求重构：获取一个服务器HTTP状态

get_http_status.py

def get_http_status(ip, port, host, path='/',ssl=False): 
    '''
    根据指定IP，端口等信息返回该服务器的http状态，应答码，错误原因，响应时间
    代码写的很难看，求重构
    '''
    newstatus, status_code, status_desc = config.Unknow, -99, '未知状态'
    starttime = datetime.now()

    try:        
        status_code = int(http((ip, port),host, path, ssl))

        perfmon.ok_sum.increase()
        perfmon.ok_rate.increase()

        if status_code / 100 in (2,3):
            newstatus   = config.Ok
            status_desc = '正常'
        elif status_code >= 500:
            newstatus   = config.Down
            status_desc = '服务器端错误'
        else:
            newstatus   = config.Warn
            status_desc = '服务器返回%s错误' % (status_code,)
    except Exception, ex:
        if isinstance(ex, socket.error):
            if isinstance(ex, socket.timeout):
                status_code = -3
                status_desc = ex.message
            else:
                status_code = -1
                status_desc = ex.strerror
        elif isinstance(ex, ValueError):
            status_code = -8
            status_desc = '服务器返回无效HTTP应答' 
        else:
            status_code = -2
            status_desc = '未知错误'

        newstatus = config.Down 

        perfmon.error_sum.increase()
        perfmon.error_rate.increase()
        logging.debug("http error:%s-%s", ip ,ex)

    responsetime = (datetime.now()-starttime).microseconds/1000
    return responsetime, newstatus, status_code, status_desc

第一次重构

def get_http_status(ip, port, host, path='/',ssl=False):
    def increase_ok_perfmon_counter():
        perfmon.ok_sum.increase()
        perfmon.ok_rate.increase()

    def increase_error_perfmon_counter():
        perfmon.error_sum.increase()
        perfmon.error_rate.increase()

    def calc_newstatus_and_status_desc_from_status_code(status_code):
        if status_code / 100 in (2,3):
            return  config.Ok,'正常'
        if status_code >= 500:
            return config.Down, '服务器端错误'
        return config.Warn, '服务器返回%s错误' % (status_code,)

    def calc_status_code_and_newstatus_from_socket_error(ex):
        if isinstance(ex, socket.timeout):
            return  -3, ex.message
        return -1, ex.strerror

    def calc_status_code_and_status_desc_from_error(ex):
        if isinstance(ex, socket.error):
            return calc_status_code_and_newstatus_from_socket_error(ex)
        if isinstance(ex, ValueError):
            return  -8, '服务器返回无效HTTP应答'
        return  -2, '未知错误'

    def error_handler(ex):
        increase_error_perfmon_counter
        logging.debug("http error:%s-%s", ip ,ex)
        status_code, status_desc = calc_status_code_and_status_desc_from_error(ex)
        return config.Down, status_code, status_desc

    newstatus, status_code, status_desc = config.Unknow, -99, '未知状态'
    starttime = datetime.now()
    try:
        status_code = int(http((ip, port),host, path, ssl))
        newstatus, status_desc = calc_newstatus_and_status_desc_from_status_code(status_code)
        increase_ok_perfmon_counter()
    except Exception, ex:
        newstatus, status_code, status_desc = error_handler(ex)
    responsetime = (datetime.now()-starttime).microseconds/1000
    return responsetime, newstatus, status_code, status_desc

这一次的重构还有什么不满意的地方？

我不知道最后10行再怎么写的简洁易懂一些。

newstatus, status_code, status_desc = config.Unknow, -99, '未知状态'

这个写法可读性不高啊，而且后期维护起来，比如加个新变量什么的也不方便