如下是django中做url验证的正则表达式：
1 regex = re.compile( 2 r'^(?:http|ftp)s?://' # http:// or https:// 3 r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?.)+(?:[A-Z]{2,6}.?|[A-Z0-9-]{2,}.?)|' #domain... 4 r'localhost|' #localhost... 5 r'd{1,3}.d{1,3}.d{1,3}.d{1,3})' # ...or ip 6 r'(?::d+)?' # optional port 7 r'(?:/?|[/?]S+)$', re.IGNORECASE)