bpo-32468: Better frame repr() (#5067)

bpo-32468: Better frame repr()
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 6ab3a22..1ac3d75 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -547,6 +547,15 @@
 PyDoc_STRVAR(sizeof__doc__,
 "F.__sizeof__() -> size of F in memory, in bytes");
 
+static PyObject *
+frame_repr(PyFrameObject *f)
+{
+    int lineno = PyFrame_GetLineNumber(f);
+    return PyUnicode_FromFormat(
+        "<frame at %p, file %R, line %d, code %S>",
+        f, f->f_code->co_filename, lineno, f->f_code->co_name);
+}
+
 static PyMethodDef frame_methods[] = {
     {"clear",           (PyCFunction)frame_clear,       METH_NOARGS,
      clear__doc__},
@@ -565,7 +574,7 @@
     0,                                          /* tp_getattr */
     0,                                          /* tp_setattr */
     0,                                          /* tp_reserved */
-    0,                                          /* tp_repr */
+    (reprfunc)frame_repr,                       /* tp_repr */
     0,                                          /* tp_as_number */
     0,                                          /* tp_as_sequence */
     0,                                          /* tp_as_mapping */