Add warning for random.random

Lib/test/test_py2xwarn.py

@@ -38,6 +38,12 @@ def test_next(self):
             w.reset()
             self.assertNoWarning(iterator_marks.__next__(), w)
 
+    def test_random(self):
+        expected = "String repr of random.random() is longer in 3.x, change code accordingly"
+        import random
+        with check_py2x_warnings(("", Py2xWarning)) as w:
+            self.assertWarning(str(random.random()), w, expected)
+
     def test_truncate0(self):
         expected = "Calling truncate(0) on text stream without seek(0)" + \
         " may produce inconsistent results. Use seek(0) before truncate(0)"

Modules/_randommodule.c

@@ -72,6 +72,7 @@
 
 #include "Python.h"
 #include "pycore_moduleobject.h"  // _PyModule_GetState()
+#include "pg_float.h"
 #ifdef HAVE_PROCESS_H
 #  include <process.h>            // getpid()
 #endif
@@ -177,7 +178,14 @@ _random_Random_random_impl(RandomObject *self)
 /*[clinic end generated code: output=117ff99ee53d755c input=afb2a59cbbb00349]*/
 {
     uint32_t a=genrand_uint32(self)>>5, b=genrand_uint32(self)>>6;
-    return PyFloat_FromDouble((a*67108864.0+b)*(1.0/9007199254740992.0));
+    double x = (a * 67108864.0 + b) * (1.0 / 9007199254740992.0);
+    if (Py_Py2xWarningFlag){
+        return PgFloat_FromDouble(x,1);   
+    }
+    else{
+        return PyFloat_FromDouble(x);
+    }
+
 }
 
 /* initializes mt[N] with a seed */

Modules/pg_float.c

@@ -0,0 +1,68 @@
+#define PY_SSIZE_T_CLEAN
+#include "Python.h"
+#include "pg_float.h"
+
+typedef struct {
+    PyFloatObject base;
+    unsigned char from_random; // 1 = from random, 0 = not from random
+} PgFloatObject;
+
+static PyTypeObject PgFloat_Type;
+static int g_ready = 0;
+
+extern int Py_Py2xWarningFlag;
+
+static PyObject *
+PgFloat_str(PyObject *v)
+{
+    PgFloatObject *self = (PgFloatObject *)v;
+
+    if (Py_Py2xWarningFlag && self->from_random && PyErr_WarnEx(
+        PyExc_Py2xWarning,
+        "String repr of random.random() is longer in 3.x, change code accordingly",
+        2) < 0){
+            return NULL;
+    }
+
+    return PyFloat_Type.tp_str(v);
+}
+
+static PyTypeObject PgFloat_Type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    .tp_name      = "pg_float.PgFloat",
+    .tp_basicsize = sizeof(PgFloatObject),
+    .tp_flags     = Py_TPFLAGS_DEFAULT,
+    .tp_base      = &PyFloat_Type,
+    .tp_str       = PgFloat_str,
+};
+
+int
+PgFloat_Initialize(void)
+{
+    if (g_ready) return 0;
+    if (PyType_Ready(&PgFloat_Type) < 0)
+        return -1;
+    g_ready = 1;
+    return 0;
+}
+
+PyObject *
+PgFloat_FromDouble(double x, int from_random)
+{
+    if (!g_ready && PgFloat_Initialize() < 0)
+        return NULL;
+
+    PgFloatObject *op = (PgFloatObject *)PyObject_New(PgFloatObject, &PgFloat_Type);
+    if (!op) return NULL;
+    op->base.ob_fval = x;
+    op->from_random = from_random ? 1 : 0;
+    return (PyObject *)op;
+}
+
+PyTypeObject *
+PgFloat_TypeObj(void)
+{
+    if (!g_ready && PgFloat_Initialize() < 0)
+        return NULL;
+    return &PgFloat_Type;
+}

Modules/pg_float.h

@@ -0,0 +1,12 @@
+#ifndef PG_FLOAT_H
+#define PG_FLOAT_H
+
+#include "Python.h"
+
+PyAPI_FUNC(int) PgFloat_Initialize(void);
+
+PyAPI_FUNC(PyObject*) PgFloat_FromDouble(double x, int from_random);
+
+PyAPI_FUNC(PyTypeObject*) PgFloat_TypeObj(void);
+
+#endif /* PG_FLOAT_H */

setup.py

@@ -940,7 +940,7 @@ def detect_simple_extensions(self):
         self.addext(Extension('_datetime', ['_datetimemodule.c']))
         self.addext(Extension('_zoneinfo', ['_zoneinfo.c']))
         # random number generator implemented in C
-        self.addext(Extension("_random", ["_randommodule.c"]))
+        self.addext(Extension("_random", ["_randommodule.c", "pg_float.c"]))
         self.addext(Extension("_bisect", ["_bisectmodule.c"]))
         self.addext(Extension("_heapq", ["_heapqmodule.c"]))
         # C-optimized pickle replacement