.. _noneobject:
-The None Object
----------------
+The ``None`` Object
+-------------------
.. index:: object: None
.. c:macro:: Py_RETURN_NONE
Properly handle returning :c:data:`Py_None` from within a C function (that is,
- increment the reference count of None and return it.)
+ increment the reference count of ``None`` and return it.)
decode characters.
Decoding mappings must map single string characters to single Unicode
-characters, integers (which are then interpreted as Unicode ordinals) or None
+characters, integers (which are then interpreted as Unicode ordinals) or ``None``
(meaning "undefined mapping" and causing an error).
Encoding mappings must map single Unicode characters to single string
-characters, integers (which are then interpreted as Latin-1 ordinals) or None
+characters, integers (which are then interpreted as Latin-1 ordinals) or ``None``
(meaning "undefined mapping" and causing an error).
The mapping objects provided must only support the __getitem__ mapping
*NULL* when an exception was raised by the codec.
The *mapping* table must map Unicode ordinal integers to Unicode ordinal
- integers or None (causing deletion of the character).
+ integers or ``None`` (causing deletion of the character).
Mapping tables need only provide the :meth:`__getitem__` interface; dictionaries
and sequences work well. Unmapped character ordinals (ones which cause a
resulting Unicode object.
The mapping table must map Unicode ordinal integers to Unicode ordinal integers
- or None (causing deletion of the character).
+ or ``None`` (causing deletion of the character).
Mapping tables need only provide the :meth:`__getitem__` interface; dictionaries
and sequences work well. Unmapped character ordinals (ones which cause a
While they could have been implemented that way, the actual C implementation of
:c:type:`PyMethod_Type` in :source:`Objects/classobject.c` is a single object
with two different representations depending on whether the :attr:`im_self`
-field is set or is *NULL* (the C equivalent of *None*).
+field is set or is *NULL* (the C equivalent of ``None``).
Likewise, the effects of calling a method object depend on the :attr:`im_self`
field. If set (meaning bound), the original function (stored in the
The handler's level is set to ``WARNING``, so all events at this and
greater severities will be output.
-To obtain the pre-3.2 behaviour, ``logging.lastResort`` can be set to *None*.
+To obtain the pre-3.2 behaviour, ``logging.lastResort`` can be set to ``None``.
.. _library-config:
[1, 2, 3, 4, 5]
You can also use the :meth:`list.sort` method. It modifies the list
-in-place (and returns *None* to avoid confusion). Usually it's less convenient
+in-place (and returns ``None`` to avoid confusion). Usually it's less convenient
than :func:`sorted` - but if you don't need the original list, it's slightly
more efficient.
positional arguments
* description - description for the sub-parser group in help output, by
- default None
+ default ``None``
* prog - usage information that will be displayed with sub-command help,
by default the name of the program and any positional arguments before the
encountered at the command line
* dest_ - name of the attribute under which sub-command name will be
- stored; by default None and no value is stored
+ stored; by default ``None`` and no value is stored
- * help_ - help for sub-parser group in help output, by default None
+ * help_ - help for sub-parser group in help output, by default ``None``
* metavar_ - string presenting available sub-commands in help; by default it
- is None and presents sub-commands in form {cmd1, cmd2, ..}
+ is ``None`` and presents sub-commands in form {cmd1, cmd2, ..}
Some example usage::
(for example by calling :meth:`write_eof`, if the other end also uses
asyncio).
- This method may return a false value (including None), in which case
+ This method may return a false value (including ``None``), in which case
the transport will close itself. Conversely, if this method returns a
true value, closing the transport is up to the protocol. Since the
- default implementation returns None, it implicitly closes the connection.
+ default implementation returns ``None``, it implicitly closes the connection.
.. note::
Some transports such as SSL don't support half-closed connections,
Enter a polling loop that terminates after count passes or all open
channels have been closed. All arguments are optional. The *count*
- parameter defaults to None, resulting in the loop terminating only when all
+ parameter defaults to ``None``, resulting in the loop terminating only when all
channels have been closed. The *timeout* argument sets the timeout
parameter for the appropriate :func:`~select.select` or :func:`~select.poll`
call, measured in seconds; the default is 30 seconds. The *use_poll*
.. method:: set_continue()
Stop only at breakpoints or when finished. If there are no breakpoints,
- set the system trace function to None.
