bpo-37999: No longer use __int__ in implicit integer conversions. (GH-15636)

Only __index__ should be used to make integer conversions lossless.

Author: serhiy-storchaka

Doc/whatsnew/3.10.rst

@@ -75,6 +75,12 @@ New Features
 Other Language Changes
 ======================
 
+* Builtin and extension functions that take integer arguments no longer accept
+  :class:`~decimal.Decimal`\ s, :class:`~fractions.Fraction`\ s and other
+  objects that can be converted to integers only with a loss (e.g. that have
+  the :meth:`~object.__int__` method but do not have the
+  :meth:`~object.__index__` method).
+  (Contributed by Serhiy Storchaka in :issue:`37999`.)
 
 
 New Modules

Include/longobject.h

@@ -173,23 +173,6 @@ PyAPI_FUNC(int) _PyLong_AsByteArray(PyLongObject* v,
     unsigned char* bytes, size_t n,
     int little_endian, int is_signed);
 
-/* _PyLong_FromNbInt: Convert the given object to a PyLongObject
-   using the nb_int slot, if available.  Raise TypeError if either the
-   nb_int slot is not available or the result of the call to nb_int
-   returns something not of type int.
-*/
-PyAPI_FUNC(PyObject *) _PyLong_FromNbInt(PyObject *);
-
-/* Convert the given object to a PyLongObject using the nb_index or
-   nb_int slots, if available (the latter is deprecated).
-   Raise TypeError if either nb_index and nb_int slots are not
-   available or the result of the call to nb_index or nb_int
-   returns something not of type int.
-   Should be replaced with PyNumber_Index after the end of the
-   deprecation period.
-*/
-PyAPI_FUNC(PyObject *) _PyLong_FromNbIndexOrNbInt(PyObject *);
-
 /* _PyLong_Format: Convert the long to a string object with given base,
    appending a base prefix of 0[box] if base is 2, 8 or 16. */
 PyAPI_FUNC(PyObject *) _PyLong_Format(PyObject *obj, int base);

Lib/ctypes/test/test_numbers.py

@@ -134,8 +134,7 @@ def __index__(self):
         for t in signed_types + unsigned_types:
             self.assertRaises(TypeError, t, 3.14)
             self.assertRaises(TypeError, t, f)
-            with self.assertWarns(DeprecationWarning):
-                self.assertEqual(t(d).value, 2)
+            self.assertRaises(TypeError, t, d)
             self.assertEqual(t(i).value, 2)
 
     def test_sizes(self):

Lib/datetime.py

@@ -11,6 +11,7 @@
 import time as _time
 import math as _math
 import sys
+from operator import index as _index
 
 def _cmp(x, y):
     return 0 if x == y else 1 if x > y else -1
@@ -380,42 +381,10 @@ def _check_utc_offset(name, offset):
                          "-timedelta(hours=24) and timedelta(hours=24)" %
                          (name, offset))
 
-def _check_int_field(value):
-    if isinstance(value, int):
-        return value
-    if isinstance(value, float):
-        raise TypeError('integer argument expected, got float')
-    try:
-        value = value.__index__()
-    except AttributeError:
-        pass
-    else:
-        if not isinstance(value, int):
-            raise TypeError('__index__ returned non-int (type %s)' %
-                            type(value).__name__)
-        return value
-    orig = value
-    try:
-        value = value.__int__()
-    except AttributeError:
-        pass
-    else:
-        if not isinstance(value, int):
-            raise TypeError('__int__ returned non-int (type %s)' %
-                            type(value).__name__)
-        import warnings
-        warnings.warn("an integer is required (got type %s)"  %
-                      type(orig).__name__,
-                      DeprecationWarning,
-                      stacklevel=2)
-        return value
-    raise TypeError('an integer is required (got type %s)' %
-                    type(value).__name__)
-
 def _check_date_fields(year, month, day):
-    year = _check_int_field(year)
-    month = _check_int_field(month)
-    day = _check_int_field(day)
+    year = _index(year)
+    month = _index(month)
+    day = _index(day)
     if not MINYEAR <= year <= MAXYEAR:
         raise ValueError('year must be in %d..%d' % (MINYEAR, MAXYEAR), year)
     if not 1 <= month <= 12:
@@ -426,10 +395,10 @@ def _check_date_fields(year, month, day):
     return year, month, day
 
