Matplotlib pie/donut chart annotation text size

Question

For the code given below to create a donut chart from matplotlib official page( https://matplotlib.org/3.1.1/gallery/pie_and_polar_charts/pie_and_donut_labels.html )

recipe = ["225 g flour",
          "90 g sugar",
          "1 egg",
          "60 g butter",
          "100 ml milk",
          "1/2 package of yeast"]

data = [225, 90, 50, 60, 100, 5]

wedges, texts = ax.pie(data, wedgeprops=dict(width=0.5), startangle=-40)

bbox_props = dict(boxstyle="square,pad=0.3", fc="w", ec="k", lw=0.72)
kw = dict(arrowprops=dict(arrowstyle="-"),
          bbox=bbox_props, zorder=0, va="center")

for i, p in enumerate(wedges):
    ang = (p.theta2 - p.theta1)/2. + p.theta1
    y = np.sin(np.deg2rad(ang))
    x = np.cos(np.deg2rad(ang))
    horizontalalignment = {-1: "right", 1: "left"}[int(np.sign(x))]
    connectionstyle = "angle,angleA=0,angleB={}".format(ang)
    kw["arrowprops"].update({"connectionstyle": connectionstyle})
    ax.annotate(recipe[i], xy=(x, y), xytext=(1.35*np.sign(x), 1.4*y),
                horizontalalignment=horizontalalignment, **kw)

ax.set_title("Matplotlib bakery: A donut")

plt.show()

I understand that the line

ax.annotate(recipe[i],xy(x,y),xytext(1.35*np.sign(x),1.4*y),horizontalalignment=horizontalalignment, **kw)

defines tha annotation, however I am not able to understand how to control the size of the annotation text.

Answer 1

You're correct in identifying that line as defining the annotation. From the documentation for ax.annotate , we can see that extra keywords are passed to a matplotlib.Text object. This object accepts a fontsize kwarg, which can be one of {size in points, 'xx-small', 'x-small', 'small', 'medium', 'large', 'x-large', 'xx-large'} .

For example:

ax.annotate(recipe[i], xy=(x, y), xytext=(1.35*np.sign(x), 1.4*y),
            horizontalalignment=horizontalalignment,
            fontsize=8, **kw)

Output:

Or with larger text:

ax.annotate(recipe[i], xy=(x, y), xytext=(1.35*np.sign(x), 1.4*y),
            horizontalalignment=horizontalalignment,
            fontsize=16, **kw)

Output: