邮箱地址匹配. 匹配成功返回(email_name, email_server), 否则返回None

def email_match(string):
    """邮箱地址匹配. 匹配成功返回(email_name, email_server), 否则返回None"""
    m = re.match(email_pattern, string)
    if m:
        # print('Match success: %s' % m.string)
        return m.groups()[0], m.groups()[2]
    else:
        # print('Match failed: %s' % string)
        return None