python - repetition "{}" on fly for regex -

i trying write function compare value regex see if matches. problem have quite many regex similar 1 difference range {} e.g. ^[a-z]{0,500}$ & ^[a-z]{0,200}$ similar regex diff of range/repetition. trying solve problem of how deal these regex 1 function. far have written function. think there must option better have done below. should able deal if no max or min specified well.

def check(value, min=none, max=none):     regex = "^[a-z]"+"{"+min+","+max+"}$"     r= re.compile(regex)     if r.match(value):         return true     else:        return false 

use min="0" , max="" instead (that way, construct valid ranges if left unspecified).

also, don't if condition: return true etc. - return match object - evaluate true if there match (and can stuff later if want to).

further, no need compile regex if you're using once.

def check(value, min="0", max=""):     regex = "[a-z]{" + min + "," + max + "}$"     return re.match(regex, value) 

also, i've removed ^ because it's implicit in re.match().