+ set the system trace function to ``None``.
.. method:: set_quit()
position of the underlying data representation.
- If *maxlen* is not specified or is *None*, deques may grow to an
+ If *maxlen* is not specified or is ``None``, deques may grow to an
arbitrary length. Otherwise, the deque is bounded to the specified maximum
length. Once a bounded length deque is full, when new items are added, a
corresponding number of items are discarded from the opposite end. Bounded
.. attribute:: maxlen
- Maximum size of a deque or *None* if unbounded.
+ Maximum size of a deque or ``None`` if unbounded.
.. versionadded:: 3.1
notably :func:`get_instructions`, as iterating over a :class:`Bytecode`
instance yields the bytecode operations as :class:`Instruction` instances.
- If *first_line* is not None, it indicates the line number that should be
+ If *first_line* is not ``None``, it indicates the line number that should be
reported for the first source line in the disassembled code. Otherwise, the
source line information (if any) is taken directly from the disassembled code
object.
- If *current_offset* is not None, it refers to an instruction offset in the
+ If *current_offset* is not ``None``, it refers to an instruction offset in the
disassembled code. Setting this means :meth:`.dis` will display a "current
instruction" marker against the specified opcode.
The iterator generates a series of :class:`Instruction` named tuples giving
the details of each operation in the supplied code.
- If *first_line* is not None, it indicates the line number that should be
+ If *first_line* is not ``None``, it indicates the line number that should be
reported for the first source line in the disassembled code. Otherwise, the
source line information (if any) is taken directly from the disassembled code
object.
.. data:: arg
- numeric argument to operation (if any), otherwise None
+ numeric argument to operation (if any), otherwise ``None``
.. data:: argval
.. data:: starts_line
- line started by this opcode (if any), otherwise None
+ line started by this opcode (if any), otherwise ``None``
.. data:: is_jump_target
.. attribute:: docstring
- The string that the test was extracted from, or 'None' if the string is
+ The string that the test was extracted from, or ``None`` if the string is
unavailable, or if the test was not extracted from a string.
not specified, then ``obj.__name__`` is used.
The optional parameter *module* is the module that contains the given object.
- If the module is not specified or is None, then the test finder will attempt
+ If the module is not specified or is ``None``, then the test finder will attempt
to automatically determine the correct module. The object's module is used:
* As a default namespace, if *globs* is not specified.
Bootstraps ``pip`` into the current or designated environment.
*root* specifies an alternative root directory to install relative to.
- If *root* is None, then installation uses the default install location
+ If *root* is ``None``, then installation uses the default install location
for the current environment.
*upgrade* indicates whether or not to upgrade an existing installation
Since a dictionary is used to cache results, the positional and keyword
arguments to the function must be hashable.
- If *maxsize* is set to None, the LRU feature is disabled and the cache can
+ If *maxsize* is set to ``None``, the LRU feature is disabled and the cache can
grow without bound. The LRU feature performs best when *maxsize* is a
power-of-two.
.. method:: date_time_string(timestamp=None)
- Returns the date and time given by *timestamp* (which must be None or in
+ Returns the date and time given by *timestamp* (which must be ``None`` or in
the format returned by :func:`time.time`), formatted for a message
header. If *timestamp* is omitted, it uses the current date and time.
Parse an IMAP4 ``INTERNALDATE`` string and return corresponding local
time. The return value is a :class:`time.struct_time` tuple or
- None if the string has wrong format.
+ ``None`` if the string has wrong format.
.. function:: Int2AP(num)
(``__loader__``)
The loader to use for loading. For namespace packages this should be
- set to None.
+ set to ``None``.
.. attribute:: origin
Name of the place from which the module is loaded, e.g. "builtin" for
built-in modules and the filename for modules loaded from source.
- Normally "origin" should be set, but it may be None (the default)
+ Normally "origin" should be set, but it may be ``None`` (the default)
which indicates it is unspecified.
.. attribute:: submodule_search_locations
(``__path__``)
- List of strings for where to find submodules, if a package (None
+ List of strings for where to find submodules, if a package (``None``
otherwise).
.. attribute:: loader_state
Container of extra module-specific data for use during loading (or
- None).
+ ``None``).
