numpy · ngoldbaum · Jun 17, 2024 · Jun 4, 2024 · Jun 5, 2024 · Jun 13, 2024
diff --git a/doc/release/upcoming_changes/26611.expired.rst b/doc/release/upcoming_changes/26611.expired.rst
@@ -0,0 +1,2 @@
+* ``set_string_function`` internal function was removed and ``PyArray_SetStringFunction``
+  was stubbed out.
diff --git a/doc/source/reference/c-api/array.rst b/doc/source/reference/c-api/array.rst
@@ -4077,21 +4077,6 @@ extension with the lowest :c:data:`NPY_FEATURE_VERSION` as possible.
     :c:data:`NPY_FEATURE_VERSION` changes whenever the API changes (e.g. a
     function is added). A changed value does not always require a recompile.
 
-Internal Flexibility
-~~~~~~~~~~~~~~~~~~~~
-
-.. c:function:: void PyArray_SetStringFunction(PyObject* op, int repr)
-
-    This function allows you to alter the tp_str and tp_repr methods
-    of the array object to any Python function. Thus you can alter
-    what happens for all arrays when str(arr) or repr(arr) is called
-    from Python. The function to be called is passed in as *op*. If
-    *repr* is non-zero, then this function will be called in response
-    to repr(arr), otherwise the function will be called in response to
-    str(arr). No check on whether or not *op* is callable is
-    performed. The callable passed in to *op* should expect an array
-    argument and should return a string to be printed.
-
 
 Memory management
 ~~~~~~~~~~~~~~~~~

diff --git a/doc/source/reference/c-api/types-and-structures.rst b/doc/source/reference/c-api/types-and-structures.rst
@@ -215,12 +215,11 @@ The :c:data:`PyArray_Type` can also be sub-typed.
 
 .. tip::
 
-    The ``tp_as_number`` methods use a generic approach to call whatever
-    function has been registered for handling the operation.  When the
-    ``_multiarray_umath module`` is imported, it sets the numeric operations
-    for all arrays to the corresponding ufuncs. This choice can be changed with
-    :c:func:`PyUFunc_ReplaceLoopBySignature` The ``tp_str`` and ``tp_repr``
-    methods can also be altered using :c:func:`PyArray_SetStringFunction`.
+    The :c:member:`tp_as_number <PyTypeObject.tp_as_number>` methods use
+    a generic approach to call whatever function has been registered for
+    handling the operation. When the ``_multiarray_umath`` module is imported,
+    it sets the numeric operations for all arrays to the corresponding ufuncs.
+    This choice can be changed with :c:func:`PyUFunc_ReplaceLoopBySignature`.
 
 PyGenericArrType_Type
 ---------------------

diff --git a/numpy/__init__.cython-30.pxd b/numpy/__init__.cython-30.pxd
@@ -608,7 +608,6 @@ cdef extern from "numpy/arrayobject.h":
     # more than is probably needed until it can be checked further.
     int PyArray_INCREF (ndarray) except *  # uses PyArray_Item_INCREF...
     int PyArray_XDECREF (ndarray) except *  # uses PyArray_Item_DECREF...
-    void PyArray_SetStringFunction (object, int)
     dtype PyArray_DescrFromType (int)
     object PyArray_TypeObjectFromType (int)
     char * PyArray_Zero (ndarray)

diff --git a/numpy/__init__.pxd b/numpy/__init__.pxd
@@ -523,7 +523,6 @@ cdef extern from "numpy/arrayobject.h":
     # more than is probably needed until it can be checked further.
     int PyArray_INCREF (ndarray) except *  # uses PyArray_Item_INCREF...
     int PyArray_XDECREF (ndarray) except *  # uses PyArray_Item_DECREF...
-    void PyArray_SetStringFunction (object, int)
     dtype PyArray_DescrFromType (int)
     object PyArray_TypeObjectFromType (int)
     char * PyArray_Zero (ndarray)

diff --git a/numpy/_core/_add_newdocs.py b/numpy/_core/_add_newdocs.py
@@ -1846,15 +1846,6 @@
 
     """)
 
-
-add_newdoc('numpy._core.multiarray', 'set_string_function',
-    """
-    set_string_function(f, repr=1)
-
-    Internal method to set a function to be used when pretty printing arrays.
-
-    """)
-
 add_newdoc('numpy._core.multiarray', 'promote_types',
     """
     promote_types(type1, type2)

diff --git a/numpy/_core/arrayprint.py b/numpy/_core/arrayprint.py
@@ -59,11 +59,14 @@
     'formatter': None,
     # Internally stored as an int to simplify comparisons; converted from/to
     # str/False on the way in/out.
-    'legacy': sys.maxsize}
+    'legacy': sys.maxsize,
+    'override_repr': None,
+}
 
 def _make_options_dict(precision=None, threshold=None, edgeitems=None,
                        linewidth=None, suppress=None, nanstr=None, infstr=None,
-                       sign=None, formatter=None, floatmode=None, legacy=None):
+                       sign=None, formatter=None, floatmode=None, legacy=None,
+                       override_repr=None):
     """
     Make a dictionary out of the non-None arguments, plus conversion of
     *legacy* and sanity checks.
@@ -119,7 +122,7 @@ def _make_options_dict(precision=None, threshold=None, edgeitems=None,
 def set_printoptions(precision=None, threshold=None, edgeitems=None,
                      linewidth=None, suppress=None, nanstr=None,
                      infstr=None, formatter=None, sign=None, floatmode=None,
-                     *, legacy=None):
+                     *, legacy=None, override_repr=None):
     """
     Set printing options.
 
@@ -224,6 +227,9 @@ def set_printoptions(precision=None, threshold=None, edgeitems=None,
 
         .. versionadded:: 1.14.0
         .. versionchanged:: 1.22.0
+    override_repr: callable, optional
+        If set a passed function will be used for generating arrays' repr.
+        Other options will be ignored.
 
     See Also
     --------
@@ -285,9 +291,10 @@ def set_printoptions(precision=None, threshold=None, edgeitems=None,
     """
     opt = _make_options_dict(precision, threshold, edgeitems, linewidth,
                              suppress, nanstr, infstr, sign, formatter,
-                             floatmode, legacy)
-    # formatter is always reset
+                             floatmode, legacy, override_repr)
+    # formatter and override_repr are always reset
     opt['formatter'] = formatter
+    opt['override_repr'] = override_repr
     _format_options.update(opt)
 
     # set the C variable for legacy mode
@@ -333,7 +340,7 @@ def get_printoptions():
     --------
 
     >>> np.get_printoptions()
-    {'edgeitems': 3, 'threshold': 1000, ..., 'legacy': False}
+    {'edgeitems': 3, 'threshold': 1000, ..., 'override_repr': None}
 
     >>> np.get_printoptions()['linewidth']
     75
@@ -1552,6 +1559,10 @@ def _array_repr_implementation(
         arr, max_line_width=None, precision=None, suppress_small=None,
         array2string=array2string):
     """Internal version of array_repr() that allows overriding array2string."""
+    override_repr = _format_options["override_repr"]
+    if override_repr is not None:
+        return override_repr(arr)
+
     if max_line_width is None:
         max_line_width = _format_options['linewidth']
 
@@ -1727,78 +1738,3 @@ def array_str(a, max_line_width=None, precision=None, suppress_small=None):
                                        array2string=_array2string_impl)
 _default_array_repr = functools.partial(_array_repr_implementation,
                                         array2string=_array2string_impl)
-
-
-def set_string_function(f, repr=True):
-    """
-    Set a Python function to be used when pretty printing arrays.
-
-    .. deprecated:: 2.0
-        Use `np.set_printoptions` instead with a formatter for custom
-        printing of NumPy objects.
-
-    Parameters
-    ----------
-    f : function or None
-        Function to be used to pretty print arrays. The function should expect
-        a single array argument and return a string of the representation of
-        the array. If None, the function is reset to the default NumPy function
-        to print arrays.
-    repr : bool, optional
-        If True (default), the function for pretty printing (``__repr__``)
-        is set, if False the function that returns the default string
-        representation (``__str__``) is set.
-
-    See Also
-    --------
-    set_printoptions, get_printoptions
-
-    Examples
-    --------
-    >>> from numpy._core.arrayprint import set_string_function
-    >>> def pprint(arr):
-    ...     return 'HA! - What are you going to do now?'
