using f-strings instead of % operator

01-data-model/data-model.ipynb

@@ -482,7 +482,7 @@
     "        self.y = y\n",
     "\n",
     "    def __repr__(self):\n",
-    "        return 'Vector(%r, %r)' % (self.x, self.y)\n",
+    "        return f'Vector({self.x!r}, {self.y!r})'\n",
     "\n",
     "    def __abs__(self):\n",
     "        return math.hypot(self.x, self.y)\n",