diff --git a/02-array-seq/array-seq.ipynb b/02-array-seq/array-seq.ipynb
index afdbf6b..085d4df 100644
--- a/02-array-seq/array-seq.ipynb
+++ b/02-array-seq/array-seq.ipynb
@@ -44,7 +44,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[36, 162, 163, 165, 8364, 164]"
+      "text/plain": [
+       "[36, 162, 163, 165, 8364, 164]"
+      ]
      },
      "execution_count": 1,
      "metadata": {},
@@ -75,7 +77,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[36, 162, 163, 165, 8364, 164]"
+      "text/plain": [
+       "[36, 162, 163, 165, 8364, 164]"
+      ]
      },
      "execution_count": 2,
      "metadata": {},
@@ -104,7 +108,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "'ABC'"
+      "text/plain": [
+       "'ABC'"
+      ]
      },
      "execution_count": 3,
      "metadata": {},
@@ -124,7 +130,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[65, 66, 67]"
+      "text/plain": [
+       "[65, 66, 67]"
+      ]
      },
      "execution_count": 4,
      "metadata": {},
@@ -138,10 +146,18 @@
   {
    "cell_type": "code",
    "execution_count": 5,
+   "metadata": {
+    "collapsed": false,
+    "pycharm": {
+     "name": "#%%\n"
+    }
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "67"
+      "text/plain": [
+       "67"
+      ]
      },
      "execution_count": 5,
      "metadata": {},
@@ -151,13 +167,7 @@
    "source": [
     "codes = [last := ord(c) for c in x]\n",
     "last"
-   ],
-   "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
-   }
+   ]
   },
   {
    "cell_type": "markdown",
@@ -173,7 +183,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[162, 163, 165, 8364, 164]"
+      "text/plain": [
+       "[162, 163, 165, 8364, 164]"
+      ]
      },
      "execution_count": 6,
      "metadata": {},
@@ -193,7 +205,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[162, 163, 165, 8364, 164]"
+      "text/plain": [
+       "[162, 163, 165, 8364, 164]"
+      ]
      },
      "execution_count": 7,
      "metadata": {},
@@ -219,7 +233,14 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[('black', 'S'),\n ('black', 'M'),\n ('black', 'L'),\n ('white', 'S'),\n ('white', 'M'),\n ('white', 'L')]"
+      "text/plain": [
+       "[('black', 'S'),\n",
+       " ('black', 'M'),\n",
+       " ('black', 'L'),\n",
+       " ('white', 'S'),\n",
+       " ('white', 'M'),\n",
+       " ('white', 'L')]"
+      ]
      },
      "execution_count": 8,
      "metadata": {},
@@ -264,7 +285,14 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[('black', 'S'),\n ('black', 'M'),\n ('black', 'L'),\n ('white', 'S'),\n ('white', 'M'),\n ('white', 'L')]"
+      "text/plain": [
+       "[('black', 'S'),\n",
+       " ('black', 'M'),\n",
+       " ('black', 'L'),\n",
+       " ('white', 'S'),\n",
+       " ('white', 'M'),\n",
+       " ('white', 'L')]"
+      ]
      },
      "execution_count": 10,
      "metadata": {},
@@ -291,7 +319,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "(36, 162, 163, 165, 8364, 164)"
+      "text/plain": [
+       "(36, 162, 163, 165, 8364, 164)"
+      ]
      },
      "execution_count": 11,
      "metadata": {},
@@ -310,7 +340,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "array('I', [36, 162, 163, 165, 8364, 164])"
+      "text/plain": [
+       "array('I', [36, 162, 163, 165, 8364, 164])"
+      ]
      },
      "execution_count": 12,
      "metadata": {},
@@ -358,32 +390,37 @@
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "## Tuples Are Not Just Immutable Lists"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
    },
-   "execution_count": 73
+   "source": [
+    "## Tuples Are Not Just Immutable Lists"
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "#### Example 2-7. Tuples used as records"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "#### Example 2-7. Tuples used as records"
+   ]
   },
   {
    "cell_type": "code",
    "execution_count": 14,
+   "metadata": {
+    "collapsed": false,
+    "pycharm": {
+     "name": "#%%\n"
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -402,17 +439,17 @@
     "\n",
     "for passport in sorted(traveler_ids):\n",
     "    print('%s/%s' % passport)"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -427,33 +464,35 @@
    "source": [
     "for country, _ in traveler_ids:\n",
     "    print(country)"
-   ],
-   "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
-   }
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "### Tuples as Immutable Lists"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "### Tuples as Immutable Lists"
+   ]
   },
   {
    "cell_type": "code",
    "execution_count": 16,
+   "metadata": {
+    "collapsed": false,
+    "pycharm": {
+     "name": "#%%\n"
+    }
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "True"
+      "text/plain": [
+       "True"
+      ]
      },
      "execution_count": 16,
      "metadata": {},
@@ -464,21 +503,23 @@
     "a = (10, 'alpha', [1, 2])\n",
     "b = (10, 'alpha', [1, 2])\n",
     "a == b"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 17,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "False"
+      "text/plain": [
+       "False"
+      ]
      },
      "execution_count": 17,
      "metadata": {},
@@ -488,21 +529,23 @@
    "source": [
     "b[-1].append(99)\n",
     "a == b"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 18,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(10, 'alpha', [1, 2, 99])"
+      "text/plain": [
+       "(10, 'alpha', [1, 2, 99])"
+      ]
      },
      "execution_count": 18,
      "metadata": {},
@@ -511,21 +554,23 @@
    ],
    "source": [
     "b"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 19,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "True"
+      "text/plain": [
+       "True"
+      ]
      },
      "execution_count": 19,
      "metadata": {},
@@ -544,21 +589,23 @@
     "tf = (10, 'alpha', (1, 2))  # Contains no mutable items\n",
     "tm = (10, 'alpha', [1, 2])  # Contains a mutable item (list)\n",
     "fixed(tf)"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 20,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 20,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "False"
+      "text/plain": [
+       "False"
+      ]
      },
      "execution_count": 20,
      "metadata": {},
@@ -567,35 +614,37 @@
    ],
    "source": [
     "fixed(tm)"
-   ],
-   "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
-   }
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "## Unpacking sequences and iterables"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "## Unpacking sequences and iterables"
+   ]
   },
   {
    "cell_type": "code",
-   "execution_count": 21,
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false,
+    "pycharm": {
+     "name": "#%%\n"
+    }
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "33.9425"
+      "text/plain": [
+       "33.9425"
+      ]
      },
-     "execution_count": 21,
+     "execution_count": 2,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -604,44 +653,48 @@
     "lax_coordinates = (33.9425, -118.408056)\n",
     "latitude, longitude = lax_coordinates  # unpacking\n",
     "latitude"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 22,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "-118.408056"
+      "text/plain": [
+       "-118.408056"
+      ]
      },
-     "execution_count": 22,
+     "execution_count": 3,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
     "longitude"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 23,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 23,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(2, 4)"
+      "text/plain": [
+       "(2, 4)"
+      ]
      },
      "execution_count": 23,
      "metadata": {},
@@ -650,21 +703,23 @@
    ],
    "source": [
