HTTP連接解析失敗

Question

我試圖呼叫connect()函數parse_ip()，它將通過網頁搜索輸入IP來查找匹配項。對列表THREAT的每個元素調用 Connect函數。 這裏是我的代碼：

def connect(url): 
    sessions = requests.Session() 
    print "Connecting with", url 
    try: 
     r = sessions.get(url, 
         headers = create_basic_headers(), 
         proxies = {'http': HTTP_PROXY, 'https': HTTPS_PROXY}) 
     return r 
    except: 
     sys.stdout.write('[!] Could not connect to: %s\n' % url) 

def parse(ip): 
    counter = 0 
    ioc_list = [] 
    for filename, source in THREAT.iteritems(): 
     c = connect(source) 
     for line in c: 
      if line.startswith("/") or line.startswith('\n') or line.startswith("#"): 
       pass 
      else: 
       counter += 1 
       d = 0 
       while d < len(ip): 
        if ip[d] in line: 
         print ip[d], source 

        d +=1 

在運行腳本，解析頁面連接失敗和atlast我收到以下錯誤：

[!] Could not connect to: http://... for line in c: TypeError: 'NoneType' object is not iterable

誰能幫我在盤算什麼錯誤在這。

Answer 1

requests無法建立到服務器的連接。引發異常，然後在裸除外條款中處理。沒有關於例外的信息顯示，所以很難診斷實際的連接問題。

在例外connect()返回None給調用者，然後嘗試遍歷它。這是導致TypeError的原因。

爲什麼不嘗試打印異常？

def connect(url): 
    sessions = requests.Session() 
    print "Connecting with", url 
    try: 
     r = sessions.get(url, 
         headers = create_basic_headers(), 
         proxies = {'http': HTTP_PROXY, 'https': HTTPS_PROXY}) 
     return r 
    except requests.exceptions.ConnectionError as exc: 
     sys.stdout.write('[!] Could not connect to: %s\n' % url) 
     sys.stdout.write('Exception: %s' % exc) 

希望這會告訴你爲什麼連接失敗。

之後，您需要檢查返回值connect()在parse()。喜歡的東西：

c = connect(source) 
if c is not None: 
    for line in c: 
     .... 

另外，您可以在connect()重新拋出異常，讓parse()處理。