Python Connection Error
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a try statement with an except clause that mentions a particular class, that clause also handles any exception classes derived from that class (but
Valueerror Python
not exception classes from which it is derived). Two exception classes that are python custom exception not related via subclassing are never equivalent, even if they have the same name. The built-in exceptions listed below
Python Valueerror Example
can be generated by the interpreter or built-in functions. Except where mentioned, they have an "associated value" indicating the detailed cause of the error. This may be a string or a python requests connectionerror tuple of several items of information (e.g., an error code and a string explaining the code). The associated value is usually passed as arguments to the exception class's constructor. User code can raise built-in exceptions. This can be used to test an exception handler or to report an error condition "just like" the situation in which the interpreter raises the same exception; but beware python filenotfounderror that there is nothing to prevent user code from raising an inappropriate error. The built-in exception classes can be subclassed to define new exceptions; programmers are encouraged to derive new exceptions from the Exception class or one of its subclasses, and not from BaseException. More information on defining exceptions is available in the Python Tutorial under User-defined Exceptions. When raising (or re-raising) an exception in an except or finally clause __context__ is automatically set to the last exception caught; if the new exception is not handled the traceback that is eventually displayed will include the originating exception(s) and the final exception. When raising a new exception (rather than using a bare raise to re-raise the exception currently being handled), the implicit exception context can be supplemented with an explicit cause by using from with raise: raise new_exc from original_exc The expression following from must be an exception or None. It will be set as __cause__ on the raised exception. Setting __cause__ also implicitly sets the __suppress_context__ attribute to True, so that using here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack python exception class methods Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; https://docs.python.org/3/library/exceptions.html it only takes a minute: Sign up raise ConnectionError in python2.7 up vote 1 down vote favorite i want to raise ConnectionError (a python 3 subclass) when my program fails to connect to a local service. i'm using python2.7. testing this out though, it looks like i have to import a module to get this working: >>> raise ConnectionError("test") Traceback http://stackoverflow.com/questions/31354166/raise-connectionerror-in-python2-7 (most recent call last): File " """There was an ambiguous exception that occurred while handling your request. """ def __init__(self, http://docs.python-requests.org/en/master/_modules/requests/exceptions/ *args, **kwargs): """Initialize RequestException with `request` and `response` http://www.programcreek.com/python/example/50847/requests.exceptions.ConnectionError objects.""" response = kwargs.pop('response', None) self.response = response self.request = kwargs.pop('request', None) if (response is not None and not self.request and hasattr(response, 'request')): self.request = self.response.request super(RequestException, self).__init__(*args, **kwargs) [docs]class HTTPError(RequestException): """An HTTP python exception error occurred.""" [docs]class ConnectionError(RequestException): """A Connection error occurred.""" class ProxyError(ConnectionError): """A proxy error occurred.""" class SSLError(ConnectionError): """An SSL error occurred.""" [docs]class Timeout(RequestException): """The request timed out. Catching this error will catch both :exc:`~requests.exceptions.ConnectTimeout` and :exc:`~requests.exceptions.ReadTimeout` errors. """ [docs]class ConnectTimeout(ConnectionError, Timeout): """The request python connection error timed out while trying to connect to the remote server. Requests that produced this error are safe to retry. """ [docs]class ReadTimeout(Timeout): """The server did not send any data in the allotted amount of time.""" [docs]class URLRequired(RequestException): """A valid URL is required to make a request.""" [docs]class TooManyRedirects(RequestException): """Too many redirects.""" class MissingSchema(RequestException, ValueError): """The URL schema (e.g. http or https) is missing.""" class InvalidSchema(RequestException, ValueError): """See defaults.py for valid schemas.""" class InvalidURL(RequestException, ValueError): """The URL provided was somehow invalid.""" class InvalidHeader(RequestException, ValueError): """The header value provided was somehow invalid.""" class ChunkedEncodingError(RequestException): """The server declared chunked encoding but sent an invalid chunk.""" class ContentDecodingError(RequestException, BaseHTTPError): """Failed to decode response content""" class StreamConsumedError(RequestException, TypeError): """The content for this response was already consumed""" class RetryError(Reques projects. You can click to vote up the examples you like, or click to vote down the exmaples you don't like. Your votes will be used in our system to extract more high-quality examples. You may also check out all available functions/classes of the module requests.exceptions , or try the search function . Example 1 From project nyantip, under directory src/ctb, in source file ctb_misc.py. Score: 25 def praw_call(prawFunc, *extraArgs, **extraKwArgs): """ Call prawFunc() with extraArgs and extraKwArgs Retry if Reddit is down """ while True: try: res = prawFunc(*extraArgs, **extraKwArgs) return res except (HTTPError, ConnectionError, Timeout, RateLimitExceeded, timeout) as e: if str(e) == "403 Client Error: Forbidden": lg.warning("praw_call(): 403 forbidden") return False if str(e) == "404 Client Error: Not Found": lg.warning("praw_call(): 404 not found") return False lg.warning("praw_call(): Reddit is down (%s), sleeping...", e) time.sleep(30) pass except Exception as e: raise return True Example 2 From project city_mood-master, under directory , in source file city_mood.py. Score: 13 def post_mood(): os.chdir(DIR) mood = get_mood() if not os.path.isfile('old_mood.txt'): with open('old_mood.txt','w') as f: f.write('') with open('old_mood.txt','r') as f: old_mood = f.read() if mood != old_mood: with open('old_mood.txt','w') as f: f.write(mood) data = {'status':'Berkeley is currently feeling ' + mood} try: r = TWITTER.post(url=POST_URL,data=data) if r == 401: #if authorization fails logging.error(r.reason) if r == 403: # if forbidden logging.error(r.reason) except ConnectionError: time.sleep(120) r = TWITTER.post(url=POST_URL,data=data) except Timeout: time.sleep(120) r = TWITTER.post(url=POST_URL,data=data) else: pass Example 3 From project MesoPy-master, under directory , in source file MesoPy.py. Score: 10 def _get_response(self, endpoint, request_dict): """ Returns a dictionary of data requested by each function. Arguments: ---------- endpoint: string, mandatory Set in all other methods, this is the API endpoint specific to each method. request_dict: string, mandatory A dictionary of parameters that are formatted into the API call. Returns: response: A dictionary that has been dumped from JSON. Raises: MesoPyError: Overrides the exceptions given in the requests library to give more custom error messages. Connection_error occurs if no internet connection exists. Timeout_error occurs if the request takes too lPython Exception Message
Python Programming Can Handle Every Error Implicitly A) True B) False