     "divmod(20, 8)"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 24,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 24,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(2, 4)"
+      "text/plain": [
+       "(2, 4)"
+      ]
      },
      "execution_count": 24,
      "metadata": {},
@@ -674,21 +729,23 @@
    "source": [
     "t = (20, 8)\n",
     "divmod(*t)"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 25,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 25,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(2, 4)"
+      "text/plain": [
+       "(2, 4)"
+      ]
      },
      "execution_count": 25,
      "metadata": {},
@@ -698,21 +755,23 @@
    "source": [
     "quotient, remainder = divmod(*t)\n",
     "quotient, remainder"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 26,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 26,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "'id_rsa.pub'"
+      "text/plain": [
+       "'id_rsa.pub'"
+      ]
      },
      "execution_count": 26,
      "metadata": {},
@@ -724,33 +783,35 @@
     "\n",
     "_, filename = os.path.split('/home/luciano/.ssh/id_rsa.pub')\n",
     "filename"
-   ],
-   "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
-   }
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "### Using * to grab excess items"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "### Using * to grab excess items"
+   ]
   },
   {
    "cell_type": "code",
    "execution_count": 27,
+   "metadata": {
+    "collapsed": false,
+    "pycharm": {
+     "name": "#%%\n"
+    }
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(0, 1, [2, 3, 4])"
+      "text/plain": [
+       "(0, 1, [2, 3, 4])"
+      ]
      },
      "execution_count": 27,
      "metadata": {},
@@ -760,21 +821,23 @@
    "source": [
     "a, b, *rest = range(5)\n",
     "a, b, rest"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 28,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(0, 1, [2])"
+      "text/plain": [
+       "(0, 1, [2])"
+      ]
      },
      "execution_count": 28,
      "metadata": {},
@@ -784,21 +847,23 @@
    "source": [
     "a, b, *rest = range(3)\n",
     "a, b, rest"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 29,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 29,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(0, 1, [])"
+      "text/plain": [
+       "(0, 1, [])"
+      ]
      },
      "execution_count": 29,
      "metadata": {},
@@ -808,21 +873,23 @@
    "source": [
     "a, b, *rest = range(2)\n",
     "a, b, rest"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 30,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 30,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(0, [1, 2], 3, 4)"
+      "text/plain": [
+       "(0, [1, 2], 3, 4)"
+      ]
      },
      "execution_count": 30,
      "metadata": {},
@@ -832,21 +899,23 @@
    "source": [
     "a, *body, c, d = range(5)\n",
     "a, body, c, d"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 31,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 31,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "([0, 1], 2, 3, 4)"
+      "text/plain": [
+       "([0, 1], 2, 3, 4)"
+      ]
      },
      "execution_count": 31,
      "metadata": {},
@@ -856,33 +925,35 @@
    "source": [
     "*head, b, c, d = range(5)\n",
     "head, b, c, d"
-   ],
-   "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
-   }
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "### Unpacking with * in function calls and sequence literals"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "### Unpacking with * in function calls and sequence literals"
+   ]
   },
   {
    "cell_type": "code",
    "execution_count": 32,
+   "metadata": {
+    "collapsed": false,
+    "pycharm": {
+     "name": "#%%\n"
+    }
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(1, 2, 3, 4, (5, 6))"
+      "text/plain": [
+       "(1, 2, 3, 4, (5, 6))"
+      ]
      },
      "execution_count": 32,
      "metadata": {},
@@ -895,21 +966,23 @@
     "\n",
     "\n",
     "fun(*[1, 2], 3, *range(4, 7))"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 33,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 33,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "(0, 1, 2, 3, 4)"
+      "text/plain": [
+       "(0, 1, 2, 3, 4)"
+      ]
      },
      "execution_count": 33,
      "metadata": {},
@@ -918,21 +991,23 @@
    ],
    "source": [
     "*range(4), 4"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 34,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 34,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "[0, 1, 2, 3, 4]"
+      "text/plain": [
+       "[0, 1, 2, 3, 4]"
+      ]
      },
      "execution_count": 34,
      "metadata": {},
@@ -941,21 +1016,23 @@
    ],
    "source": [
     "[*range(4), 4]"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 35,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 35,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "{0, 1, 2, 3, 4, 5, 6, 7}"
+      "text/plain": [
+       "{0, 1, 2, 3, 4, 5, 6, 7}"
+      ]
      },
      "execution_count": 35,
      "metadata": {},
@@ -964,45 +1041,45 @@
    ],
    "source": [
     "{*range(4), 4, *(5, 6, 7)}"
-   ],
+   ]
+  },
+  {
+   "cell_type": "markdown",
    "metadata": {
     "collapsed": false,
     "pycharm": {
-     "name": "#%%\n"
+     "name": "#%% md\n"
     }
-   }
-  },
-  {
-   "cell_type": "markdown",
+   },
    "source": [
     "### Nested unpacking\n",
     "#### Example 2-8. Unpacking nested tuples to access the longitude\n",
     "\n",
     "[02-array-seq/metro_lat_lon.py](02-array-seq/metro_lat_lon.py)"
-   ],
-   "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%% md\n"
-    }
-   }
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "## Pattern Matching with Sequences\n",
-    "#### Example 2-9. Method from an imaginary Robot class"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "## Pattern Matching with Sequences\n",
+    "#### Example 2-9. Method from an imaginary Robot class"
+   ]
   },
   {
    "cell_type": "code",
    "execution_count": 36,
+   "metadata": {
+    "collapsed": false,
+    "pycharm": {
+     "name": "#%%\n"
+    }
+   },
    "outputs": [],
    "source": [
     "# def handle_command(self, message):\n",
@@ -1017,30 +1094,30 @@
     "#             self.leds[ident].set_color(ident, red, green, blue)\n",
     "#         case _:\n",
     "#             raise InvalidCommand(message)"
-   ],
-   "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
-   }
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "#### Example 2-10. Destructuring nested tuples—requires Python ≥ 3.10.\n",
-    "[02-array-seq/match_lat_lon.py](02-array-seq/match_lat_lon.py)"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "#### Example 2-10. Destructuring nested tuples—requires Python ≥ 3.10.\n",
+    "[02-array-seq/match_lat_lon.py](02-array-seq/match_lat_lon.py)"
+   ]
   },
   {
    "cell_type": "code",
    "execution_count": 37,
+   "metadata": {
+    "collapsed": false,
+    "pycharm": {
+     "name": "#%%\n"
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -1069,57 +1146,51 @@
     "            case [name, _, _, (lat, lon)] if lon <= 0:\n",
     "                print(f'{name:15} | {lat:9.4f} | {lon:9.4f}')\n",
     "main()"
-   ],
-   "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
-   }
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": []
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "### Pattern Matching Sequences in an Interpreter\n",
-    "#### Example 2-11. Matching patterns without match/case.\n",
-    "[02-array-seq/lispy/py3.9/lis.py](02-array-seq/lispy/py3.9/lis.py)"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "### Pattern Matching Sequences in an Interpreter\n",
