Display label on each marker point in 2D plot

I'm using Matplotlib to create a projection of the ensemble onto PC1 and PC2:

plt.figure(figsize=(5,4))
showProjection(ensemble, pca[:2])
plt.show ()

Can anyone suggest me on how to label each marker point. Each point represent solved X-ray structure of proteins. I want to check which 开发者_开发技巧point represent each protein. Is it possible to plot the string label besides each point?

You can annotate a specific point in the image using plt.text(x,y,str). However, it looks like that will belong inside the showProjection function. Is that something you wrote yourself, or imported from some package?