def isValidHostname(hostname):

    if len(hostname) > 255:
        return False
    if hostname[-1:] == ".":
        hostname = hostname[:-1]   # strip exactly one dot from the right,
                                   #  if present
    allowed = re.compile("(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
    return all(allowed.match(x) for x in hostname.split("."))

AddressRegex = "^(ftp|http|https):\/\/([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}:[0-9]{1,5})$";

HostnameRegex =  /^(ftp|http|https):\/\/([a-z0-9]+\.)?[a-z0-9][a-z0-9-]*((\.[a-z]{2,6})|(\.[a-z]{2,6})(\.[a-z]{2,6}))$/i

这些re仅用于此类型验证

只在以下情况下工作 http://www.kk.com http://www.kk.co.in

不适合

http://www.kk.com/ http://www.kk.co.in.kk

http://www.kk.com/dfas http://www.kk.co.in/

def isValidHostname(hostname):

    if len(hostname) > 255:
        return False
    if hostname[-1:] == ".":
        hostname = hostname[:-1]   # strip exactly one dot from the right,
                                   #  if present
    allowed = re.compile("(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
    return all(allowed.match(x) for x in hostname.split("."))

这适用于有效的IP地址:

regex = '^([0-9]|[1-9][0-9]|[1][0-9][0-9]|[2][0-5][0-5])[.]([0-9]|[1-9][0-9]|[1][0-9][0-9]|[2][0-5][0-5])[.]([0-9]|[1-9][0-9]|[1][0-9][0-9]|[2][0-5][0-5])[.]([0-9]|[1-9][0-9]|[1][0-9][0-9]|[2][0-5][0-5])$'

>>> my_hostname = "testhostn.ame"
>>> print bool(re.match("^(([a-zA-Z]|[a-zA-Z][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])$", my_hostname))
True
>>> my_hostname = "testhostn....ame"
>>> print bool(re.match("^(([a-zA-Z]|[a-zA-Z][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])$", my_hostname))
False
>>> my_hostname = "testhostn.A.ame"
>>> print bool(re.match("^(([a-zA-Z]|[a-zA-Z][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])$", my_hostname))
True

我发现这对于IP地址来说非常有效。它像上面的答案一样进行验证，但它也确保ip是隔离的，因此在ip之后或之前没有文本或更多的数字/小数。

(? < ! \ S)(吗? (?:\ d | (1 - 9) \ d | 1 \ \ d | 2 (0 - 4) \ d | 25 (0 - 5)) \ b |。\ b) {7} (? ! \ S)