+    "#### Example 2-11. Matching patterns without match/case.\n",
+    "[02-array-seq/lispy/py3.9/lis.py](02-array-seq/lispy/py3.9/lis.py)"
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "#### Example 2-12. Pattern matching with match/case—requires Python ≥ 3.10.\n",
-    "[02-array-seq/lispy/py3.10/lis.py](02-array-seq/lispy/py3.10/lis.py)"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "#### Example 2-12. Pattern matching with match/case—requires Python ≥ 3.10.\n",
+    "[02-array-seq/lispy/py3.10/lis.py](02-array-seq/lispy/py3.10/lis.py)"
+   ]
   },
   {
    "cell_type": "markdown",
-   "source": [],
    "metadata": {
     "collapsed": false
-   }
+   },
+   "source": []
   },
   {
    "cell_type": "markdown",
@@ -1142,7 +1213,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[10, 20]"
+      "text/plain": [
+       "[10, 20]"
+      ]
      },
      "execution_count": 38,
      "metadata": {},
@@ -1162,7 +1235,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[30, 40, 50, 60]"
+      "text/plain": [
+       "[30, 40, 50, 60]"
+      ]
      },
      "execution_count": 39,
      "metadata": {},
@@ -1180,7 +1255,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[10, 20, 30]"
+      "text/plain": [
+       "[10, 20, 30]"
+      ]
      },
      "execution_count": 40,
      "metadata": {},
@@ -1198,7 +1275,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[40, 50, 60]"
+      "text/plain": [
+       "[40, 50, 60]"
+      ]
      },
      "execution_count": 41,
      "metadata": {},
@@ -1223,7 +1302,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "'bye'"
+      "text/plain": [
+       "'bye'"
+      ]
      },
      "execution_count": 42,
      "metadata": {},
@@ -1242,7 +1323,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "'elcycib'"
+      "text/plain": [
+       "'elcycib'"
+      ]
      },
      "execution_count": 43,
      "metadata": {},
@@ -1260,7 +1343,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "'eccb'"
+      "text/plain": [
+       "'eccb'"
+      ]
      },
      "execution_count": 44,
      "metadata": {},
@@ -1330,7 +1415,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]"
+      "text/plain": [
+       "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]"
+      ]
      },
      "execution_count": 46,
      "metadata": {},
@@ -1349,7 +1436,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[0, 1, 20, 30, 5, 6, 7, 8, 9]"
+      "text/plain": [
+       "[0, 1, 20, 30, 5, 6, 7, 8, 9]"
+      ]
      },
      "execution_count": 47,
      "metadata": {},
@@ -1368,7 +1457,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[0, 1, 20, 30, 5, 8, 9]"
+      "text/plain": [
+       "[0, 1, 20, 30, 5, 8, 9]"
+      ]
      },
      "execution_count": 48,
      "metadata": {},
@@ -1387,7 +1478,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[0, 1, 20, 11, 5, 22, 9]"
+      "text/plain": [
+       "[0, 1, 20, 11, 5, 22, 9]"
+      ]
      },
      "execution_count": 49,
      "metadata": {},
@@ -1433,7 +1526,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[0, 1, 100, 22, 9]"
+      "text/plain": [
+       "[0, 1, 100, 22, 9]"
+      ]
      },
      "execution_count": 51,
      "metadata": {},
@@ -1459,7 +1554,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3]"
+      "text/plain": [
+       "[1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3]"
+      ]
      },
      "execution_count": 52,
      "metadata": {},
@@ -1478,7 +1575,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "'abcdabcdabcdabcdabcd'"
+      "text/plain": [
+       "'abcdabcdabcdabcdabcd'"
+      ]
      },
      "execution_count": 53,
      "metadata": {},
@@ -1510,7 +1609,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[['_', '_', '_'], ['_', '_', '_'], ['_', '_', '_']]"
+      "text/plain": [
+       "[['_', '_', '_'], ['_', '_', '_'], ['_', '_', '_']]"
+      ]
      },
      "execution_count": 54,
      "metadata": {},
@@ -1529,7 +1630,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[['_', '_', '_'], ['_', '_', 'X'], ['_', '_', '_']]"
+      "text/plain": [
+       "[['_', '_', '_'], ['_', '_', 'X'], ['_', '_', '_']]"
+      ]
      },
      "execution_count": 55,
      "metadata": {},
@@ -1555,7 +1658,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[['_', '_', '_'], ['_', '_', '_'], ['_', '_', '_']]"
+      "text/plain": [
+       "[['_', '_', '_'], ['_', '_', '_'], ['_', '_', '_']]"
+      ]
      },
      "execution_count": 56,
      "metadata": {},
@@ -1574,7 +1679,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[['_', '_', 'O'], ['_', '_', 'O'], ['_', '_', 'O']]"
+      "text/plain": [
+       "[['_', '_', 'O'], ['_', '_', 'O'], ['_', '_', 'O']]"
+      ]
      },
      "execution_count": 57,
      "metadata": {},
@@ -1600,7 +1707,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[['_', '_', '_'], ['_', '_', '_'], ['_', '_', '_']]"
+      "text/plain": [
+       "[['_', '_', '_'], ['_', '_', '_'], ['_', '_', '_']]"
+      ]
      },
      "execution_count": 58,
      "metadata": {},
@@ -1622,7 +1731,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[['_', '_', '_'], ['_', '_', '_'], ['X', '_', '_']]"
+      "text/plain": [
+       "[['_', '_', '_'], ['_', '_', '_'], ['X', '_', '_']]"
+      ]
      },
      "execution_count": 59,
      "metadata": {},
@@ -1643,7 +1754,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 60,
+   "execution_count": 1,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1653,14 +1764,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 61,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [
     {
      "data": {
-      "text/plain": "140694277263808"
+      "text/plain": [
+       "137958310687616"
+      ]
      },
-     "execution_count": 61,
+     "execution_count": 2,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1672,14 +1785,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 62,
+   "execution_count": 3,
    "metadata": {},
    "outputs": [
     {
      "data": {
-      "text/plain": "[1, 2, 3, 1, 2, 3]"
+      "text/plain": [
+       "[1, 2, 3, 1, 2, 3]"
+      ]
      },
-     "execution_count": 62,
+     "execution_count": 3,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1691,14 +1806,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 63,
+   "execution_count": 4,
    "metadata": {},
    "outputs": [
     {
      "data": {
-      "text/plain": "True"
+      "text/plain": [
+       "True"
+      ]
      },
-     "execution_count": 63,
+     "execution_count": 4,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1724,7 +1841,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "140694329335488"
+      "text/plain": [
+       "140694329335488"
+      ]
      },
      "execution_count": 65,
      "metadata": {},
@@ -1743,7 +1862,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "False"
+      "text/plain": [
+       "False"
+      ]
      },
      "execution_count": 66,
      "metadata": {},
@@ -1786,15 +1907,15 @@
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "#### Example 2-17. The unexpected result: item t2 is changed and an exception is raised"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "#### Example 2-17. The unexpected result: item t2 is changed and an exception is raised"
+   ]
   },
   {
    "cell_type": "code",
@@ -1803,7 +1924,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "(1, 2, [30, 40, 50, 60])"
+      "text/plain": [
+       "(1, 2, [30, 40, 50, 60])"
+      ]
      },
      "execution_count": 68,
      "metadata": {},
@@ -1863,7 +1986,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "['apple', 'banana', 'grape', 'raspberry']"
+      "text/plain": [
+       "['apple', 'banana', 'grape', 'raspberry']"
+      ]
      },
      "execution_count": 70,
      "metadata": {},
