bpo-46328: Add sys.exception() (GH-30514)

Python/clinic/sysmodule.c.h

@@ -76,6 +76,28 @@ exit:
     return return_value;
 }
 
+PyDoc_STRVAR(sys_exception__doc__,
+"exception($module, /)\n"
+"--\n"
+"\n"
+"Return the current exception.\n"
+"\n"
+"Return the most recent exception caught by an except clause\n"
+"in the current stack frame or in an older stack frame, or None\n"
+"if no such exception exists.");
+
+#define SYS_EXCEPTION_METHODDEF    \
+    {"exception", (PyCFunction)sys_exception, METH_NOARGS, sys_exception__doc__},
+
+static PyObject *
+sys_exception_impl(PyObject *module);
+
+static PyObject *
+sys_exception(PyObject *module, PyObject *Py_UNUSED(ignored))
+{
+    return sys_exception_impl(module);
+}
+
 PyDoc_STRVAR(sys_exc_info__doc__,
 "exc_info($module, /)\n"
 "--\n"
@@ -992,4 +1014,4 @@ sys_getandroidapilevel(PyObject *module, PyObject *Py_UNUSED(ignored))
 #ifndef SYS_GETANDROIDAPILEVEL_METHODDEF
     #define SYS_GETANDROIDAPILEVEL_METHODDEF
 #endif /* !defined(SYS_GETANDROIDAPILEVEL_METHODDEF) */
-/*[clinic end generated code: output=855fc93b2347710b input=a9049054013a1b77]*/
+/*[clinic end generated code: output=60756bc6f683e0c8 input=a9049054013a1b77]*/

Python/sysmodule.c

@@ -771,6 +771,28 @@ sys_excepthook_impl(PyObject *module, PyObject *exctype, PyObject *value,
 }
 
 
+/*[clinic input]
+sys.exception
+
+Return the current exception.
+
+Return the most recent exception caught by an except clause
+in the current stack frame or in an older stack frame, or None
+if no such exception exists.
+[clinic start generated code]*/
+
+static PyObject *
+sys_exception_impl(PyObject *module)
+/*[clinic end generated code: output=2381ee2f25953e40 input=c88fbb94b6287431]*/
+{
+    _PyErr_StackItem *err_info = _PyErr_GetTopmostException(_PyThreadState_GET());
+    if (err_info->exc_value != NULL) {
+        return Py_NewRef(err_info->exc_value);
+    }
+    Py_RETURN_NONE;
+}
+
+
 /*[clinic input]
 sys.exc_info
 
@@ -1963,6 +1985,7 @@ static PyMethodDef sys_methods[] = {
     SYS__CURRENT_FRAMES_METHODDEF
     SYS__CURRENT_EXCEPTIONS_METHODDEF
     SYS_DISPLAYHOOK_METHODDEF
+    SYS_EXCEPTION_METHODDEF
     SYS_EXC_INFO_METHODDEF
     SYS_EXCEPTHOOK_METHODDEF
     SYS_EXIT_METHODDEF
@@ -2457,7 +2480,8 @@ Functions:\n\
 \n\
 displayhook() -- print an object to the screen, and save it in builtins._\n\
 excepthook() -- print an exception and its traceback to sys.stderr\n\
-exc_info() -- return thread-safe information about the current exception\n\
+exception() -- return the current thread's active exception\n\
+exc_info() -- return information about the current thread's active exception\n\
 exit() -- exit the interpreter by raising SystemExit\n\
 getdlopenflags() -- returns flags to be used for dlopen() calls\n\
 getprofile() -- get the global profiling function\n\