Notebooks: replace per-notebook bootstrap cell with a shared %run bootstrap.ipynb

Per Peter Norvig's review note on #1340: instead of several lines in each
notebook's bootstrap cell, use one '%run bootstrap.ipynb'.

- Added notebooks/bootstrap.ipynb: walks up to the repo root (the dir containing
  the aima package) and puts it on sys.path -- no chdir, so it is idempotent and
  works whether run from notebooks/ or notebooks/chapterNN/.
- Replaced the bootstrap cell in all 36 top-level notebooks with '%run bootstrap.ipynb'.
- Dropping the chdir means cwd-relative resource paths had to be anchored to the
  repo root via __file__ (makes the package cwd-independent, also good for
  'pip install -e .'):
  - notebook_utils: load_MNIST path + images/queen_s.png
  - ipyviews: js/continuousworld.js, js/gridworld.js (opened at import time)
  - perception: images/stapler1-test.png
  - improving_sat_algorithms.ipynb: open('aima-data/zebra.cnf') -> open_data('zebra.cnf')

Verified: full suite 393 passed; agents/csp/probability/learning_apps/search run
clean with the shared bootstrap; modules import correctly from an unrelated cwd.

Author: dmeoli

aima/ipyviews.py

@@ -1,11 +1,16 @@
 from IPython.display import HTML, display, clear_output
 from collections import defaultdict
 from aima.agents import PolygonObstacle
+import os
 import time
 import json
 import copy
 import __main__
 
+# repo root (the directory containing the `aima` package), so the bundled js/
+# files load regardless of the current working directory
+_AIMA_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
 # ______________________________________________________________________________
 # Continuous environment
 
@@ -21,7 +26,7 @@
 </script>
 '''  # noqa
 
-with open('js/continuousworld.js', 'r') as js_file:
+with open(os.path.join(_AIMA_ROOT, 'js/continuousworld.js'), 'r') as js_file:
     _JS_CONTINUOUS_WORLD = js_file.read()
 
 
@@ -88,7 +93,7 @@ def show(self):
 </script>
 '''
 
-with open('js/gridworld.js', 'r') as js_file:
+with open(os.path.join(_AIMA_ROOT, 'js/gridworld.js'), 'r') as js_file:
     _JS_GRID_WORLD = js_file.read()
 
 

aima/notebook_utils.py

@@ -1,3 +1,4 @@
+import os
 import time
 from collections import defaultdict
 from inspect import getsource
@@ -16,6 +17,10 @@
 from aima.logic import parse_definite_clause, standardize_variables, unify_mm, subst
 from aima.search import GraphProblem, romania_map
 
+# repo root (the directory containing the `aima` package), so cwd-relative
+# data/image paths resolve regardless of where a notebook is launched from
+_AIMA_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
 
 # ______________________________________________________________________________
 # Magic Words
@@ -109,6 +114,9 @@ def load_MNIST(path="aima-data/MNIST/Digits", fashion=False):
     if fashion:
         path = "aima-data/MNIST/Fashion"
 
+    if not os.path.isabs(path):
+        path = os.path.join(_AIMA_ROOT, path)
+
     plt.rcParams.update(plt.rcParamsDefault)
     plt.rcParams['figure.figsize'] = (10.0, 8.0)
     plt.rcParams['image.interpolation'] = 'nearest'
@@ -1122,7 +1130,7 @@ def plot_NQueens(solution):
     """
     n = len(solution)
     board = np.array([2 * int((i + j) % 2) for j in range(n) for i in range(n)]).reshape((n, n))
-    im = Image.open('images/queen_s.png')
+    im = Image.open(os.path.join(_AIMA_ROOT, 'images/queen_s.png'))
     height = im.size[1]
     im = np.array(im).astype(float) / 255
     fig = plt.figure(figsize=(7, 7))

aima/perception.py

@@ -1,5 +1,7 @@
 """Perception (Chapter 24)"""
 
+import os
+
 import cv2
 import keras
 import matplotlib.pyplot as plt
@@ -11,6 +13,10 @@
 
 from aima.utils import gaussian_kernel_2D
 
+# repo root (the directory containing the `aima` package), so the bundled sample
+# images resolve regardless of the current working directory
+_AIMA_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
 