@@ -1882,7 +2007,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "['grape', 'raspberry', 'apple', 'banana']"
+      "text/plain": [
+       "['grape', 'raspberry', 'apple', 'banana']"
+      ]
      },
      "execution_count": 71,
      "metadata": {},
@@ -1900,7 +2027,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "['raspberry', 'grape', 'banana', 'apple']"
+      "text/plain": [
+       "['raspberry', 'grape', 'banana', 'apple']"
+      ]
      },
      "execution_count": 72,
      "metadata": {},
@@ -1918,7 +2047,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "['grape', 'apple', 'banana', 'raspberry']"
+      "text/plain": [
+       "['grape', 'apple', 'banana', 'raspberry']"
+      ]
      },
      "execution_count": 73,
      "metadata": {},
@@ -1936,7 +2067,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "['raspberry', 'banana', 'grape', 'apple']"
+      "text/plain": [
+       "['raspberry', 'banana', 'grape', 'apple']"
+      ]
      },
      "execution_count": 74,
      "metadata": {},
@@ -1954,7 +2087,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "['grape', 'raspberry', 'apple', 'banana']"
+      "text/plain": [
+       "['grape', 'raspberry', 'apple', 'banana']"
+      ]
      },
      "execution_count": 75,
      "metadata": {},
@@ -1972,7 +2107,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "['apple', 'banana', 'grape', 'raspberry']"
+      "text/plain": [
+       "['apple', 'banana', 'grape', 'raspberry']"
+      ]
      },
      "execution_count": 76,
      "metadata": {},
@@ -2007,24 +2144,25 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 77,
+   "execution_count": 6,
    "metadata": {},
    "outputs": [
     {
      "data": {
-      "text/plain": "0.8190492979077034"
+      "text/plain": [
+       "0.6624367771747223"
+      ]
      },
-     "execution_count": 77,
+     "execution_count": 6,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
     "from array import array\n",
-    "from random import random, seed\n",
-    "seed(10)  # Use seed to make the output consistent\n",
+    "from random import random\n",
     "\n",
-    "floats = array('d', (random() for i in range(10 ** 7)))\n",
+    "floats = array('d', (random() for i in (range(10**7))))\n",
     "floats[-1]"
    ]
   },
@@ -2045,7 +2183,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "0.8190492979077034"
+      "text/plain": [
+       "0.8190492979077034"
+      ]
      },
      "execution_count": 79,
      "metadata": {},
@@ -2068,7 +2208,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "True"
+      "text/plain": [
+       "True"
+      ]
      },
      "execution_count": 80,
      "metadata": {},
@@ -2088,23 +2230,31 @@
   },
   {
    "cell_type": "markdown",
-   "source": [
-    "#### Example 2-20. Handling 6 bytes memory of as 1×6, 2×3, and 3×2 views"
-   ],
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%% md\n"
     }
-   }
+   },
+   "source": [
+    "#### Example 2-20. Handling 6 bytes memory of as 1×6, 2×3, and 3×2 views"
+   ]
   },
   {
    "cell_type": "code",
    "execution_count": 81,
+   "metadata": {
+    "collapsed": false,
+    "pycharm": {
+     "name": "#%%\n"
+    }
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "[0, 1, 2, 3, 4, 5]"
+      "text/plain": [
+       "[0, 1, 2, 3, 4, 5]"
+      ]
      },
      "execution_count": 81,
      "metadata": {},
@@ -2115,21 +2265,23 @@
     "octets = array('B', range(6))\n",
     "m1 = memoryview(octets)\n",
     "m1.tolist()"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 82,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 82,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "[[0, 1, 2], [3, 4, 5]]"
+      "text/plain": [
+       "[[0, 1, 2], [3, 4, 5]]"
+      ]
      },
      "execution_count": 82,
      "metadata": {},
@@ -2139,21 +2291,23 @@
    "source": [
     "m2 = m1.cast('B', [2, 3])\n",
     "m2.tolist()"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 83,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 83,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "[[0, 1], [2, 3], [4, 5]]"
+      "text/plain": [
+       "[[0, 1], [2, 3], [4, 5]]"
+      ]
      },
      "execution_count": 83,
      "metadata": {},
@@ -2163,21 +2317,23 @@
    "source": [
     "m3 = m1.cast('B', [3, 2])\n",
     "m3.tolist()"
-   ],
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 84,
    "metadata": {
     "collapsed": false,
     "pycharm": {
      "name": "#%%\n"
     }
-   }
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 84,
+   },
    "outputs": [
     {
      "data": {
-      "text/plain": "array('B', [0, 1, 2, 33, 22, 5])"
+      "text/plain": [
+       "array('B', [0, 1, 2, 33, 22, 5])"
+      ]
      },
      "execution_count": 84,
      "metadata": {},
@@ -2188,13 +2344,7 @@
     "m2[1,1] = 22\n",
     "m3[1,1] = 33\n",
     "octets"
-   ],
-   "metadata": {
-    "collapsed": false,
-    "pycharm": {
-     "name": "#%%\n"
-    }
-   }
+   ]
   },
   {
    "cell_type": "markdown",
@@ -2210,7 +2360,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "5"
+      "text/plain": [
+       "5"
+      ]
      },
      "execution_count": 85,
      "metadata": {},
@@ -2230,7 +2382,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "-2"
+      "text/plain": [
+       "-2"
+      ]
      },
      "execution_count": 86,
      "metadata": {},
@@ -2248,7 +2402,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[254, 255, 255, 255, 0, 0, 1, 0, 2, 0]"
+      "text/plain": [
+       "[254, 255, 255, 255, 0, 0, 1, 0, 2, 0]"
+      ]
      },
      "execution_count": 87,
      "metadata": {},
@@ -2267,7 +2423,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "array('h', [-2, -1, 1024, 1, 2])"
+      "text/plain": [
+       "array('h', [-2, -1, 1024, 1, 2])"
+      ]
      },
      "execution_count": 88,
      "metadata": {},
@@ -2300,7 +2458,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11])"
+      "text/plain": [
+       "array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11])"
+      ]
      },
      "execution_count": 89,
      "metadata": {},
@@ -2321,7 +2481,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "numpy.ndarray"
+      "text/plain": [
+       "numpy.ndarray"
+      ]
      },
      "execution_count": 90,
      "metadata": {},
@@ -2339,7 +2501,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "(12,)"
+      "text/plain": [
+       "(12,)"
+      ]
      },
      "execution_count": 91,
      "metadata": {},
@@ -2357,7 +2521,11 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "array([[ 0,  1,  2,  3],\n       [ 4,  5,  6,  7],\n       [ 8,  9, 10, 11]])"
+      "text/plain": [
+       "array([[ 0,  1,  2,  3],\n",
+       "       [ 4,  5,  6,  7],\n",
+       "       [ 8,  9, 10, 11]])"
+      ]
      },
      "execution_count": 92,
      "metadata": {},
@@ -2376,7 +2544,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "array([ 8,  9, 10, 11])"
+      "text/plain": [
+       "array([ 8,  9, 10, 11])"
+      ]
      },
      "execution_count": 93,
      "metadata": {},
@@ -2394,7 +2564,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "9"
+      "text/plain": [
+       "9"
+      ]
      },
      "execution_count": 94,
      "metadata": {},
@@ -2412,7 +2584,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "array([1, 5, 9])"
+      "text/plain": [
+       "array([1, 5, 9])"
+      ]
      },
      "execution_count": 95,
      "metadata": {},
@@ -2430,7 +2604,12 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "array([[ 0,  4,  8],\n       [ 1,  5,  9],\n       [ 2,  6, 10],\n       [ 3,  7, 11]])"
+      "text/plain": [
+       "array([[ 0,  4,  8],\n",
+       "       [ 1,  5,  9],\n",
+       "       [ 2,  6, 10],\n",
+       "       [ 3,  7, 11]])"
+      ]
      },
      "execution_count": 96,
      "metadata": {},
