python requests异常处理

requests的所有异常归类：

IOError	RequestException	HTTPError(RequestException)
		UnrewindableBodyError(RequestException)
		RetryError(RequestException)
		ConnectionError(RequestException)	ProxyError(ConnectionError)
			SSLError(ConnectionError)
			ConnectTimeout(ConnectionError, Timeout)
		Timeout(RequestException)	ReadTimeout
		URLRequired(RequestException)
		TooManyRedirects(RequestException)
		MissingSchema(RequestException, ValueError)
		InvalidSchema(RequestException,ValueError)
		InvalidURL(RequestException,ValueError)
		InvalidHeader(RequestException,ValueError)
		ChunkedEncodingError(RequestException)
		StreamConsumedError(RequestException,TypeError)
		ContentDecodingError(RequestException,BaseHTTPError)
	RequestsWarning(Warning)	FileModeWarning(RequestsWarning, DeprecationWarning)

[docs]class RequestException(IOError):

"There was an ambiguous exception that occurred while handling your request."

class HTTPError ( RequestException ): """An HTTP 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. """

class ConnectTimeout(ConnectionError, Timeout): 

[docs]\

  """The request 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 InvalidProxyURL(InvalidURL): 

"""The proxy URL provided is 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(RequestException): 

"""Custom retries logic failed"""

class UnrewindableBodyError(RequestException): 

"""Requests encountered an error when trying to rewind a body"""

# Warnings

class RequestsWarning(Warning): 

"""Base warning for Requests.""" 

pass

class FileModeWarning(RequestsWarning, DeprecationWarning): 

"""A file was opened in text mode, but Requests determined its binary length.""" 

pass

class RequestsDependencyWarning(RequestsWarning): 

"""An imported dependency doesn't match the expected version range.""" 

pass