[Python] How to convert annotation in bold text?

This is a reproducible program displaying an annotated line:

import numpy as np
import matplotlib.pyplot as plt
plt.rcParams['text.usetex'] = True

fig, ax = plt.subplots(figsize=(6, 4))

point1 = [0, 1]
point2 = [np.sqrt(2), 0]
x_values = [point1[0], point2[0]]
y_values = [point1[1], point2[1]]

ax.plot(x_values, y_values, 'bo', linestyle="-")
ax.annotate( r"$y = -\,\frac{1}{\sqrt(2)}x + 1$", xy = (0.2, 0.7), rotation = -35, fontsize = 12)

plt.show()


Now looking for the best way to display the annotation in bold .

I tried to use \textbf:

ax.annotate( r"\textbf{$y = -\,\frac{1}{\sqrt(2)}x + 1$}", xy = (0.2, 0.7), rotation = -35, fontsize = 12)


but nothing changed. I guess a misuse of \textbf... What would be the proper use?

Continue reading...