@@ -2475,7 +2654,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "array([0.06078257, 0.61741189, 0.84349987])"
+      "text/plain": [
+       "array([0.06078257, 0.61741189, 0.84349987])"
+      ]
      },
      "execution_count": 99,
      "metadata": {},
@@ -2493,7 +2674,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "array([0.03039128, 0.30870594, 0.42174994])"
+      "text/plain": [
+       "array([0.03039128, 0.30870594, 0.42174994])"
+      ]
      },
      "execution_count": 100,
      "metadata": {},
@@ -2512,7 +2695,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "True"
+      "text/plain": [
+       "True"
+      ]
      },
      "execution_count": 101,
      "metadata": {},
@@ -2545,7 +2730,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "memmap([0.06078257, 0.61741189, 0.84349987])"
+      "text/plain": [
+       "memmap([0.06078257, 0.61741189, 0.84349987])"
+      ]
      },
      "execution_count": 103,
      "metadata": {},
@@ -2572,22 +2759,24 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 104,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [
     {
      "data": {
-      "text/plain": "deque([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])"
+      "text/plain": [
+       "deque([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], maxlen=10)"
+      ]
      },
-     "execution_count": 104,
+     "execution_count": 2,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "import collections\n",
+    "from collections import deque\n",
     "\n",
-    "dq = collections.deque(range(10), maxlen=10)\n",
+    "dq = deque(range(10), maxlen=10)\n",
     "dq"
    ]
   },
@@ -2598,7 +2787,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "deque([7, 8, 9, 0, 1, 2, 3, 4, 5, 6])"
+      "text/plain": [
+       "deque([7, 8, 9, 0, 1, 2, 3, 4, 5, 6])"
+      ]
      },
      "execution_count": 105,
      "metadata": {},
@@ -2617,7 +2808,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "deque([1, 2, 3, 4, 5, 6, 7, 8, 9, 0])"
+      "text/plain": [
+       "deque([1, 2, 3, 4, 5, 6, 7, 8, 9, 0])"
+      ]
      },
      "execution_count": 106,
      "metadata": {},
@@ -2636,7 +2829,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "deque([-1, 1, 2, 3, 4, 5, 6, 7, 8, 9])"
+      "text/plain": [
+       "deque([-1, 1, 2, 3, 4, 5, 6, 7, 8, 9])"
+      ]
      },
      "execution_count": 107,
      "metadata": {},
@@ -2655,7 +2850,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "deque([3, 4, 5, 6, 7, 8, 9, 11, 22, 33])"
+      "text/plain": [
+       "deque([3, 4, 5, 6, 7, 8, 9, 11, 22, 33])"
+      ]
      },
      "execution_count": 108,
      "metadata": {},
@@ -2674,7 +2871,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "deque([40, 30, 20, 10, 3, 4, 5, 6, 7, 8])"
+      "text/plain": [
+       "deque([40, 30, 20, 10, 3, 4, 5, 6, 7, 8])"
+      ]
      },
      "execution_count": 109,
      "metadata": {},
@@ -2743,7 +2942,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[0, '1', 5, 6, '9', 14, 19, '23', 28, '28']"
+      "text/plain": [
+       "[0, '1', 5, 6, '9', 14, 19, '23', 28, '28']"
+      ]
      },
      "execution_count": 112,
      "metadata": {},
@@ -2763,7 +2964,9 @@
    "outputs": [
     {
      "data": {
-      "text/plain": "[0, '1', 14, 19, '23', 28, '28', 5, 6, '9']"
+      "text/plain": [
+       "[0, '1', 14, 19, '23', 28, '28', 5, 6, '9']"
+      ]
      },
      "execution_count": 113,
      "metadata": {},
@@ -2773,18 +2976,11 @@
    "source": [
     "sorted(l, key=str)"
    ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 113,
-   "metadata": {},
-   "outputs": [],
-   "source": []
   }
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3",
+   "display_name": "base",
    "language": "python",
    "name": "python3"
   },
@@ -2798,9 +2994,9 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.0"
+   "version": "3.13.2"
   }
  },
  "nbformat": 4,
  "nbformat_minor": 2
-}
\ No newline at end of file
+}
diff --git a/03-dict-set/03-dict-set-my.ipynb b/03-dict-set/03-dict-set-my.ipynb
new file mode 100644
index 0000000..00cfb2f
--- /dev/null
+++ b/03-dict-set/03-dict-set-my.ipynb
@@ -0,0 +1,98 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "07b0ec1a",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{'Bangladesh': 880,\n",
+       " 'Brazil': 55,\n",
+       " 'China': 86,\n",
+       " 'India': 91,\n",
+       " 'Indonesia': 62,\n",
+       " 'Japan': 81,\n",
+       " 'Nigeria': 234,\n",
+       " 'Pakistan': 92,\n",
+       " 'Russia': 7,\n",
+       " 'United States': 1}"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "dial_codes = [                                                  # <1>\n",
+    "    (880, 'Bangladesh'),\n",
+    "    (55,  'Brazil'),\n",
+    "    (86,  'China'),\n",
+    "    (91,  'India'),\n",
+    "    (62,  'Indonesia'),\n",
+    "    (81,  'Japan'),\n",
+    "    (234, 'Nigeria'),\n",
+    "    (92,  'Pakistan'),\n",
+    "    (7,   'Russia'),\n",
+    "    (1,   'United States'),\n",
+    "]\n",
+    "\n",
+    "country_dial = {country : code for code, country in dial_codes}\n",
+    "country_dial"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "a62fe850",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{55: 'BRAZIL', 62: 'INDONESIA', 7: 'RUSSIA', 1: 'UNITED STATES'}"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "{code : country.upper() for country, code in sorted(country_dial.items()) if code < 70}"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "c1e2537f",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "base",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.13.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}
diff --git a/03-dict-set/03-dict-set.ipynb b/03-dict-set/03-dict-set.ipynb
index 1bfc9d5..c15dc72 100644
--- a/03-dict-set/03-dict-set.ipynb
+++ b/03-dict-set/03-dict-set.ipynb
@@ -9,8 +9,7 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "3.8.0 (v3.8.0:fa919fdf25, Oct 14 2019, 10:23:27) \n",
-      "[Clang 6.0 (clang-600.0.57)]\n"
+      "3.13.2 | packaged by Anaconda, Inc. | (main, Feb  6 2025, 18:56:02) [GCC 11.2.0]\n"
      ]
     }
    ],
@@ -363,7 +362,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3",
+   "display_name": "base",
    "language": "python",
    "name": "python3"
   },
@@ -377,7 +376,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.0"
+   "version": "3.13.2"
   }
  },
  "nbformat": 4,
diff --git a/06-obj-ref/06-obj-ref-my.ipynb b/06-obj-ref/06-obj-ref-my.ipynb
new file mode 100644
index 0000000..e8c077e
--- /dev/null
+++ b/06-obj-ref/06-obj-ref-my.ipynb
@@ -0,0 +1,160 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "b3d69b0c",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Gizmo:\n",
+    "    def __init__(self):\n",
+    "        print(f'Gizmo id: {id(self)}')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "eab650d2",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Gizmo id: 139964324471744\n"
+     ]
+    }
+   ],
+   "source": [
+    "x = Gizmo()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "f75f36ac",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Gizmo id: 139964314373008\n"
+     ]
+    },
+    {
+     "ename": "TypeError",
+     "evalue": "unsupported operand type(s) for *: 'Gizmo' and 'int'",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[31m---------------------------------------------------------------------------\u001b[39m",
+      "\u001b[31mTypeError\u001b[39m                                 Traceback (most recent call last)",
+      "\u001b[36mCell\u001b[39m\u001b[36m \u001b[39m\u001b[32mIn[4]\u001b[39m\u001b[32m, line 1\u001b[39m\n\u001b[32m----> \u001b[39m\u001b[32m1\u001b[39m y = \u001b[43mGizmo\u001b[49m\u001b[43m(\u001b[49m\u001b[43m)\u001b[49m\u001b[43m \u001b[49m\u001b[43m*\u001b[49m\u001b[43m \u001b[49m\u001b[32;43m10\u001b[39;49m\n",
