I'm working on a program that takes the input in a particular format: example "(1,2)(2,3)(4,3)". They are coordinates and there can be infinitely many coordinates "(1,2)(2,3)(4,3)...(a,b)". I'm writing a function "checkFormat(str)" that returns true if the format is satisfied. I've tried writing a function without the use of regex but it proved too difficult. Need help with the regex expression.

CodePudding user response：

Use ^ and $ to match the whole input. in between is one or more set of (...) filled with digits. Assuming coordinates are integer and no extra space in between:

^((\((\d) \,(\d) )\)) $

if /- is allowed and 0 has no sign and could not be extended (00 or 01 not accepted)

^(\(([-\ ]?[1-9]\d*|0)\,(([-\ ]?[1-9]\d*)|0)\)) $

If decimal numbers are included:

^(\(([-\ ]?[1-9]\d*|0)([.]\d )?\,(([-\ ]?[1-9]\d*)|0)([.]\d )?\)) $

To check if the input match or not:

import re
pattern=r'^(\(([-\ ]?[1-9]\d*|0)([.]\d )?\,(([-\ ]?[1-9]\d*)|0)([.]\d )?\)) $'
input='(0,2)(1,2)'
result=bool(re.match(pattern,input))