email.errors: 异常和缺陷类

源代码: Lib/email/errors.py

以下异常类在 email.errors 模块中定义：

exception email.errors.MessageError

这是 email 包可以引发的所有异常的基类。 它源自标准异常 Exception 类，这个类没有定义其他方法。

exception email.errors.MessageParseError

这是由 Parser 类引发的异常的基类。它派生自 MessageError。 headerregistry 使用的解析器也在内部使用这个类。

exception email.errors.HeaderParseError

在解析消息的 RFC 5322 标头时，某些错误条件下会触发，此类派生自 MessageParseError。 如果在调用方法时内容类型未知，则 set_boundary() 方法将引发此错误。 当尝试创建一个看起来包含嵌入式标头的标头时 Header 可能会针对某些 base64 解码错误引发此错误（也就是说，应该是一个 没有前导空格并且看起来像标题的延续行）。

exception email.errors.BoundaryError

已弃用和不再使用的。

exception email.errors.MultipartConversionError

当使用 add_payload() 将有效负载添加到 Message 对象时，有效负载已经是一个标量，而消息的 Content-Type 主类型不是 multipart 或者缺少时触发该异常。 MultipartConversionError 多重继承自 MessageError 和内置的 TypeError。

Since Message.add_payload() is deprecated, this exception is rarely raised in practice. However the exception may also be raised if the attach() method is called on an instance of a class derived from MIMENonMultipart (e.g. MIMEImage).

Here is the list of the defects that the FeedParser can find while parsing messages. Note that the defects are added to the message where the problem was found, so for example, if a message nested inside a multipart/alternative had a malformed header, that nested message object would have a defect, but the containing messages would not.

All defect classes are subclassed from email.errors.MessageDefect.

  • NoBoundaryInMultipartDefect -- A message claimed to be a multipart, but had no boundary parameter.

  • StartBoundaryNotFoundDefect -- The start boundary claimed in the Content-Type header was never found.

  • CloseBoundaryNotFoundDefect -- A start boundary was found, but no corresponding close boundary was ever found.

    3.3 新版功能.

  • FirstHeaderLineIsContinuationDefect -- The message had a continuation line as its first header line.

  • MisplacedEnvelopeHeaderDefect - A "Unix From" header was found in the middle of a header block.

  • MissingHeaderBodySeparatorDefect - A line was found while parsing headers that had no leading white space but contained no ':'. Parsing continues assuming that the line represents the first line of the body.

    3.3 新版功能.

  • MalformedHeaderDefect -- A header was found that was missing a colon, or was otherwise malformed.

    3.3 版后已移除: This defect has not been used for several Python versions.

  • MultipartInvariantViolationDefect -- A message claimed to be a multipart, but no subparts were found. Note that when a message has this defect, its is_multipart() method may return False even though its content type claims to be multipart.

  • InvalidBase64PaddingDefect -- When decoding a block of base64 encoded bytes, the padding was not correct. Enough padding is added to perform the decode, but the resulting decoded bytes may be invalid.

  • InvalidBase64CharactersDefect -- When decoding a block of base64 encoded bytes, characters outside the base64 alphabet were encountered. The characters are ignored, but the resulting decoded bytes may be invalid.

  • InvalidBase64LengthDefect -- When decoding a block of base64 encoded bytes, the number of non-padding base64 characters was invalid (1 more than a multiple of 4). The encoded block was kept as-is.