+      "\u001b[31mTypeError\u001b[39m: unsupported operand type(s) for *: 'Gizmo' and 'int'"
+     ]
+    }
+   ],
+   "source": [
+    "y = Gizmo() * 10"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "f5e9be8f",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "dir()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "f3c9ed77",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[[10, 20, [...]], 30]"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "a = [10, 20]\n",
+    "b = [a, 30]\n",
+    "a.append(b)\n",
+    "\n",
+    "b"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "23a0d99a",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "a = [1, 2]\n",
+    "b = a"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "9393ddd4",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[1, 2]"
+      ]
+     },
+     "execution_count": 8,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "del a\n",
+    "b"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "3a47d1a1",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "base",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.13.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}
diff --git a/07-1class-func/07-1class-func-my.ipynb b/07-1class-func/07-1class-func-my.ipynb
new file mode 100644
index 0000000..d9f9e3d
--- /dev/null
+++ b/07-1class-func/07-1class-func-my.ipynb
@@ -0,0 +1,108 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "73e3c67e",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def factorial(n):\n",
+    "    \"\"\"returns n!\"\"\"\n",
+    "    return 1 if n < 2 else n * factorial(n - 1)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "d6376226",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "1405006117752879898543142606244511569936384000000000"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "factorial(42)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "675ab80f",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'returns n!'"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "factorial.__doc__"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "fdc84af6",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "function"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "type(factorial)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "dd1595a0",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "base",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.13.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}
diff --git a/07-1class-func/birds.py b/07-1class-func/birds.py
new file mode 100644
index 0000000..8ecbe41
--- /dev/null
+++ b/07-1class-func/birds.py
@@ -0,0 +1,15 @@
+class Bird:
+    pass
+
+class Duck(Bird):
+    def quack(self):
+        print('quack')
+
+def alert(birdie):
+    birdie.quack()
+
+def alert_duck(birdie: Duck) -> None:
+    birdie.quack()
+
+def alert_bird(birdie: Bird) -> None:
+    birdie.quack()
diff --git a/09-closure-deco/09-closure-deco-my.ipynb b/09-closure-deco/09-closure-deco-my.ipynb
new file mode 100644
index 0000000..5cc2638
--- /dev/null
+++ b/09-closure-deco/09-closure-deco-my.ipynb
@@ -0,0 +1,567 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "6cee2756",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def deco(func):\n",
+    "    def inner():\n",
+    "        print('running inner()')\n",
+    "    return inner"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "c52aaa2d",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "@deco\n",
+    "def target():\n",
+    "    print('running target()')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "3cc80516",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "running inner()\n"
+     ]
+    }
+   ],
+   "source": [
+    "target()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "db6646aa",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "<function __main__.deco.<locals>.inner()>"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "target"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "346c8343",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Averager():\n",
+    "    def __init__(self):\n",
+    "        self.series = []\n",
+    "    \n",
+    "    def __call__(self, new_value):\n",
+    "        self.series.append(new_value)\n",
+    "        total = sum(self.series)\n",
+    "        return total / len(self.series)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "bc863bf5",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "10.0"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "avg = Averager()\n",
+    "avg(10)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "3a0b2c4c",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "10.5"
+      ]
+     },
+     "execution_count": 7,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "avg(11)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "8d022e82",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "11.0"
+      ]
+     },
+     "execution_count": 8,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "avg(12)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "id": "22a8f9d5",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def make_averager():\n",
+    "    series = []\n",
+    "\n",
+    "    def averager(new_value):\n",
+    "        series.append(new_value)\n",
+    "        total = sum(series)\n",
+    "        return total / len(series)\n",
+    "    \n",
+    "    return averager"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "id": "9203d6b2",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "10.0"
+      ]
+     },
+     "execution_count": 10,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "avg = make_averager()\n",
+    "avg(10)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "id": "09169a7f",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "10.5"
+      ]
+     },
+     "execution_count": 11,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "avg(11)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "id": "c44a4383",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "12.0"
+      ]
+     },
+     "execution_count": 12,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "avg(15)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "id": "6eab0680",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def make_averager():\n",
+    "    total = 0\n",
+    "    length = 0\n",
+    "\n",
+    "    def averager(new_value):\n",
+    "        nonlocal total\n",
+    "        nonlocal length\n",
+    "\n",
+    "        total += new_value\n",
+    "        length += 1\n",
+    "        return total / length\n",
+    "    \n",
+    "    return averager"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "id": "5c00b091",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "10.0"
+      ]
+     },
+     "execution_count": 16,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "avg = make_averager()\n",
+    "avg(10)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 17,
+   "id": "072a66a3",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "10.5"
+      ]
+     },
+     "execution_count": 17,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "avg(11)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "id": "bdc46456",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "12.0"
+      ]
+     },
+     "execution_count": 18,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "avg(15)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "f926e541",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import time\n",
+    "\n",
+    "def clock(func):\n",
+    "    def clocked(*args):\n",
+    "        t0 = time.perf_counter()\n",
+    "        result = func(*args)\n",
+    "        elapsted = time.perf_counter() - t0\n",
+    "        name = func.__name__\n",
+    "        arg_str = ', '.join(repr(arg) for arg in args)\n",
