"urllib.error" --- Exception classes raised by urllib.request ************************************************************* **Source code:** Lib/urllib/error.py ====================================================================== The "urllib.error" module defines the exception classes for exceptions raised by "urllib.request". The base exception class is "URLError". The following exceptions are raised by "urllib.error" as appropriate: exception urllib.error.URLError The handlers raise this exception (or derived exceptions) when they run into a problem. It is a subclass of "OSError". reason The reason for this error. It can be a message string or another exception instance. Changed in version 3.3: "URLError" has been made a subclass of "OSError" instead of "IOError". exception urllib.error.HTTPError Though being an exception (a subclass of "URLError"), an "HTTPError" can also function as a non-exceptional file-like return value (the same thing that "urlopen()" returns). This is useful when handling exotic HTTP errors, such as requests for authentication. code An HTTP status code as defined in **RFC 2616**. This numeric value corresponds to a value found in the dictionary of codes as found in "http.server.BaseHTTPRequestHandler.responses". reason This is usually a string explaining the reason for this error. headers The HTTP response headers for the HTTP request that caused the "HTTPError". New in version 3.4. exception urllib.error.ContentTooShortError(msg, content) This exception is raised when the "urlretrieve()" function detects that the amount of the downloaded data is less than the expected amount (given by the *Content-Length* header). The "content" attribute stores the downloaded (and supposedly truncated) data.