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[3.13] Docs: mark up json.load() using parameter list (GH-128488) (#128596)
(cherry picked from commit a21e31e) Co-authored-by: Erlend E. Aasland <[email protected]>
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Doc/library/json.rst

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@@ -258,64 +258,89 @@ Basic Usage
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the original one. That is, ``loads(dumps(x)) != x`` if x has non-string
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keys.
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.. function:: load(fp, *, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw)
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.. function:: load(fp, *, cls=None, object_hook=None, parse_float=None, \
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parse_int=None, parse_constant=None, \
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object_pairs_hook=None, **kw)
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Deserialize *fp* (a ``.read()``-supporting :term:`text file` or
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:term:`binary file` containing a JSON document) to a Python object using
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this :ref:`conversion table <json-to-py-table>`.
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Deserialize *fp* to a Python object
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using the :ref:`JSON-to-Python conversion table <json-to-py-table>`.
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*object_hook* is an optional function that will be called with the result of
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any object literal decoded (a :class:`dict`). The return value of
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*object_hook* will be used instead of the :class:`dict`. This feature can
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be used to implement custom decoders (e.g. `JSON-RPC
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<https://www.jsonrpc.org>`_ class hinting).
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:param fp:
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A ``.read()``-supporting :term:`text file` or :term:`binary file`
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containing the JSON document to be deserialized.
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:type fp: :term:`file-like object`
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*object_pairs_hook* is an optional function that will be called with the
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result of any object literal decoded with an ordered list of pairs. The
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return value of *object_pairs_hook* will be used instead of the
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:class:`dict`. This feature can be used to implement custom decoders. If
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*object_hook* is also defined, the *object_pairs_hook* takes priority.
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:param cls:
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If set, a custom JSON decoder.
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Additional keyword arguments to :func:`!load`
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will be passed to the constructor of *cls*.
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If ``None`` (the default), :class:`!JSONDecoder` is used.
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:type cls: a :class:`JSONDecoder` subclass
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:param object_hook:
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If set, a function that is called with the result of
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any object literal decoded (a :class:`dict`).
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The return value of this function will be used
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instead of the :class:`dict`.
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This feature can be used to implement custom decoders,
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for example `JSON-RPC <https://www.jsonrpc.org>`_ class hinting.
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Default ``None``.
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:type object_hook: :term:`callable` | None
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:param object_pairs_hook:
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If set, a function that is called with the result of
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any object literal decoded with an ordered list of pairs.
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The return value of this function will be used
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instead of the :class:`dict`.
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This feature can be used to implement custom decoders.
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If *object_hook* is also set, *object_pairs_hook* takes priority.
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Default ``None``.
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:type object_pairs_hook: :term:`callable` | None
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:param parse_float:
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If set, a function that is called with
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the string of every JSON float to be decoded.
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If ``None`` (the default), it is equivalent to ``float(num_str)``.
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This can be used to parse JSON floats into custom datatypes,
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for example :class:`decimal.Decimal`.
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:type parse_float: :term:`callable` | None
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:param parse_int:
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If set, a function that is called with
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the string of every JSON int to be decoded.
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If ``None`` (the default), it is equivalent to ``int(num_str)``.
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This can be used to parse JSON integers into custom datatypes,
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for example :class:`float`.
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:type parse_int: :term:`callable` | None
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:param parse_constant:
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If set, a function that is called with one of the following strings:
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``'-Infinity'``, ``'Infinity'``, or ``'NaN'``.
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This can be used to raise an exception
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if invalid JSON numbers are encountered.
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Default ``None``.
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:type parse_constant: :term:`callable` | None
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:raises JSONDecodeError:
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When the data being deserialized is not a valid JSON document.
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.. versionchanged:: 3.1
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Added support for *object_pairs_hook*.
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*parse_float* is an optional function that will be called with the string of
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every JSON float to be decoded. By default, this is equivalent to
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``float(num_str)``. This can be used to use another datatype or parser for
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JSON floats (e.g. :class:`decimal.Decimal`).
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* Added the optional *object_pairs_hook* parameter.
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* *parse_constant* doesn't get called on 'null', 'true', 'false' anymore.
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*parse_int* is an optional function that will be called with the string of
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every JSON int to be decoded. By default, this is equivalent to
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``int(num_str)``. This can be used to use another datatype or parser for
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JSON integers (e.g. :class:`float`).
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.. versionchanged:: 3.6
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* All optional parameters are now :ref:`keyword-only <keyword-only_parameter>`.
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* *fp* can now be a :term:`binary file`.
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The input encoding should be UTF-8, UTF-16 or UTF-32.
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.. versionchanged:: 3.11
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The default *parse_int* of :func:`int` now limits the maximum length of
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the integer string via the interpreter's :ref:`integer string
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conversion length limitation <int_max_str_digits>` to help avoid denial
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of service attacks.
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*parse_constant* is an optional function that will be called with one of the
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following strings: ``'-Infinity'``, ``'Infinity'``, ``'NaN'``. This can be
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used to raise an exception if invalid JSON numbers are encountered.
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.. versionchanged:: 3.1
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*parse_constant* doesn't get called on 'null', 'true', 'false' anymore.
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To use a custom :class:`JSONDecoder` subclass, specify it with the ``cls``
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kwarg; otherwise :class:`JSONDecoder` is used. Additional keyword arguments
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will be passed to the constructor of the class.
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If the data being deserialized is not a valid JSON document, a
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:exc:`JSONDecodeError` will be raised.
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.. versionchanged:: 3.6
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All optional parameters are now :ref:`keyword-only <keyword-only_parameter>`.
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.. versionchanged:: 3.6
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*fp* can now be a :term:`binary file`. The input encoding should be
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UTF-8, UTF-16 or UTF-32.
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.. function:: loads(s, *, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw)
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Deserialize *s* (a :class:`str`, :class:`bytes` or :class:`bytearray`

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