-    ...
-    >>> set_string_function(pprint)
-    >>> a = np.arange(10)
-    >>> a
-    HA! - What are you going to do now?
-    >>> _ = a
-    >>> # [0 1 2 3 4 5 6 7 8 9]
-
-    We can reset the function to the default:
-
-    >>> set_string_function(None)
-    >>> a
-    array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
-
-    `repr` affects either pretty printing or normal string representation.
-    Note that ``__repr__`` is still affected by setting ``__str__``
-    because the width of each array element in the returned string becomes
-    equal to the length of the result of ``__str__()``.
-
-    >>> x = np.arange(4)
-    >>> set_string_function(lambda x:'random', repr=False)
-    >>> x.__str__()
-    'random'
-    >>> x.__repr__()
-    'array([0, 1, 2, 3])'
-
-    """
-
-    # Deprecated in NumPy 2.0, 2023-07-11
-    warnings.warn(
-        "`set_string_function` is deprecated. Use `np.set_printoptions` "
-        "with a formatter for custom printing NumPy objects. "
-        "(deprecated in NumPy 2.0)",
-        DeprecationWarning,
-        stacklevel=2
-    )
-
-    if f is None:
-        if repr:
-            return multiarray.set_string_function(_default_array_repr, 1)
-        else:
-            return multiarray.set_string_function(_default_array_str, 0)
-    else:
-        return multiarray.set_string_function(f, repr)
diff --git a/numpy/_core/arrayprint.pyi b/numpy/_core/arrayprint.pyi
@@ -63,7 +63,8 @@ def set_printoptions(
     sign: Literal[None, "-", "+", " "] = ...,
     floatmode: None | _FloatMode = ...,
     *,
-    legacy: Literal[None, False, "1.13", "1.21"] = ...
+    legacy: Literal[None, False, "1.13", "1.21"] = ...,
+    override_repr: None | Callable[[NDArray[Any]], str] = ...,
 ) -> None: ...
 def get_printoptions() -> _FormatOptions: ...
 def array2string(

diff --git a/numpy/_core/code_generators/numpy_api.py b/numpy/_core/code_generators/numpy_api.py
@@ -116,6 +116,8 @@ def get_annotations():
     # Unused slot 41, was `PyArray_GetNumericOps`,
     'PyArray_INCREF':                       (42,),
     'PyArray_XDECREF':                      (43,),
+    # `PyArray_SetStringFunction` was stubbed out
+    # and should be removed in the future.
     'PyArray_SetStringFunction':            (44,),
     'PyArray_DescrFromType':                (45,),
     'PyArray_TypeObjectFromType':           (46,),

diff --git a/numpy/_core/src/multiarray/multiarraymodule.c b/numpy/_core/src/multiarray/multiarraymodule.c
@@ -3176,31 +3176,6 @@ array__reconstruct(PyObject *NPY_UNUSED(dummy), PyObject *args)
     return NULL;
 }
 
-static PyObject *
-array_set_string_function(PyObject *NPY_UNUSED(self), PyObject *args,
-        PyObject *kwds)
-{
-    PyObject *op = NULL;
-    int repr = 1;
-    static char *kwlist[] = {"f", "repr", NULL};
-
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|Oi:set_string_function", kwlist, &op, &repr)) {
-        return NULL;
-    }
-    /* reset the array_repr function to built-in */
-    if (op == Py_None) {
-        op = NULL;
-    }
-    if (op != NULL && !PyCallable_Check(op)) {
-        PyErr_SetString(PyExc_TypeError,
-                "Argument must be callable.");
-        return NULL;
-    }
-    PyArray_SetStringFunction(op, repr);
-    Py_RETURN_NONE;
-}
-
-
 static PyObject *
 array_set_datetimeparse_function(PyObject *NPY_UNUSED(self),
         PyObject *NPY_UNUSED(args), PyObject *NPY_UNUSED(kwds))
@@ -4417,9 +4392,6 @@ static struct PyMethodDef array_module_methods[] = {
     {"_reconstruct",
         (PyCFunction)array__reconstruct,
         METH_VARARGS, NULL},
-    {"set_string_function",
-        (PyCFunction)array_set_string_function,
