Add import os

classification.ipynb

@@ -21,6 +21,8 @@
     "import numpy.random as rnd\n",
     "rnd.seed(42) # to make this notebook's output stable across runs\n",
     "\n",
+    "import os\n",
+    "\n",
     "%matplotlib inline\n",
     "import matplotlib\n",
     "import matplotlib.pyplot as plt\n",

end_to_end_project.ipynb

@@ -33,6 +33,8 @@
    "source": [
     "from __future__ import division, print_function, unicode_literals\n",
     "\n",
+    "import os\n",
+    "\n",
     "%matplotlib inline\n",
     "import matplotlib.pyplot as plt\n",
     "plt.rcParams['axes.labelsize'] = 14\n",

fundamentals.ipynb

@@ -20,6 +20,8 @@
    "source": [
     "from __future__ import division, print_function, unicode_literals\n",
     "\n",
+    "import os\n",
+    "\n",
     "%matplotlib inline\n",
     "import matplotlib.pyplot as plt\n",
     "\n",

training_linear_models.ipynb

@@ -17,13 +17,12 @@
    "source": [
     "from __future__ import division, print_function, unicode_literals\n",
     "\n",
+    "import os\n",
+    "\n",
     "import numpy as np\n",
     "import numpy.random as rnd\n",
     "rnd.seed(42) # to make this notebook's output stable across runs\n",
     "\n",
-    "from sklearn.linear_model import LinearRegression\n",
-    "LinearRegression().fit([[5]], [3])\n",
-    "\n",
     "%matplotlib inline\n",
     "import matplotlib\n",
     "import matplotlib.pyplot as plt\n",