Change 'null' to 'as_null'

python · mdickinson · Feb 10, 2024 · Feb 10, 2024 · Feb 10, 2024 · Feb 10, 2024
commit 79ce75e59e4251657ebfb1dce5bd2e94c595e1e3
diff --git a/Doc/library/json.rst b/Doc/library/json.rst
@@ -173,13 +173,13 @@ Basic Usage
    If *allow_nan* is false (default: ``True``), then it will be a
    :exc:`ValueError` to serialize out of range :class:`float` values (``nan``,
    ``inf``, ``-inf``) in strict compliance with the JSON specification. If
-   *allow_nan* is the string ``'null'``, NaNs and infinities will be converted
-   to a JSON ``null``, matching the behavior of JavaScript's
-   ``JSON.stringify``. If *allow_nan* is true but not equal to ``'null'`` then
-   NaNs and infinities are converted to non-quote-delimited strings ``NaN``,
-   ``Infinity`` and ``-Infinity`` in the JSON output. Note that this represents
-   an extension of the JSON specification, and is not compliant with standard
-   JSON.
+   *allow_nan* is the string ``'as_null'``, NaNs and infinities will be
+   converted to a JSON ``null``, matching the behavior of JavaScript's
+   ``JSON.stringify``. If *allow_nan* is true but not equal to ``'as_null'``
+   then NaNs and infinities are converted to non-quote-delimited strings
+   ``NaN``, ``Infinity`` and ``-Infinity`` in the JSON output. Note that this
+   represents an extension of the JSON specification, and is not compliant with
+   standard JSON.
 
    If *indent* is a non-negative integer or string, then JSON array elements and
    object members will be pretty-printed with that indent level.  An indent level
@@ -215,8 +215,8 @@ Basic Usage
       All optional parameters are now :ref:`keyword-only <keyword-only_parameter>`.
 
    .. versionchanged:: 3.14
-      Added support for ``allow_nan='null'``. Passing any string value
-      other than ``'null'`` for ``allow_nan`` now raises a
+      Added support for ``allow_nan='as_null'``. Passing any string value
+      other than ``'as_null'`` for ``allow_nan`` now raises a
       :warning:`DeprecationWarning`.
 
    .. note::
@@ -461,15 +461,15 @@ Encoders and Decoders
    prevent an infinite recursion (which would cause a :exc:`RecursionError`).
    Otherwise, no such check takes place.
 
-   If *allow_nan* is the string ``'null'``, then NaNs and infinities are
+   If *allow_nan* is the string ``'as_null'``, then NaNs and infinities are
    encoded as JSON ``null`` values. This matches the behavior of JavaScript's
-   ``JSON.stringify``. If *allow_nan* is true but not equal to ``'null'``, then
-   ``NaN``, ``Infinity``, and ``-Infinity`` will be encoded as corresponding
-   non-quote-delimited strings in the JSON output. This is the default
-   behavior. This behavior represents an extension of the JSON specification,
-   but is consistent with some JavaScript based encoders and decoders (as well
-   as Python's own decoder).  If *allow_nan* is false, it will be a
-   :exc:`ValueError` to encode such floats.
+   ``JSON.stringify``. If *allow_nan* is true but not equal to ``'as_null'``,
+   then ``NaN``, ``Infinity``, and ``-Infinity`` will be encoded as
+   corresponding non-quote-delimited strings in the JSON output. This is the
+   default behavior. This behavior represents an extension of the JSON
+   specification, but is consistent with some JavaScript based encoders and
+   decoders (as well as Python's own decoder).  If *allow_nan* is false, it
+   will be a :exc:`ValueError` to encode such floats.
 
    If *sort_keys* is true (default: ``False``), then the output of dictionaries
    will be sorted by key; this is useful for regression tests to ensure that
@@ -502,8 +502,8 @@ Encoders and Decoders
       All parameters are now :ref:`keyword-only <keyword-only_parameter>`.
 
    .. versionchanged:: 3.14
-      Added support for ``allow_nan='null'``. Passing any string value
-      other than ``'null'`` for ``allow_nan`` now raises a
+      Added support for ``allow_nan='as_null'``. Passing any string value
+      other than ``'as_null'`` for *allow_nan* now raises a
       :warning:`DeprecationWarning`.
 
    .. method:: default(o)

diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
@@ -761,14 +761,6 @@ itertools
   than the specified batch size.
   (Contributed by Raymond Hettinger in :gh:`113202`.)
 
