post-tutorial push

Former-commit-id: 2407290

1-introduction.ipynb

@@ -4,7 +4,7 @@
    "cell_type": "markdown",
    "metadata": {
     "slideshow": {
-     "slide_type": "slide"
+     "slide_type": "skip"
     }
    },
    "source": [
@@ -131,17 +131,17 @@
     }
    },
    "source": [
-    "# Examples of Networks\n",
-    "\n",
+    "# Examples of Networks"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
     "1. Facebook's network: Individuals are nodes, edges are drawn between individuals who are FB friends with one another. **undirected network**.\n",
     "2. Air traffic network: Airports are nodes, flights between airports are the edges. **directed network**.\n",
     "\n",
-    "Can you think of any others?\n",
-    "\n",
-    "The key questions here are as follows. How do we...:\n",
-    "\n",
-    "1. model a problem as a network?\n",
-    "2. extract useful information from a network?"
+    "Can you think of any others?"
    ]
   },
   {
@@ -178,6 +178,21 @@
     "- Think through statistical problems in network analysis."
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "slideshow": {
+     "slide_type": "slide"
+    }
+   },
+   "source": [
+    "# Tutorial Format\n",
+    "\n",
+    "- Student notebooks for coding exercises.\n",
+    "- Instructor versions for reference.\n",
+    "- Feel free to skip ahead of myself if I'm too slow for you."
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {

3-hubs-and-paths-student.ipynb

@@ -437,12 +437,6 @@
     "def path_exists(node1, node2, G):\n",
     "    \"\"\"\n",
     "    This function checks whether a path exists between two nodes (node1, node2) in graph G.\n",
-    "    \n",
-    "    Special thanks to @ghirlekar for suggesting that we keep track of the \"visited nodes\" to\n",
-    "    prevent infinite loops from happening. This also removes the need to remove nodes from\n",
-    "    queue.\n",
-    "    \n",
-    "    Reference: https://github.com/ericmjl/Network-Analysis-Made-Simple/issues/3\n",
     "    \"\"\"\n",
     "    visited_nodes = set()\n",
     "    queue = [node1]\n",
@@ -456,9 +450,9 @@
     "        else:\n",
     "            _________.add(______)\n",
     "            _______.extend(________)\n",
-    "        if len(queue) == 0:\n",
-    "            print('Path does not exist between nodes {0} and {1}'.format(node1, node2))\n",
-    "            return False\n",
+    "\n",
+    "    print('Path does not exist between nodes {0} and {1}'.format(node1, node2))\n",
+    "    return False\n",
     "    "
    ]
   },
@@ -571,7 +565,7 @@
    "source": [
     "### Exercise\n",
     "\n",
-    "Write a function that extracts the edges in the shortest path between two nodes and puts them into a new graph, and draws it to the screen. It should also return an error if there is no path between the two nodes. (10 min.)\n",
+    "Write a function that extracts the edges in the shortest path between two nodes and puts them into a new graph, and draws it to the screen. It should also return an error if there is no path between the two nodes. (5 min.)\n",
     "\n",
     "Hint: You may want to use `G.subgraph(iterable_of_nodes)` to extract just the nodes and edges of interest from the graph `G`. You might want to use the following lines of code somewhere:\n",
     "\n",