@ImportanceOfBeingErnest的答案很好，如果您只想更改图例框中的线宽。但我认为这有点复杂，因为在更改图例线宽之前必须复制句柄。此外，它不能更改图例标签字体大小。以下两种方法不仅可以更简洁地改变线宽，还可以改变图例标签文本的字体大小。
方法1import numpy as np
import matplotlib.pyplot as plt
# make some data
x = np.linspace(0, 2*np.pi)
y1 = np.sin(x)
y2 = np.cos(x)
# plot sin(x) and cos(x)
fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot(x, y1, c=’b’, label=’y1′)
ax.plot(x, y2, c=’r’, label=’y2′)
leg = plt.legend()
# get the individual lines inside legend and set line width
for line in leg.get_lines():
line.set_linewidth(4)
# get label texts inside legend and set font size
for text in leg.get_texts():
text.set_fontsize(‘x-large’)
plt.savefig(‘leg_example’)
plt.sh