.. attribute:: cached
(``__cached__``)
- String for where the compiled module should be stored (or None).
+ String for where the compiled module should be stored (or ``None``).
.. attribute:: parent
(``__package__``)
(Read-only) Fully-qualified name of the package to which the module
- belongs as a submodule (or None).
+ belongs as a submodule (or ``None``).
.. attribute:: has_location
(to raise :exc:`TypeError`).
If *skipkeys* is false (the default), then it is a :exc:`TypeError` to
- attempt encoding of keys that are not str, int, float or None. If
- *skipkeys* is true, such items are simply skipped.
+ attempt encoding of keys that are not :class:`str`, :class:`int`,
+ :class:`float` or ``None``. If *skipkeys* is true, such items are simply
+ skipped.
If *ensure_ascii* is true (the default), the output is guaranteed to
have all incoming non-ASCII characters escaped. If *ensure_ascii* is
.. function:: lazycache(filename, module_globals)
Capture enough detail about a non-file-based module to permit getting its
- lines later via :func:`getline` even if *module_globals* is None in the later
+ lines later via :func:`getline` even if *module_globals* is ``None`` in the later
call. This avoids doing I/O until a line is actually needed, without having
to carry the module globals around indefinitely.
across the socket, such that the ``verify`` callable can perform
signature verification and/or decryption. The ``verify`` callable is called
with a single argument - the bytes received across the socket - and should
- return the bytes to be processed, or None to indicate that the bytes should
+ return the bytes to be processed, or ``None`` to indicate that the bytes should
be discarded. The returned bytes could be the same as the passed in bytes
(e.g. when only verification is done), or they could be completely different
(perhaps if decryption were performed).
Returns a new instance of the :class:`FileHandler` class. The specified file is
opened and used as the stream for logging. If *mode* is not specified,
- :const:`'a'` is used. If *encoding* is not *None*, it is used to open the file
+ :const:`'a'` is used. If *encoding* is not ``None``, it is used to open the file
with that encoding. If *delay* is true, then file opening is deferred until the
first call to :meth:`emit`. By default, the file grows indefinitely.
Returns a new instance of the :class:`WatchedFileHandler` class. The specified
file is opened and used as the stream for logging. If *mode* is not specified,
- :const:`'a'` is used. If *encoding* is not *None*, it is used to open the file
+ :const:`'a'` is used. If *encoding* is not ``None``, it is used to open the file
with that encoding. If *delay* is true, then file opening is deferred until the
first call to :meth:`emit`. By default, the file grows indefinitely.
Returns a new instance of the :class:`RotatingFileHandler` class. The specified
file is opened and used as the stream for logging. If *mode* is not specified,
- ``'a'`` is used. If *encoding* is not *None*, it is used to open the file
+ ``'a'`` is used. If *encoding* is not ``None``, it is used to open the file
with that encoding. If *delay* is true, then file opening is deferred until the
first call to :meth:`emit`. By default, the file grows indefinitely.
Finds the caller's source filename and line number. Returns the filename, line
number, function name and stack information as a 4-element tuple. The stack
- information is returned as *None* unless *stack_info* is *True*.
+ information is returned as ``None`` unless *stack_info* is *True*.
.. method:: Logger.handle(record)
:param args: Variable data to merge into the *msg* argument to obtain the
event description.
:param exc_info: An exception tuple with the current exception information,
- or *None* if no exception information is available.
+ or ``None`` if no exception information is available.
:param func: The name of the function or method from which the logging call
was invoked.
:param sinfo: A text string representing stack information from the base of
| | | (as returned by :func:`time.time`). |
+----------------+-------------------------+-----------------------------------------------+
| exc_info | You shouldn't need to | Exception tuple (Ã la ``sys.exc_info``) or, |
-| | format this yourself. | if no exception has occurred, *None*. |
+| | format this yourself. | if no exception has occurred, ``None``. |
+----------------+-------------------------+-----------------------------------------------+
| filename | ``%(filename)s`` | Filename portion of ``pathname``. |
+----------------+-------------------------+-----------------------------------------------+
:lno: The line number in the file where the logging call was made.
:msg: The logging message.
:args: The arguments for the logging message.
- :exc_info: An exception tuple, or None.
+ :exc_info: An exception tuple, or ``None``.
:func: The name of the function or method which invoked the logging
call.