-json
-----
-
-* Add support for ``allow_nan='null'`` when encoding to JSON. This converts
-  floating-point infinities and NaNs to a JSON ``null``, for compatibility
-  with ECMAScript's ``JSON.stringify``.
-  (Contributed by Mark Dickinson in :gh:`115246`.)
-
 marshal
 -------
 

diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
@@ -86,6 +86,14 @@ New Modules
 Improved Modules
 ================
 
+json
+----
+
+* Add support for ``allow_nan='as_null'`` when encoding to JSON. This converts
+  floating-point infinities and NaNs to a JSON ``null``, for compatibility
+  with ECMAScript's ``JSON.stringify``.
+  (Contributed by Mark Dickinson in :gh:`115246`.)
+
 
 Optimizations
 =============
@@ -181,4 +189,3 @@ Deprecated
 
 Removed
 -------
-
diff --git a/Include/internal/pycore_global_objects_fini_generated.h b/Include/internal/pycore_global_objects_fini_generated.h
diff --git a/Include/internal/pycore_global_strings.h b/Include/internal/pycore_global_strings.h
@@ -289,6 +289,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(arguments)
         STRUCT_FOR_ID(argv)
         STRUCT_FOR_ID(as_integer_ratio)
+        STRUCT_FOR_ID(as_null)
         STRUCT_FOR_ID(asend)
         STRUCT_FOR_ID(ast)
         STRUCT_FOR_ID(athrow)

diff --git a/Include/internal/pycore_runtime_init_generated.h b/Include/internal/pycore_runtime_init_generated.h
diff --git a/Include/internal/pycore_unicodeobject_generated.h b/Include/internal/pycore_unicodeobject_generated.h
diff --git a/Lib/json/encoder.py b/Lib/json/encoder.py
@@ -150,10 +150,10 @@ def __init__(self, *, skipkeys=False, ensure_ascii=True,
         self.ensure_ascii = ensure_ascii
         self.check_circular = check_circular
 
-        if isinstance(allow_nan, str) and allow_nan != "null":
+        if isinstance(allow_nan, str) and allow_nan != 'as_null':
             warnings.warn(
                 "in the future, allow_nan will no longer accept strings "
-                "other than 'null'. Use a boolean instead.",
+                "other than 'as_null'. Use a boolean instead.",
                 DeprecationWarning,
                 stacklevel=3,
             )
@@ -246,7 +246,7 @@ def floatstr(o, allow_nan=self.allow_nan,
             else:
                 return _repr(o)
 
-            if allow_nan == 'null':
+            if allow_nan == 'as_null':
                 return 'null'
 
             elif not allow_nan:

diff --git a/Lib/test/test_json/test_float.py b/Lib/test/test_json/test_float.py
@@ -35,29 +35,29 @@ def test_allow_nan(self):
             self.assertRaisesRegex(ValueError, msg, self.dumps, [val], allow_nan=False)
 
     def test_allow_nan_null(self):
-        # when allow_nan is "null", infinities and NaNs are converted to "null"
+        # when allow_nan is 'as_null', infinities and NaNs convert to 'null'
         for val in [float('inf'), float('-inf'), float('nan')]:
             with self.subTest(val=val):
-                out = self.dumps([val], allow_nan="null")
+                out = self.dumps([val], allow_nan='as_null')
                 res = self.loads(out)
                 self.assertEqual(res, [None])
 
         # and finite values are treated as normal
         for val in [1.25, -23, -0.0, 0.0]:
             with self.subTest(val=val):
-                out = self.dumps([val], allow_nan="null")
+                out = self.dumps([val], allow_nan='as_null')
                 res = self.loads(out)
                 self.assertEqual(res, [val])
 
         # testing a mixture
         vals = [-1.3, 1e100, -math.inf, 1234, -0.0, math.nan]
-        out = self.dumps(vals, allow_nan="null")
+        out = self.dumps(vals, allow_nan='as_null')
         res = self.loads(out)
         self.assertEqual(res, [-1.3, 1e100, None, 1234, -0.0, None])
 
     def test_allow_nan_string_deprecation(self):
         with self.assertWarns(DeprecationWarning):
-            self.dumps(2.3, allow_nan="true")
+            self.dumps(2.3, allow_nan='true')
 
     def test_allow_nan_non_boolean(self):
         # check that exception gets propagated as expected

diff --git a/Misc/NEWS.d/next/Library/2024-05-12-09-27-16.gh-issue-98306.dSlaEP.rst b/Misc/NEWS.d/next/Library/2024-05-12-09-27-16.gh-issue-98306.dSlaEP.rst
@@ -1,2 +1,2 @@
-Add support for ``allow_nan='null'`` when encoding an object to a JSON
+Add support for ``allow_nan='as_null'`` when encoding an object to a JSON
 string. This converts floating-point infinities and NaNs to a JSON ``null``.
diff --git a/Modules/_json.c b/Modules/_json.c
@@ -1229,7 +1229,8 @@ encoder_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     //   0 to disallow nans and infinities
     //   1 to convert nans and infinities into corresponding JSON strings
     //   2 to convert nans and infinities to a JSON null
-    if (PyUnicode_Check(allow_nan_obj) && _PyUnicode_Equal(allow_nan_obj, &_Py_ID(null))) {
+    if (PyUnicode_Check(allow_nan_obj) &&
+            _PyUnicode_Equal(allow_nan_obj, &_Py_ID(as_null))) {
         allow_nan = 2;
     } else {
         allow_nan = PyObject_IsTrue(allow_nan_obj);