正则表达式匹配包含空格但不能全部为空格的数字？

Question

i'm writing a python regex code to test if a string may be numbers. i wrote follows:

import regex as re
re.match('(([-\s]*)([\d\s,]+)(\.?)([\d\s]*)(%?))',' - 1, 00 0.0 0 %')

this one works. but how to make this example string( '.01' or .01 ) not matched? ie how to make the pattern matches the string that contains any digits, , , . ,space and % , but not matches the one that contents before . are only spaces or nothing.

Answer 1

Just add a lookahead (?=[\\s,]*\\d) before matching the digits before the . , asserting that there is a digit (before the . ):

(([-\s]*)(?=[\s,]*\d)([\d\s,]+)(\.?)([\d\s]*)(%?))