:sinfo: A stack traceback such as is provided by
.. method:: read([n])
Return a :class:`bytes` containing up to *n* bytes starting from the
- current file position. If the argument is omitted, *None* or negative,
+ current file position. If the argument is omitted, ``None`` or negative,
return all bytes from the current file position to the end of the
mapping. The file position is updated to point after the bytes that were
returned.
.. versionchanged:: 3.3
- Argument can be omitted or *None*.
+ Argument can be omitted or ``None``.
.. method:: read_byte()
Return a context object which has the same attributes as the
:mod:`multiprocessing` module.
- If *method* is *None* then the default context is returned.
+ If *method* is ``None`` then the default context is returned.
Otherwise *method* should be ``'fork'``, ``'spawn'``,
``'forkserver'``. :exc:`ValueError` is raised if the specified
start method is not available.
If the start method has not been fixed and *allow_none* is false,
then the start method is fixed to the default and the name is
returned. If the start method has not been fixed and *allow_none*
- is true then *None* is returned.
+ is true then ``None`` is returned.
The return value can be ``'fork'``, ``'spawn'``, ``'forkserver'``
- or *None*. ``'fork'`` is the default on Unix, while ``'spawn'`` is
+ or ``None``. ``'fork'`` is the default on Unix, while ``'spawn'`` is
the default on Windows.
.. versionadded:: 3.4
*maxtasksperchild* is the number of tasks a worker process can complete
before it will exit and be replaced with a fresh worker process, to enable
- unused resources to be freed. The default *maxtasksperchild* is None, which
+ unused resources to be freed. The default *maxtasksperchild* is ``None``, which
means worker processes will live as long as the pool.
*context* can be used to specify the context used for starting
``None`` then digest authentication is used.
If *authkey* is a byte string then it will be used as the
- authentication key; otherwise it must be *None*.
+ authentication key; otherwise it must be ``None``.
If *authkey* is ``None`` and *authenticate* is ``True`` then
``current_process().authkey`` is used as the authentication key. If
.. method:: NNTP.login(user=None, password=None, usenetrc=True)
Send ``AUTHINFO`` commands with the user name and password. If *user*
- and *password* are None and *usenetrc* is true, credentials from
+ and *password* are ``None`` and *usenetrc* is true, credentials from
``~/.netrc`` will be used if possible.
Unless intentionally delayed, login is normally performed during the
values.ensure_value(attr, value)
- If the ``attr`` attribute of ``values`` doesn't exist or is None, then
+ If the ``attr`` attribute of ``values`` doesn't exist or is ``None``, then
ensure_value() first sets it to ``value``, and then returns 'value. This is
very handy for actions like ``"extend"``, ``"append"``, and ``"count"``, all
of which accumulate data in a variable and expect that variable to be of a
certain type (a list for the first two, an integer for the latter). Using
:meth:`ensure_value` means that scripts using your action don't have to worry
about setting a default value for the option destinations in question; they
- can just leave the default as None and :meth:`ensure_value` will take care of
+ can just leave the default as ``None`` and :meth:`ensure_value` will take care of
getting it right when it's needed.
executable, similar to a shell, when launching a process.
*env*, when specified, should be an environment variable dictionary
to lookup the PATH in.
- By default, when *env* is None, :data:`environ` is used.
+ By default, when *env* is ``None``, :data:`environ` is used.
.. versionadded:: 3.2
.. function:: cpu_count()
- Return the number of CPUs in the system. Returns None if undetermined.
+ Return the number of CPUs in the system. Returns ``None`` if undetermined.
.. versionadded:: 3.4
.. method:: Queue.put(item, block=True, timeout=None)
Put *item* into the queue. If optional args *block* is true and *timeout* is
- None (the default), block if necessary until a free slot is available. If
+ ``None`` (the default), block if necessary until a free slot is available. If
*timeout* is a positive number, it blocks at most *timeout* seconds and raises
the :exc:`Full` exception if no free slot was available within that time.
Otherwise (*block* is false), put an item on the queue if a free slot is
.. method:: Queue.get(block=True, timeout=None)
Remove and return an item from the queue. If optional args *block* is true and
- *timeout* is None (the default), block if necessary until an item is available.
+ *timeout* is ``None`` (the default), block if necessary until an item is available.
