debug

test.ipynb

@@ -553,6 +553,29 @@
     "G.has_edge(1, 2, 1)"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1\n"
+     ]
+    }
+   ],
+   "source": [
+    "s = set()\n",
+    "s.add(1)\n",
+    "s.add(2)\n",
+    "s.add(1)\n",
+    "len(s)\n",
+    "if s:\n",
+    "    print(1)"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,