urllib.error --- urllib.request 引发的异常类

源代码： Lib/urllib/error.py

---

The urllib.error module defines the exception classes for exceptions raised by urllib.request. The base exception class is URLError.

下列异常会被 urllib.error 按需引发：

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.

在 3.3 版更改: 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

这通常是一个解释本次错误原因的字符串。

headers

The HTTP response headers for the HTTP request that caused the HTTPError.

3.4 新版功能.

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.