If *timeout* is a positive number, it blocks at most *timeout* seconds and
raises the :exc:`Empty` exception if no item was available within that time.
Otherwise (*block* is false), return an item if one is immediately available,
Low level interface to kevent
- - changelist must be an iterable of kevent object or None
+ - changelist must be an iterable of kevent object or ``None``
- max_events must be 0 or a positive integer
- timeout in seconds (floats possible)
:rfc:`4954` "initial response" bytes which will be encoded and sent with
the ``AUTH`` command as below. If the ``authobject()`` does not support an
initial response (e.g. because it requires a challenge), it should return
- None when called with ``challenge=None``. If *initial_response_ok* is
- false, then ``authobject()`` will not be called first with None.
+ ``None`` when called with ``challenge=None``. If *initial_response_ok* is
+ false, then ``authobject()`` will not be called first with ``None``.
- If the initial response check returns None, or if *initial_response_ok* is
+ If the initial response check returns ``None``, or if *initial_response_ok* is
false, ``authobject()`` will be called to process the server's challenge
response; the *challenge* argument it is passed will be a ``bytes``. It
should return ``bytes`` *data* that will be base64 encoded and sent to the
If *keyfile* and *certfile* are provided, these are passed to the :mod:`socket`
module's :func:`ssl` function.
- Optional *context* parameter is a :class:`ssl.SSLContext` object; This is an alternative to
- using a keyfile and a certfile and if specified both *keyfile* and *certfile* should be None.
+ Optional *context* parameter is a :class:`ssl.SSLContext` object; This is
+ an alternative to using a keyfile and a certfile and if specified both
+ *keyfile* and *certfile* should be ``None``.
If there has been no previous ``EHLO`` or ``HELO`` command this session,
this method tries ESMTP ``EHLO`` first.
called as the SQL function.
The function can return any of the types supported by SQLite: bytes, str, int,
- float and None.
+ float and ``None``.
Example:
final result of the aggregate.
The ``finalize`` method can return any of the types supported by SQLite:
- bytes, str, int, float and None.
+ bytes, str, int, float and ``None``.
Example:
.. literalinclude:: ../includes/sqlite3/collation_reverse.py
- To remove a collation, call ``create_collation`` with None as callable::
+ To remove a collation, call ``create_collation`` with ``None`` as callable::
con.create_collation("reverse", None)
(or none at all) via the *isolation_level* parameter to the :func:`connect`
call, or via the :attr:`isolation_level` property of connections.
-If you want **autocommit mode**, then set :attr:`isolation_level` to None.
+If you want **autocommit mode**, then set :attr:`isolation_level` to ``None``.
Otherwise leave it at its default, which will result in a plain "BEGIN"
statement, or set it to one of SQLite's supported isolation levels: "DEFERRED",
:meth:`SSLContext.set_default_verify_paths`. The return value is a
:term:`named tuple` ``DefaultVerifyPaths``:
- * :attr:`cafile` - resolved path to cafile or None if the file doesn't exist,
- * :attr:`capath` - resolved path to capath or None if the directory doesn't exist,
+ * :attr:`cafile` - resolved path to cafile or ``None`` if the file doesn't exist,
+ * :attr:`capath` - resolved path to capath or ``None`` if the directory doesn't exist,
* :attr:`openssl_cafile_env` - OpenSSL's environment key that points to a cafile,
* :attr:`openssl_cafile` - hard coded path to a cafile,
* :attr:`openssl_capath_env` - OpenSSL's environment key that points to a capath,
If there is only one argument, it must be a dictionary mapping Unicode
ordinals (integers) or characters (strings of length 1) to Unicode ordinals,
- strings (of arbitrary lengths) or None. Character keys will then be
+ strings (of arbitrary lengths) or ``None``. Character keys will then be
converted to ordinals.
If there are two arguments, they must be strings of equal length, and in the
resulting dictionary, each character in x will be mapped to the character at
the same position in y. If there is a third argument, it must be a string,
- whose characters will be mapped to None in the result.
+ whose characters will be mapped to ``None`` in the result.
.. method:: str.partition(sep)
memory as an N-dimensional array.
.. versionchanged:: 3.3
- An empty tuple instead of None when ndim = 0.
+ An empty tuple instead of ``None`` when ndim = 0.