-        METH_VARARGS|METH_KEYWORDS, NULL},
     {"set_datetimeparse_function",
         (PyCFunction)array_set_datetimeparse_function,
         METH_VARARGS|METH_KEYWORDS, NULL},

diff --git a/numpy/_core/src/multiarray/strfuncs.c b/numpy/_core/src/multiarray/strfuncs.c
@@ -9,10 +9,6 @@
 #include "npy_import.h"
 #include "strfuncs.h"
 
-static PyObject *PyArray_StrFunction = NULL;
-static PyObject *PyArray_ReprFunction = NULL;
-
-
 static void
 npy_PyErr_SetStringChained(PyObject *type, const char *message)
 {
@@ -30,34 +26,14 @@ npy_PyErr_SetStringChained(PyObject *type, const char *message)
 NPY_NO_EXPORT void
 PyArray_SetStringFunction(PyObject *op, int repr)
 {
-    if (repr) {
-        /* Dispose of previous callback */
-        Py_XDECREF(PyArray_ReprFunction);
-        /* Add a reference to new callback */
-        Py_XINCREF(op);
-        /* Remember new callback */
-        PyArray_ReprFunction = op;
-    }
-    else {
-        /* Dispose of previous callback */
-        Py_XDECREF(PyArray_StrFunction);
-        /* Add a reference to new callback */
-        Py_XINCREF(op);
-        /* Remember new callback */
-        PyArray_StrFunction = op;
-    }
+    PyErr_SetString(PyExc_ValueError, "PyArray_SetStringFunction was removed");
 }
 
 
 NPY_NO_EXPORT PyObject *
 array_repr(PyArrayObject *self)
 {
     static PyObject *repr = NULL;
-
-    if (PyArray_ReprFunction != NULL) {
-        return PyObject_CallFunctionObjArgs(PyArray_ReprFunction, self, NULL);
-    }
-
     /*
      * We need to do a delayed import here as initialization on module load
      * leads to circular import problems.
@@ -76,11 +52,6 @@ NPY_NO_EXPORT PyObject *
 array_str(PyArrayObject *self)
 {
     static PyObject *str = NULL;
-
-    if (PyArray_StrFunction != NULL) {
-        return PyObject_CallFunctionObjArgs(PyArray_StrFunction, self, NULL);
-    }
-
     /*
      * We need to do a delayed import here as initialization on module load leads
      * to circular import problems.

diff --git a/numpy/_core/tests/test_arrayprint.py b/numpy/_core/tests/test_arrayprint.py
@@ -667,6 +667,17 @@ def test_formatter_reset(self):
         np.set_printoptions(formatter={'float_kind':None})
         assert_equal(repr(x), "array([0., 1., 2.])")
 
+    def test_override_repr(self):
+        x = np.arange(3)
+        np.set_printoptions(override_repr=lambda x: "FOO")
+        assert_equal(repr(x), "FOO")
+        np.set_printoptions(override_repr=None)
+        assert_equal(repr(x), "array([0, 1, 2])")
+
+        with np.printoptions(override_repr=lambda x: "BAR"):
+            assert_equal(repr(x), "BAR")
+        assert_equal(repr(x), "array([0, 1, 2])")
+
     def test_0d_arrays(self):
         assert_equal(str(np.array('café', '<U4')), 'café')
 

diff --git a/numpy/_core/tests/test_multiarray.py b/numpy/_core/tests/test_multiarray.py
@@ -594,16 +594,16 @@ def assign(v):
     )
     def test_unicode_assignment(self):
         # gh-5049
-        from numpy._core.arrayprint import set_string_function
+        from numpy._core.arrayprint import set_printoptions
 
         @contextmanager
         def inject_str(s):
             """ replace ndarray.__str__ temporarily """
-            set_string_function(lambda x: s, repr=False)
+            set_printoptions(formatter={"all": lambda x: s})
             try:
                 yield
             finally:
-                set_string_function(None, repr=False)
+                set_printoptions()
 
         a1d = np.array(['test'])
         a0d = np.array('done')
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		* ``set_string_function`` internal function was removed and ``PyArray_SetStringFunction``
		was stubbed out.