Contour with curved labels

import scipy
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.textpath import TextPath
from matplotlib.patches import PathPatch
from matplotlib.font_manager import FontProperties

def f(x, y):
    return (1 - x / 2 + x ** 5 + y ** 3) * np.exp(-(x ** 2) - y ** 2)

n = 100
x = np.linspace(-3, 3, n)
y = np.linspace(-3, 3, n)
X, Y = np.meshgrid(x, y)
Z = 0.5 * f(X, Y)


fig, ax = plt.subplots(num=1, clear=True)
levels = 10


CF = plt.contourf(Z, origin="lower", levels=levels)
CS = plt.contour(Z, origin="lower", levels=levels, colors="black", linewidths=0.5)

# As we must set inline=False so that LocatorForAnn works. The locator will
# inline the path instead.
ax.clabel(CS, CS.levels, inline=False)

from mpl_visual_context.misc import curved_contour_labels
from mpl_visual_context.patheffects import GCModify, FillOnly

curved_contour_labels(CS,
                      text_patheffects=[GCModify(alpha=0.5, linewidth=3,
                                                 foreground="w"),
                                        FillOnly()])

plt.show()