下列异常类的定义在 email.errors 模块：
这异常基类引发通过 Parser 类。派生自 MessageError .
Raised under some error conditions when parsing the RFC 2822 headers of a message, this class is derived from MessageParseError . It can be raised from the Parser.parse or Parser.parsestr 方法。
Situations where it can be raised include finding an envelope header after the first RFC 2822 header of the message, finding a continuation line before the first RFC 2822 header is found, or finding a line in the headers which is neither a header or a continuation line.
Raised under some error conditions when parsing the RFC 2822 headers of a message, this class is derived from MessageParseError . It can be raised from the Parser.parse or Parser.parsestr 方法。
Situations where it can be raised include not being able to find the starting or terminating boundary in a multipart/* message when strict parsing is used.
被引发当将负载添加到 消息 对象使用 add_payload() , but the payload is already a scalar and the message’s Content-Type main type is not either multipart or missing. MultipartConversionError multiply inherits from MessageError 和内置 TypeError .
由于 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 (如 MIMEImage ).
Here’s 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.
所有子类化的缺陷类来自 email.errors.MessageDefect , but this class is not an exception!
New in version 2.4: All the defect classes were added.