 def _check_time_fields(hour, minute, second, microsecond, fold):
-    hour = _check_int_field(hour)
-    minute = _check_int_field(minute)
-    second = _check_int_field(second)
-    microsecond = _check_int_field(microsecond)
+    hour = _index(hour)
+    minute = _index(minute)
+    second = _index(second)
+    microsecond = _index(microsecond)
     if not 0 <= hour <= 23:
         raise ValueError('hour must be in 0..23', hour)
     if not 0 <= minute <= 59:
@@ -2539,10 +2508,10 @@ def _name_from_offset(delta):
     # Clean up unused names
     del (_DAYNAMES, _DAYS_BEFORE_MONTH, _DAYS_IN_MONTH, _DI100Y, _DI400Y,
          _DI4Y, _EPOCH, _MAXORDINAL, _MONTHNAMES, _build_struct_time,
-         _check_date_fields, _check_int_field, _check_time_fields,
+         _check_date_fields, _check_time_fields,
          _check_tzinfo_arg, _check_tzname, _check_utc_offset, _cmp, _cmperror,
          _date_class, _days_before_month, _days_before_year, _days_in_month,
-         _format_time, _format_offset, _is_leap, _isoweek1monday, _math,
+         _format_time, _format_offset, _index, _is_leap, _isoweek1monday, _math,
          _ord2ymd, _time, _time_class, _tzinfo_class, _wrap_strftime, _ymd2ord,
          _divide_and_round, _parse_isoformat_date, _parse_isoformat_time,
          _parse_hh_mm_ss_ff, _IsoCalendarDate)

Lib/test/clinic.test

@@ -418,11 +418,6 @@ test_bool_converter(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
     if (nargs < 3) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[2])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     c = _PyLong_AsInt(args[2]);
     if (c == -1 && PyErr_Occurred()) {
         goto exit;
@@ -436,7 +431,7 @@ exit:
 
 static PyObject *
 test_bool_converter_impl(PyObject *module, int a, int b, int c)
-/*[clinic end generated code: output=25f20963894256a1 input=939854fa9f248c60]*/
+/*[clinic end generated code: output=b5ec6409d942e0f9 input=939854fa9f248c60]*/
 
 
 /*[clinic input]
@@ -729,11 +724,6 @@ test_unsigned_char_converter(PyObject *module, PyObject *const *args, Py_ssize_t
     if (nargs < 1) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[0])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     {
         long ival = PyLong_AsLong(args[0]);
         if (ival == -1 && PyErr_Occurred()) {
@@ -756,11 +746,6 @@ test_unsigned_char_converter(PyObject *module, PyObject *const *args, Py_ssize_t
     if (nargs < 2) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[1])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     {
         long ival = PyLong_AsLong(args[1]);
         if (ival == -1 && PyErr_Occurred()) {
@@ -783,14 +768,9 @@ test_unsigned_char_converter(PyObject *module, PyObject *const *args, Py_ssize_t
     if (nargs < 3) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[2])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     {
-        long ival = PyLong_AsUnsignedLongMask(args[2]);
-        if (ival == -1 && PyErr_Occurred()) {
+        unsigned long ival = PyLong_AsUnsignedLongMask(args[2]);
+        if (ival == (unsigned long)-1 && PyErr_Occurred()) {
             goto exit;
         }
         else {
@@ -807,7 +787,7 @@ exit:
 static PyObject *
 test_unsigned_char_converter_impl(PyObject *module, unsigned char a,
                                   unsigned char b, unsigned char c)
-/*[clinic end generated code: output=ebf905c5c9414762 input=021414060993e289]*/
+/*[clinic end generated code: output=c0a6ab3144481466 input=021414060993e289]*/
 
 
 /*[clinic input]
@@ -841,11 +821,6 @@ test_short_converter(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
     if (nargs < 1) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[0])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     {
         long ival = PyLong_AsLong(args[0]);
         if (ival == -1 && PyErr_Occurred()) {
@@ -874,7 +849,7 @@ exit:
 
 static PyObject *
 test_short_converter_impl(PyObject *module, short a)
-/*[clinic end generated code: output=86fe1a1496a7ff20 input=6a8a7a509a498ff4]*/
+/*[clinic end generated code: output=3ccda4bd08b6e4b4 input=6a8a7a509a498ff4]*/
 
 
 /*[clinic input]
@@ -925,11 +900,6 @@ test_unsigned_short_converter(PyObject *module, PyObject *const *args, Py_ssize_
     if (nargs < 3) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[2])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     c = (unsigned short)PyLong_AsUnsignedLongMask(args[2]);
     if (c == (unsigned short)-1 && PyErr_Occurred()) {
         goto exit;
@@ -944,7 +914,7 @@ exit:
 static PyObject *
 test_unsigned_short_converter_impl(PyObject *module, unsigned short a,
                                    unsigned short b, unsigned short c)
-/*[clinic end generated code: output=3779fe104319e3ae input=cdfd8eff3d9176b4]*/
+/*[clinic end generated code: output=576b5ce48424f351 input=cdfd8eff3d9176b4]*/
 