.. attribute:: strides
access each element for each dimension of the array.
.. versionchanged:: 3.3
- An empty tuple instead of None when ndim = 0.
+ An empty tuple instead of ``None`` when ndim = 0.
.. attribute:: suboffsets
In addition to the above presentation types, integers can be formatted
with the floating point presentation types listed below (except
-``'n'`` and None). When doing so, :func:`float` is used to convert the
+``'n'`` and ``None``). When doing so, :func:`float` is used to convert the
integer to a floating point number before formatting.
The available presentation types for floating point and decimal values are:
.. attribute:: stdout
Captured stdout from the child process. A bytes sequence, or a string if
- :func:`run` was called with ``universal_newlines=True``. None if stdout
+ :func:`run` was called with ``universal_newlines=True``. ``None`` if stdout
was not captured.
If you ran the process with ``stderr=subprocess.STDOUT``, stdout and
stderr will be combined in this attribute, and :attr:`stderr` will be
- None.
+ ``None``.
.. attribute:: stderr
Captured stderr from the child process. A bytes sequence, or a string if
- :func:`run` was called with ``universal_newlines=True``. None if stderr
+ :func:`run` was called with ``universal_newlines=True``. ``None`` if stderr
was not captured.
.. method:: check_returncode()
.. note::
Under some conditions ``stdin``, ``stdout`` and ``stderr`` as well as the
original values ``__stdin__``, ``__stdout__`` and ``__stderr__`` can be
- None. It is usually the case for Windows GUI apps that aren't connected
+ ``None``. It is usually the case for Windows GUI apps that aren't connected
to a console and Python apps started with :program:`pythonw`.
A context manager that creates a temporary directory at *path* and
yields the directory.
- If *path* is None, the temporary directory is created using
+ If *path* is ``None``, the temporary directory is created using
:func:`tempfile.mkdtemp`. If *quiet* is ``False``, the context manager
raises an exception on error. Otherwise, if *path* is specified and
cannot be created, only a warning is issued.
The context manager creates a temporary directory in the current
directory with name *name* before temporarily changing the current
- working directory. If *name* is None, the temporary directory is
+ working directory. If *name* is ``None``, the temporary directory is
created using :func:`tempfile.mkdtemp`.
If *quiet* is ``False`` and it is not possible to create or change
without an argument would block, return false immediately; otherwise,
do the same thing as when called without arguments, and return true.
- When invoked with a *timeout* other than None, it will block for at
+ When invoked with a *timeout* other than ``None``, it will block for at
most *timeout* seconds. If acquire does not complete successfully in
that interval, return false. Return true otherwise.
Create a timer that will run *function* with arguments *args* and keyword
arguments *kwargs*, after *interval* seconds have passed.
- If *args* is None (the default) then an empty list will be used.
- If *kwargs* is None (the default) then an empty dict will be used.
+ If *args* is ``None`` (the default) then an empty list will be used.
+ If *kwargs* is ``None`` (the default) then an empty dict will be used.
.. versionchanged:: 3.3
changed from a factory function to a class.
Layouts
^^^^^^^
-A layout can be just None, if it takes no options, or a dict of
+A layout can be just ``None``, if it takes no options, or a dict of
options specifying how to arrange the element. The layout mechanism
uses a simplified version of the pack geometry manager: given an
initial cavity, each element is allocated a parcel. Valid
:param n: an integer (or ``None``)
- Delete all or first/last *n* of turtle's stamps. If *n* is None, delete
+ Delete all or first/last *n* of turtle's stamps. If *n* is ``None``, delete
all stamps, if *n* > 0 delete first *n* stamps, else if *n* < 0 delete
last *n* stamps.
Pop up a dialog window for input of a string. Parameter title is
the title of the dialog window, propmt is a text mostly describing
what information to input.
- Return the string input. If the dialog is canceled, return None. ::
+ Return the string input. If the dialog is canceled, return ``None``. ::
>>> screen.textinput("NIM", "Name of first player:")
The number input must be in the range minval .. maxval if these are
given. If not, a hint is issued and the dialog remains open for
correction.
