matplotlib - Python scatter plot with colors corresponding to strings

Question

I want to make a scatter plot with python matplotlib where the color of the dot should correspond with a particular string from a data file, so something like this:

data = np.genfromtxt('filename.txt', delimiter=',', dtype=None, names=['a', 'b', 'c'])
plt.scatter(data['a'], data['b'])

Whereby the first column of the file 'a' is a float, the second column 'b' is a float and the third column 'c' is a string. The string column contains 5 different words which I would like to plot as 5 different colors is the scatter plot. Any ideas? Thanks a lot!

Answer 1

Something along these lines should do the trick:

color_dict = { 'Allan':'red', 'Betty':'blue', 'Chris':'black', 'Diane':'green','Eugene':'purple' }

plt.scatter( data['a'], data['b'], color=[ color_dict[i] for i in data['c'] ] )