Matplotlib - plotting transparent and overlapping time series

Question

I've been searching for a solution to generate a figure of overlapping time series, i.e., http://grollchristian.files.wordpress.com/2013/04/wpid-224.png?w=604

However, the only script I found online is done in R (above pic) or Matlab. What is my option under matplotlib?

Answer 1

In matplotlib it is controlled by alpha argument.

You can do: plt.plot(x_data, y_data, color='black', alpha=0.4)