- Return the number input. If the dialog is canceled, return None. ::
+ Return the number input. If the dialog is canceled, return ``None``. ::
>>> screen.numinput("Poker", "Your stakes:", 1000, minval=10, maxval=10000)
:param height: if an integer, the height in pixels, if a float, a fraction of
the screen; default is 75% of screen
:param startx: if positive, starting position in pixels from the left
- edge of the screen, if negative from the right edge, if None,
+ edge of the screen, if negative from the right edge, if ``None``,
center window horizontally
:param starty: if positive, starting position in pixels from the top
- edge of the screen, if negative from the bottom edge, if None,
+ edge of the screen, if negative from the bottom edge, if ``None``,
center window vertically
.. doctest::
This is often the same as ``obj.__annotations__``, but it handles
forward references encoded as string literals, and if necessary
- adds ``Optional[t]`` if a default value equal to None is set.
+ adds ``Optional[t]`` if a default value equal to ``None`` is set.
.. decorator:: overload
.. versionadded:: 3.5
- * *wraps*: Item for the mock object to wrap. If *wraps* is not None then
+ * *wraps*: Item for the mock object to wrap. If *wraps* is not ``None`` then
calling the Mock will pass the call through to the wrapped object
(returning the real result). Attribute access on the mock will return a
Mock object that wraps the corresponding attribute of the wrapped
.. method:: assertIsNone(expr, msg=None)
assertIsNotNone(expr, msg=None)
- Test that *expr* is (or is not) None.
+ Test that *expr* is (or is not) ``None``.
.. versionadded:: 3.1
methods that delegate to it), :meth:`assertDictEqual` and
:meth:`assertMultiLineEqual`.
- Setting ``maxDiff`` to None means that there is no maximum length of
+ Setting ``maxDiff`` to ``None`` means that there is no maximum length of
diffs.
.. versionadded:: 3.2
.. attribute:: Request.data
- The entity body for the request, or None if not specified.
+ The entity body for the request, or ``None`` if not specified.
.. versionchanged:: 3.4
Changing value of :attr:`Request.data` now deletes "Content-Length"
Get the byte stream for this input source.
The getEncoding method will return the character encoding for this byte stream,
- or None if unknown.
+ or ``None`` if unknown.
.. method:: InputSource.setCharacterStream(charfile)
the archive will be written to that file.
* If it is an open file object, the archive will be written to that
file object, which must be open for writing in bytes mode.
- * If the target is omitted (or None), the source must be a directory
+ * If the target is omitted (or ``None``), the source must be a directory
and the target will be a file with the same name as the source, with
a ``.pyz`` extension added.
dictionary containing the class's namespace; :attr:`~class.__bases__` is a
tuple (possibly empty or a singleton) containing the base classes, in the
order of their occurrence in the base class list; :attr:`__doc__` is the
- class's documentation string, or None if undefined.
+ class's documentation string, or ``None`` if undefined.
Class instances
.. index::
be a :term:`keyword argument`. The user-supplied filter function accepts a
:class:`~tarfile.TarInfo` object and returns an updated
:class:`~tarfile.TarInfo` object, or if it wants the file to be excluded, the
-function can return *None*::
+function can return ``None``::
>>> import tarfile, glob
syntax. The :func:`ast.literal_eval` function serves as a secure alternative to
the builtin :func:`eval` function which is easily abused. Python 3.2 adds
:class:`bytes` and :class:`set` literals to the list of supported types:
-strings, bytes, numbers, tuples, lists, dicts, sets, booleans, and None.
+strings, bytes, numbers, tuples, lists, dicts, sets, booleans, and ``None``.
::
* The maximum number of dimensions is officially limited to 64.
* The representation of empty shape, strides and suboffsets is now
- an empty tuple instead of None.
+ an empty tuple instead of ``None``.
* Accessing a memoryview element with format 'B' (unsigned bytes)
now returns an integer (in accordance with the struct module syntax).
* :ref:`Safe object finalization <whatsnew-pep-442>` (:pep:`442`).
* Leveraging :pep:`442`, in most cases :ref:`module globals are no longer set
- to None during finalization <whatsnew-pep-442>` (:issue:`18214`).
+ to ``None`` during finalization <whatsnew-pep-442>` (:issue:`18214`).
* :ref:`Configurable memory allocators <whatsnew-pep-445>` (:pep:`445`).
* :ref:`Argument Clinic <whatsnew-pep-436>` (:pep:`436`).
projects / python / commitdiff