Display \r and \t escape codes in string repr
diff --git a/py/objstr.c b/py/objstr.c
index 4c09871..d2d672b 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -63,7 +63,10 @@
             print(env, "%c", *s);
         } else if (*s == '\n') {
             print(env, "\\n");
-        // TODO add more escape codes here if we want to match CPython
+        } else if (*s == '\r') {
+            print(env, "\\r");
+        } else if (*s == '\t') {
+            print(env, "\\t");
         } else {
             print(env, "\\x%02x", *s);
         }