Matplotlib：使用不同的 colors 和不同的 alpha 并排绘制多个直方图

Question

I want to plot multiple data into a histogram, where each dataset has it's own color and alpha value. I tried this:

colors = ['red', 'green', 'blue']
alphas = [1.0, 0.7, 0.3]
plt.hist([data1, data2, data3], bins = 15, label=['Data 1', 'Data 2', 'Data 3'], color = colors, alpha = alphas)

However, I get the following error:

alpha must be numeric or None, not <class 'list'>

but I want different alpha values for each histogram. How can I achieve that?

I tried using zip as @BigBen suggested in the comments:

datas = [data1, data2, data3]
colors = ['red', 'green', 'blue']
alphas = [1.0, 0.7, 0.3]
labels = ['Data 1', 'Data 2', 'Data 3']
plt.savefig('images/bla.png')
for data, label, color, alpha in zip(datas, labels, colors, alphas):
    plt.hist(data, bins=10, label=label, color=color, alpha=alpha)

However, the result looks like this:

But I need something like this, but with different alpha values for different colors:

Answer 1

matplotlib.colors.to_rgba is the solution. With it, one can add alpha values to colors.

red = matplotlib.colors.to_rgba('red', alpha=1)
green = matplotlib.colors.to_rgba('green', alpha=0.7)
blue = matplotlib.colors.to_rgba('blue', alpha=0.3)
colors = [red, green, blue]

plt.hist([data1, data2, data3], bins = 15, label=['Data 1', 'Data 2', 'Data 3'], color = colors)