Session Ready
Exercise

Visualizing connectivity

Here, you're going to visualize how the connectivity of the top connected nodes changes over time. The list of top connected values, top_connected, from the previous exercise has been loaded.

Remember the defaultdict you used in Chapter 1? You'll use another defaultdict in this exercise! As Eric mentioned in the video, a defaultdict is preferred here as a regular Python dictionary would throw a KeyError if you try to get an item with a key that is not currently in the dictionary.

This exercise will make use of nested for loops. That is, you'll use one for loop inside another.

Instructions
100 XP
  • Initialize a defaultdict of empty lists called connectivity.
  • Iterate over top_connected using a for loop, and in the body of this outer for loop, once again iterate over Gs. Inside this nested loop:
    • The keys of connectivity should be the nodes n in top_connected, and the values should be the list of connectivity scores. Therefore, you have to append len(g.neighbors(n)) to connectivity[n].
  • Iterate over connectivity using .items() and plot the connectivity of each node by passing in conn to plt.plot().