+    "        print(f'[{elapsted:0.8f}s] {name}({arg_str}) -> {result!r}')\n",
+    "        return result\n",
+    "    return clocked"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "15ac74f4",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "@clock\n",
+    "def snooze(seconds):\n",
+    "    time.sleep(seconds)\n",
+    "\n",
+    "@clock\n",
+    "def factorial(n):\n",
+    "    return 1 if n < 2 else n*factorial(n-1)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "10bf5f1d",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "[0.12314337s] snooze(0.123) -> None\n"
+     ]
+    }
+   ],
+   "source": [
+    "snooze(.123)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "1cd74b55",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "[0.00000185s] factorial(1) -> 1\n",
+      "[0.00015414s] factorial(2) -> 2\n",
+      "[0.00024095s] factorial(3) -> 6\n",
+      "[0.00029704s] factorial(4) -> 24\n",
+      "[0.00031943s] factorial(5) -> 120\n",
+      "[0.00033855s] factorial(6) -> 720\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "720"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "factorial(6)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "7dff9dd7",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import time\n",
+    "import functools\n",
+    "\n",
+    "def clock(func):\n",
+    "    @functools.wraps(func)\n",
+    "    def clocked(*args, **kwargs):\n",
+    "        t0 = time.perf_counter()\n",
+    "        result = func(*args, **kwargs)\n",
+    "        elapsed = time.perf_counter() - t0\n",
+    "        name = func.__name__\n",
+    "        arg_lst = [repr(arg) for arg in args]\n",
+    "        arg_lst.extend(f'{k}={v!r}' for k, v in kwargs.items())\n",
+    "        arg_str = ', '.join(arg_lst)\n",
+    "        print(f'[{elapsed:0.8f}s] {name}({arg_str}) -> {result!r}')\n",
+    "        return result\n",
+    "    return clocked"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "id": "8f8ddf80",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "@clock\n",
+    "def factorial(n):\n",
+    "    return 1 if n < 2 else n*factorial(n-1)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "id": "a26d70e5",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "[0.00000045s] factorial(1) -> 1\n",
+      "[0.00009076s] factorial(2) -> 2\n",
+      "[0.00011086s] factorial(3) -> 6\n",
+      "[0.00012257s] factorial(4) -> 24\n",
+      "[0.00013247s] factorial(5) -> 120\n",
+      "[0.00014292s] factorial(6) -> 720\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "720"
+      ]
+     },
+     "execution_count": 10,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "factorial(6)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "id": "54570916",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "@functools.cache\n",
+    "@clock\n",
+    "def fibonacci(n):\n",
+    "    if n < 2:\n",
+    "        return n\n",
+    "    return fibonacci(n - 2) + fibonacci(n - 1)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "id": "82312c5c",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "[0.00000069s] fibonacci(0) -> 0\n",
+      "[0.00000118s] fibonacci(1) -> 1\n",
+      "[0.00027445s] fibonacci(2) -> 1\n",
+      "[0.00000146s] fibonacci(3) -> 2\n",
+      "[0.00032200s] fibonacci(4) -> 3\n",
+      "[0.00000073s] fibonacci(5) -> 5\n",
+      "[0.00036564s] fibonacci(6) -> 8\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "8"
+      ]
+     },
+     "execution_count": 12,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "fibonacci(6)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "id": "c55780d1",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import html\n",
+    "\n",
+    "def htmlize(obj):\n",
+    "    content = html.escape(repr(obj))\n",
+    "    return f'<pre>{content}</pre>'"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "b3e8f075",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "base",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.13.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}
diff --git a/11-pythonic-obj/11-pythonic-obj-my.ipynb b/11-pythonic-obj/11-pythonic-obj-my.ipynb
new file mode 100644
index 0000000..2928417
--- /dev/null
+++ b/11-pythonic-obj/11-pythonic-obj-my.ipynb
@@ -0,0 +1,242 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "38d4dac9",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from array import array\n",
+    "import math"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "7d937f65",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Vector2d:\n",
+    "    typecode = 'd'\n",
+    "\n",
+    "    def __init__(self, x, y):\n",
+    "        self.__x = float(x)\n",
+    "        self.__y = float(y)\n",
+    "    \n",
+    "    @property\n",
+    "    def x(self):\n",
+    "        return self.__x\n",
+    "    \n",
+    "    @property\n",
+    "    def y(self):\n",
+    "        return self.__y\n",
+    "    \n",
+    "    def __iter__(self):\n",
+    "        return (i for i in (self.x, self.y))\n",
+    "    \n",
+    "    def __hash__(self):\n",
+    "        return hash((self.x, self.y))\n",
+    "    \n",
+    "    def __repr__(self):\n",
+    "        class_name = type(self).__name__\n",
+    "        return f'{class_name}({self.x!r}, {self.y!r})'\n",
+    "    \n",
+    "    def __str__(self):\n",
+    "        return str(tuple(self))\n",
+    "\n",
+    "    def __bytes__(self):\n",
+    "        return (bytes([ord(self.typecode)]) + bytes(array(self.typecode, self)))\n",
+    "    \n",
+    "    def __eq__(self, other):\n",
+    "        return tuple(self) == tuple(other)\n",
+    "    \n",
+    "    def __abs__(self):\n",
+    "        return math.hypot(self.x, self.y)\n",
+    "    \n",
+    "    def __bool__(self):\n",
+    "        return self.x or self.y\n",
+    "\n",
+    "    def __format__(self, fmt_spec=''):\n",
+    "        if fmt_spec.endswith('p'):\n",
+    "            fmt_spec = fmt_spec[:-1]\n",
+    "            coords = (abs(self), self.angle())\n",
+    "            outer_fmt = '<{}, {}>'\n",
+    "        else:\n",
+    "            coords = self\n",
+    "            outer_fmt = '({}, {})'\n",
+    "        components = (format(c, fmt_spec) for c in coords)\n",
+    "        return outer_fmt.format(*components)\n",
+    "\n",
+    "    def angle(self):\n",
+    "        return math.atan2(self.y, self.x)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "05ed942e",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'<1.4142135623730951, 0.7853981633974483>'"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "format(Vector2d(1, 1), 'p')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "b3caf933",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'<1.414e+00, 7.854e-01>'"
+      ]
+     },
+     "execution_count": 5,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "format(Vector2d(1, 1), '.3ep')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "3b32e574",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'<1.41421, 0.78540>'"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "format(Vector2d(1, 1), '0.5fp')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "1d2f1449",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Vector2d:\n",
+    "    typecode = 'd'\n",
+    "\n",
+    "    def __init__(self, x, y):\n",
+    "        self.__x = float(x)\n",
+    "        self.__y = float(y)\n",
+    "    \n",
+    "    @property\n",
+    "    def x(self):\n",
+    "        return self.__x\n",
+    "    \n",
+    "    @property\n",
+    "    def y(self):\n",
+    "        return self.__y\n",
+    "    \n",
+    "    def __iter__(self):\n",
+    "        return (i for i in (self.x, self.y))\n",
+    "    \n",
+    "    def __hash__(self):\n",
