Q:

Pandas plotting with multiple index labels

I have a pandas DataFrame that looks something like this:
n=pd.DataFrame({1:[1,2,np.NAN,4],2:[5,6,5,8],'info':[5,6,8,7],'moreinfo':[1,2,5,8]}).set_index(['info','moreinfo'])

Which looks like this:
                       1    2
info    moreinfo        
5       1            1.0    5
6       2            2.0    6
8       5            NaN    5
7       8            4.0    8

How can I line plot this such that:  
The column labels are used as the  xlabels
The data is grouped and colored by index
The y-axis is the numerical data found within each column.
Below is an example of what I'm thinking the plot should look like:  

A:

Let's try:
ax = n.T.plot(marker='o')
ax.set_xticks(n.T.index.astype(int))

Output:

You might want to fill that NaN with zero.
ax = n.fillna(0).T.plot(marker='o')
ax.set_xticks(n.T.index.astype(int))

Output:

