email.contentmanager: Managing MIME Content¶
Source code: Lib/email/contentmanager.py
3.6 新版功能: 1
Base class for content managers. Provides the standard registry mechanisms to register converters between MIME content and other representations, as well as the
get_content(msg, *args, **kw)¶
Look up a handler function based on the
mimetypeof msg (see next paragraph), call it, passing through all arguments, and return the result of the call. The expectation is that the handler will extract the payload from msg and return an object that encodes information about the extracted data.
To find the handler, look for the following keys in the registry, stopping with the first one found:
the string representing the full MIME type (
the string representing the
the empty string
If none of these keys produce a handler, raise a
KeyErrorfor the full MIME type.
set_content(msg, obj, *args, **kw)¶
multipart, raise a
TypeError; otherwise look up a handler function based on the type of obj (see next paragraph), call
clear_content()on the msg, and call the handler function, passing through all arguments. The expectation is that the handler will transform and store obj into msg, possibly making other changes to msg as well, such as adding various MIME headers to encode information needed to interpret the stored data.
To find the handler, obtain the type of obj (
typ = type(obj)), and look for the following keys in the registry, stopping with the first one found:
the type itself (
the type's fully qualified name (
typ.__module__ + '.' + typ.__qualname__).
the type's qualname (
the type's name (
If none of the above match, repeat all of the checks above for each of the types in the MRO (
typ.__mro__). Finally, if no other key yields a handler, check for a handler for the key
None. If there is no handler for
None, raise a
KeyErrorfor the fully qualified name of the type.
Also add a MIME-Version header if one is not present (see also
Record the function handler as the handler for key. For the possible values of key, see
Record handler as the function to call when an object of a type matching typekey is passed to
set_content(). For the possible values of typekey, see
Content Manager Instances¶
Currently the email package provides only one concrete content manager,
raw_data_manager, although more may be added in the future.
raw_data_manager is the
content_manager provided by
EmailPolicy and its derivatives.
This content manager provides only a minimum interface beyond that provided by
Messageitself: it deals only with text, raw byte strings, and
Messageobjects. Nevertheless, it provides significant advantages compared to the base API:
get_contenton a text part will return a unicode string without the application needing to manually decode it,
set_contentprovides a rich set of options for controlling the headers added to a part and controlling the content transfer encoding, and it enables the use of the various
add_methods, thereby simplifying the creation of multipart messages.
Return the payload of the part as either a string (for
message/rfc822parts), or a
bytesobject (for all other non-multipart types). Raise a
KeyErrorif called on a
multipart. If the part is a
textpart and errors is specified, use it as the error handler when decoding the payload to unicode. The default error handler is
set_content(msg, <'str'>, subtype="plain", charset='utf-8' cte=None, disposition=None, filename=None, cid=None, params=None, headers=None)¶
set_content(msg, <'bytes'>, maintype, subtype, cte="base64", disposition=None, filename=None, cid=None, params=None, headers=None)
set_content(msg, <'EmailMessage'>, cte=None, disposition=None, filename=None, cid=None, params=None, headers=None)
Add headers and payload to msg:
Add a Content-Type header with a
str, set the MIME
text, and set the subtype to subtype if it is specified, or
plainif it is not.
bytes, use the specified maintype and subtype, or raise a
TypeErrorif they are not specified.
EmailMessageobjects, set the maintype to
message, and set the subtype to subtype if it is specified or
rfc822if it is not. If subtype is
partial, raise an error (
bytesobjects must be used to construct
If charset is provided (which is valid only for
str), encode the string to bytes using the specified character set. The default is
utf-8. If the specified charset is a known alias for a standard MIME charset name, use the standard charset instead.
If cte is set, encode the payload using the specified content transfer encoding, and set the Content-Transfer-Encoding header to that value. Possible values for cte are
binary. If the input cannot be encoded in the specified encoding (for example, specifying a cte of
7bitfor an input that contains non-ASCII values), raise a
strobjects, if cte is not set use heuristics to determine the most compact encoding.
EmailMessage, per RFC 2046, raise an error if a cte of
base64is requested for subtype
rfc822, and for any cte other than
8bitif cte is not specified. For all other values of subtype, use
A cte of
binarydoes not actually work correctly yet. The
EmailMessageobject as modified by
set_contentis correct, but
BytesGeneratordoes not serialize it correctly.
If disposition is set, use it as the value of the Content-Disposition header. If not specified, and filename is specified, add the header with the value
attachment. If disposition is not specified and filename is also not specified, do not add the header. The only valid values for disposition are
If filename is specified, use it as the value of the
filenameparameter of the Content-Disposition header.
If cid is specified, add a Content-ID header with cid as its value.
If params is specified, iterate its
itemsmethod and use the resulting
(key, value)pairs to set additional parameters on the Content-Type header.
If headers is specified and is a list of strings of the form
headername: headervalueor a list of
headerobjects (distinguished from strings by having a
nameattribute), add the headers to msg.
Originally added in 3.4 as a provisional module