/questions/393843/…[^ \t\n\r\f\v]. So unicode characters should match. Thanks!!!