+    "        return hash((self.x, self.y))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "39d69e03",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "(1079245023883434373, 1994163070182233067)"
+      ]
+     },
+     "execution_count": 8,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "v1 = Vector2d(3, 4)\n",
+    "v2 = Vector2d(3.1, 4.2)\n",
+    "hash(v1), hash(v2)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "67812dd2",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{<__main__.Vector2d at 0x7141942456d0>, <__main__.Vector2d at 0x714195379a90>}"
+      ]
+     },
+     "execution_count": 9,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "{v1, v2}"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "dade208e",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "base",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.13.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}
diff --git a/13-protocol-abc/13-protocol-abc.ipynb b/13-protocol-abc/13-protocol-abc.ipynb
new file mode 100644
index 0000000..dcc9ac1
--- /dev/null
+++ b/13-protocol-abc/13-protocol-abc.ipynb
@@ -0,0 +1,316 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "cb82bca5",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import collections\n",
+    "\n",
+    "Card = collections.namedtuple('Card', ['rank', 'suit'])\n",
+    "\n",
+    "class FrenckDeck:\n",
+    "    ranks = [str(n) for n in range(2, 11)] + list('JQKA')\n",
+    "    suits = 'spades diamonds clubs hearts'.split()\n",
+    "\n",
+    "    def __init__(self):\n",
+    "        self._cards = [Card(rank, suit) for suit in self.suits for rank in self.ranks]\n",
+    "\n",
+    "    def __len__(self):\n",
+    "        return len(self._cards)\n",
+    "    \n",
+    "    def __getitem__(self, position):\n",
+    "        return self._cards[position]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "fbf12600",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from random import shuffle"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "5d3c4052",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def set_card(deck, position, card):\n",
+    "    deck._cards[position] = card\n",
+    "\n",
+    "FrenckDeck.__setitem__ = set_card"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "be98d6af",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[Card(rank='2', suit='spades'),\n",
+       " Card(rank='3', suit='spades'),\n",
+       " Card(rank='4', suit='spades'),\n",
+       " Card(rank='5', suit='spades'),\n",
+       " Card(rank='6', suit='spades')]"
+      ]
+     },
+     "execution_count": 5,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "deck = FrenckDeck()\n",
+    "deck[:5]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "fc497234",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[Card(rank='10', suit='diamonds'),\n",
+       " Card(rank='7', suit='diamonds'),\n",
+       " Card(rank='7', suit='clubs'),\n",
+       " Card(rank='8', suit='diamonds'),\n",
+       " Card(rank='Q', suit='diamonds')]"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "shuffle(deck)\n",
+    "deck[:5]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "262cae4e",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from collections import abc"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "9291022d",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class FrenckDeck2(abc.MutableSequence):\n",
+    "    ranks = [str(n) for n in range(2, 11)] + list('JQKA')\n",
+    "    suits = 'spades diamonds clubs hearts'.split()\n",
+    "\n",
+    "    def __init__(self):\n",
+    "        self._cards = [Card(rank, suit) for suit in self.suits for rank in self.ranks]\n",
+    "    \n",
+    "    def __len__(self):\n",
+    "        return len(self._cards)\n",
+    "    \n",
+    "    def __getitem__(self, index):\n",
+    "        return self._cards[index]\n",
+    "    \n",
+    "    def __setitem__(self, index, value):\n",
+    "        self._cards[index] = value\n",
+    "\n",
+    "    def __delitem__(self, index):\n",
+    "        del self._cards[index]\n",
+    "    \n",
+    "    def insert(self, index, value):\n",
+    "        self._cards.insert(index, value)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "993bf882",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "deck2 = FrenckDeck2()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "16572c41",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "Card(rank='A', suit='hearts')"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "deck2.pop()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "8f5aca7a",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "deck2.append(deck2.pop())"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "c1183e4b",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import abc\n",
+    "import random"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "9397e166",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Tombola(abc.ABC):\n",
+    "    @abc.abstractmethod\n",
+    "    def load(self, iterable):\n",
+    "        \"\"\"Add items from an iterable.\"\"\"\n",
+    "\n",
+    "    @abc.abstractmethod\n",
+    "    def pick(self):\n",
+    "        \"\"\"Remove item at random, returning it.\n",
+    "        \n",
+    "        This method should raise `LookupError` when then instance is empty.\n",
+    "        \"\"\"\n",
+    "    \n",
+    "    def loaded(self):\n",
+    "        \"\"\"Return `True` if there's at least 1 item, `False` otherwise.\"\"\"\n",
+    "        return bool(self.inspect())\n",
+    "    \n",
+    "    def inspect(self):\n",
+    "        \"\"\"Return a sorted tuple with the items currently inside.\"\"\"\n",
+    "        items = []\n",
+    "        while True:\n",
+    "            try:\n",
+    "                items.append(self.pick())\n",
+    "            except LookupError:\n",
+    "                break\n",
+    "        \n",
+    "        self.load(items)\n",
+    "        return tuple(items)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "ca6e8c04",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class BingoCage(Tombola):\n",
+    "    def __init__(self, items):\n",
+    "        self._randomizer = random.SystemRandom()\n",
+    "        self._items = []\n",
+    "        self.load(items)\n",
+    "\n",
+    "    def load(self, items):\n",
+    "        self._items.extend(items)\n",
+    "        self._randomizer.shuffle(self._items)\n",
+    "    \n",
+    "    def pick(self):\n",
+    "        try:\n",
+    "            return self._items.pop()\n",
+    "        except IndexError:\n",
+    "            raise LookupError('pick from empty BingoCage')\n",
+    "        \n",
+    "    def __call__(self):\n",
+    "        self.pick()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "25bede84",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class LottoBlower(Tombola):\n",
+    "    def __init__(self, iterable):\n",
+    "        self._balls = list(iterable)\n",
+    "    \n",
+    "    def load(self, iterable):\n",
+    "        self._balls.extend(iterable)\n",
+    "    \n",
+    "    def pick(self):\n",
+    "        try:\n",
+    "            position = random.randrange(len(self._balls))\n",
+    "        except ValueError:\n",
+    "            raise LookupError('pick from empty LottoBlower')\n",
+    "        return self._balls.pop(position)\n",
+    "    \n",
+    "    def loaded(self):\n",
+    "        return bool(self._balls)\n",
+    "    \n",
+    "    def inspect(self):\n",
+    "        return tuple(self._balls)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "6fe4ce2f",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "base",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.13.2"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}