persistent_id(obj) Do nothing by default. This exists so a subclass can override it. If persistent_id() returns None, obj is pickled as usual. Any other value causes Pickler to emit the returned value as a persistent ID for obj. The meaning of this persistent ID should be defined by Unpickler.persistent_load(). Note that the value returned by persistent_id() cannot itself have a persistent ID. See Persistence of External Objects for details and examples of uses.

class email.headerregistry.ParameterizedMIMEHeader MOME headers all start with the prefix ‘Content-‘. Each specific header has a certain value, described under the class for that header. Some can also take a list of supplemental parameters, which have a common format. This class serves as a base for all the MIME headers that take parameters. params A dictionary mapping parameter names to parameter values.

@abc.abstractclassmethod A subclass of the built-in classmethod(), indicating an abstract classmethod. Otherwise it is similar to abstractmethod(). This special case is deprecated, as the classmethod() decorator is now correctly identified as abstract when applied to an abstract method: class C(metaclass=ABCMeta): @classmethod @abstractmethod def my_abstract_classmethod(cls, ...): ... New in version 3.2. Deprecated since version 3.3: It is now possible to use classmet

with_prefixlen

DatagramTransport.abort() Close the transport immediately, without waiting for pending operations to complete. Buffered data will be lost. No more data will be received. The protocol’s connection_lost() method will eventually be called with None as its argument.

class selectors.SelectorKey A SelectorKey is a namedtuple used to associate a file object to its underlying file decriptor, selected event mask and attached data. It is returned by several BaseSelector methods. fileobj File object registered. fd Underlying file descriptor. events Events that must be waited for on this file object. data Optional opaque data associated to this file object: for example, this could be used to store a per-client session ID.

ZipInfo.extra Expansion field data. The PKZIP Application Note contains some comments on the internal structure of the data contained in this string.

numerator Abstract.

st_mtime_ns Time of most recent content modification expressed in nanoseconds as an integer.

class smtplib.LMTP(host='', port=LMTP_PORT, local_hostname=None, source_address=None) The LMTP protocol, which is very similar to ESMTP, is heavily based on the standard SMTP client. It’s common to use Unix sockets for LMTP, so our connect() method must support that as well as a regular host:port server. The optional arguments local_hostname and source_address have the same meaning as they do in the SMTP class. To specify a Unix socket, you must use an absolute path for host, starting with a