 # ____________________________________________________
 # 24.3 Early Image Processing Operators
@@ -366,7 +372,7 @@ def selective_search(image):
     :return list of bounding boxes, each element is in form of [x_min, y_min, x_max, y_max]
     """
     if not image:
-        im = cv2.imread("./images/stapler1-test.png")
+        im = cv2.imread(os.path.join(_AIMA_ROOT, "images/stapler1-test.png"))
     elif isinstance(image, str):
         im = cv2.imread(image)
     else:

notebooks/agents.ipynb

@@ -6,13 +6,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# notebooks live under notebooks/; run from the repo root so that\n",
-    "# `from aima import ...` and the cwd-relative aima-data/ and images/ paths resolve.\n",
-    "import os, sys\n",
-    "if os.path.basename(os.getcwd()) == 'notebooks':\n",
-    "    os.chdir('..')\n",
-    "if os.getcwd() not in sys.path:\n",
-    "    sys.path.insert(0, os.getcwd())"
+    "%run bootstrap.ipynb"
    ]
   },
   {

notebooks/arc_consistency_heuristics.ipynb

@@ -6,13 +6,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# notebooks live under notebooks/; run from the repo root so that\n",
-    "# `from aima import ...` and the cwd-relative aima-data/ and images/ paths resolve.\n",
-    "import os, sys\n",
-    "if os.path.basename(os.getcwd()) == 'notebooks':\n",
-    "    os.chdir('..')\n",
-    "if os.getcwd() not in sys.path:\n",
-    "    sys.path.insert(0, os.getcwd())"
+    "%run bootstrap.ipynb"
    ]
   },
   {

notebooks/bootstrap.ipynb

@@ -0,0 +1,40 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Bootstrap\n",
+    "\n",
+    "Shared setup for the notebooks: put the repository root (the directory containing the `aima` package) on `sys.path` so `from aima import ...` works regardless of where the notebook is launched. Each notebook runs this with a single `%run bootstrap.ipynb` cell."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import os, sys\n",
+    "# walk up from the current directory to the repo root (the one holding `aima/`)\n",
+    "_root = os.path.abspath(os.getcwd())\n",
+    "while _root != os.path.dirname(_root) and not os.path.isdir(os.path.join(_root, 'aima')):\n",
+    "    _root = os.path.dirname(_root)\n",
+    "if _root not in sys.path:\n",
+    "    sys.path.insert(0, _root)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "name": "python"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

notebooks/classical_planning_approaches.ipynb

@@ -6,13 +6,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# notebooks live under notebooks/; run from the repo root so that\n",
-    "# `from aima import ...` and the cwd-relative aima-data/ and images/ paths resolve.\n",
-    "import os, sys\n",
-    "if os.path.basename(os.getcwd()) == 'notebooks':\n",
-    "    os.chdir('..')\n",
-    "if os.getcwd() not in sys.path:\n",
-    "    sys.path.insert(0, os.getcwd())"
+    "%run bootstrap.ipynb"
    ]
   },
   {

notebooks/csp.ipynb

@@ -6,13 +6,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# notebooks live under notebooks/; run from the repo root so that\n",
-    "# `from aima import ...` and the cwd-relative aima-data/ and images/ paths resolve.\n",
-    "import os, sys\n",
-    "if os.path.basename(os.getcwd()) == 'notebooks':\n",
-    "    os.chdir('..')\n",
-    "if os.getcwd() not in sys.path:\n",
-    "    sys.path.insert(0, os.getcwd())"
+    "%run bootstrap.ipynb"
    ]
   },
   {

notebooks/dynamic_decision_network.ipynb

@@ -6,13 +6,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# notebooks live under notebooks/; run from the repo root so that\n",
-    "# `from aima import ...` and the cwd-relative aima-data/ and images/ paths resolve.\n",
-    "import os, sys\n",
-    "if os.path.basename(os.getcwd()) == 'notebooks':\n",
-    "    os.chdir('..')\n",
-    "if os.getcwd() not in sys.path:\n",
-    "    sys.path.insert(0, os.getcwd())"
+    "%run bootstrap.ipynb"
    ]
   },
   {

notebooks/expectation_maximization.ipynb

@@ -6,13 +6,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# notebooks live under notebooks/; run from the repo root so that\n",
-    "# `from aima import ...` and the cwd-relative aima-data/ and images/ paths resolve.\n",
-    "import os, sys\n",
-    "if os.path.basename(os.getcwd()) == 'notebooks':\n",
-    "    os.chdir('..')\n",
-    "if os.getcwd() not in sys.path:\n",
-    "    sys.path.insert(0, os.getcwd())"
+    "%run bootstrap.ipynb"
    ]
   },
   {