 
 /*[clinic input]
@@ -984,23 +954,13 @@ test_int_converter(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
     if (nargs < 1) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[0])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     a = _PyLong_AsInt(args[0]);
     if (a == -1 && PyErr_Occurred()) {
         goto exit;
     }
     if (nargs < 2) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[1])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     b = _PyLong_AsInt(args[1]);
     if (b == -1 && PyErr_Occurred()) {
         goto exit;
@@ -1023,11 +983,6 @@ test_int_converter(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
     if (nargs < 4) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[3])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     d = _PyLong_AsInt(args[3]);
     if (d == -1 && PyErr_Occurred()) {
         goto exit;
@@ -1041,7 +996,7 @@ exit:
 
 static PyObject *
 test_int_converter_impl(PyObject *module, int a, int b, int c, myenum d)
-/*[clinic end generated code: output=10a2e48a34af5d7a input=d20541fc1ca0553e]*/
+/*[clinic end generated code: output=8a1a7b02ebe9eeac input=d20541fc1ca0553e]*/
 
 
 /*[clinic input]
@@ -1092,11 +1047,6 @@ test_unsigned_int_converter(PyObject *module, PyObject *const *args, Py_ssize_t
     if (nargs < 3) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[2])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     c = (unsigned int)PyLong_AsUnsignedLongMask(args[2]);
     if (c == (unsigned int)-1 && PyErr_Occurred()) {
         goto exit;
@@ -1111,7 +1061,7 @@ exit:
 static PyObject *
 test_unsigned_int_converter_impl(PyObject *module, unsigned int a,
                                  unsigned int b, unsigned int c)
-/*[clinic end generated code: output=189176ce67c7d2e7 input=5533534828b62fc0]*/
+/*[clinic end generated code: output=4f53904bfa1a0250 input=5533534828b62fc0]*/
 
 
 /*[clinic input]
@@ -1145,11 +1095,6 @@ test_long_converter(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
     if (nargs < 1) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[0])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     a = PyLong_AsLong(args[0]);
     if (a == -1 && PyErr_Occurred()) {
         goto exit;
@@ -1163,7 +1108,7 @@ exit:
 
 static PyObject *
 test_long_converter_impl(PyObject *module, long a)
-/*[clinic end generated code: output=44cd8823f59d116b input=d2179e3c9cdcde89]*/
+/*[clinic end generated code: output=e5e7883fddcf4218 input=d2179e3c9cdcde89]*/
 
 
 /*[clinic input]
@@ -1263,11 +1208,6 @@ test_long_long_converter(PyObject *module, PyObject *const *args, Py_ssize_t nar
     if (nargs < 1) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[0])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     a = PyLong_AsLongLong(args[0]);
     if (a == -1 && PyErr_Occurred()) {
         goto exit;
@@ -1281,7 +1221,7 @@ exit:
 
 static PyObject *
 test_long_long_converter_impl(PyObject *module, long long a)
-/*[clinic end generated code: output=7143b585d7e433e8 input=d5fc81577ff4dd02]*/
+/*[clinic end generated code: output=0488ac9e8c1d77bb input=d5fc81577ff4dd02]*/
 
 
 /*[clinic input]
@@ -1390,11 +1330,6 @@ test_Py_ssize_t_converter(PyObject *module, PyObject *const *args, Py_ssize_t na
     if (nargs < 1) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[0])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     {
         Py_ssize_t ival = -1;
         PyObject *iobj = PyNumber_Index(args[0]);
@@ -1410,11 +1345,6 @@ test_Py_ssize_t_converter(PyObject *module, PyObject *const *args, Py_ssize_t na
     if (nargs < 2) {
         goto skip_optional;
     }
-    if (PyFloat_Check(args[1])) {
-        PyErr_SetString(PyExc_TypeError,
-                        "integer argument expected, got float" );
-        goto exit;
-    }
     {
         Py_ssize_t ival = -1;
         PyObject *iobj = PyNumber_Index(args[1]);
@@ -1443,7 +1373,7 @@ exit:
 static PyObject *
 test_Py_ssize_t_converter_impl(PyObject *module, Py_ssize_t a, Py_ssize_t b,
                                Py_ssize_t c)
-/*[clinic end generated code: output=a46d2aaf40c10398 input=3855f184bb3f299d]*/
+/*[clinic end generated code: output=ea781bb7169b3436 input=3855f184bb3f299d]*/
 
 
 /*[clinic input]