1 """Exception classes raised by urllib. 2 3 The base exception class is URLError, which inherits from OSError. It 4 doesn't define any behavior of its own, but is the base class for all 5 exceptions defined in this package. 6 7 HTTPError is an exception class that is also a valid HTTP response 8 instance. It behaves this way because HTTP protocol errors are valid 9 responses, with a status code, headers, and a body. In some contexts, 10 an application may want to handle an exception like a regular 11 response. 12 """ 13 14 import urllib.response 15 16 __all__ = ['URLError', 'HTTPError', 'ContentTooShortError'] 17 18 19 # do these error classes make sense? 20 # make sure all of the OSError stuff is overridden. we just want to be 21 # subtypes. 22 23 class URLError(OSError): 24 # URLError is a sub-type of OSError, but it doesn't share any of 25 # the implementation. need to override __init__ and __str__. 26 # It sets self.args for compatibility with other EnvironmentError 27 # subclasses, but args doesn't have the typical format with errno in 28 # slot 0 and strerror in slot 1. This may be better than nothing. 29 def __init__(self, reason, filename=None): 30 self.args = reason, 31 self.reason = reason 32 if filename is not None: 33 self.filename = filename 34 35 def __str__(self): 36 return '<urlopen error %s>' % self.reason 37 38 39 class HTTPError(URLError, urllib.response.addinfourl): 40 """Raised when HTTP error occurs, but also acts like non-error return""" 41 __super_init = urllib.response.addinfourl.__init__ 42 43 def __init__(self, url, code, msg, hdrs, fp): 44 self.code = code 45 self.msg = msg 46 self.hdrs = hdrs 47 self.fp = fp 48 self.filename = url 49 # The addinfourl classes depend on fp being a valid file 50 # object. In some cases, the HTTPError may not have a valid 51 # file object. If this happens, the simplest workaround is to 52 # not initialize the base classes. 53 if fp is not None: 54 self.__super_init(fp, hdrs, url, code) 55 56 def __str__(self): 57 return 'HTTP Error %s: %s' % (self.code, self.msg) 58 59 def __repr__(self): 60 return '<HTTPError %s: %r>' % (self.code, self.msg) 61 62 # since URLError specifies a .reason attribute, HTTPError should also 63 # provide this attribute. See issue13211 for discussion. 64 @property 65 def reason(self): 66 return self.msg 67 68 @property 69 def headers(self): 70 return self.hdrs 71 72 @headers.setter 73 def headers(self, headers): 74 self.hdrs = headers 75 76 77 class ContentTooShortError(URLError): 78 """Exception raised when downloaded size does not match content-length.""" 79 def __init__(self, message, content): 80 URLError.__init__(self, message) 81 self.content = content 82
