我推荐使用answer suggested in the comments，但另一种方法与第一种方法类似（尽管图例标记的位置与关联线的位置不匹配），该方法是：

import numpy as np

import matplotlib.pyplot as plt

fig, ax = plt.subplots()

n=10
x = np.linspace(0, 1, n)
labels = [str(i) for i in range(len(x))]

for i in range(n):
    y = np.linspace(x[i], x[i], n)
    ax.plot(x, y, label=labels[i])

h, _ = ax.get_legend_handles_labels()

# sort the legend handles/labels so they are in the same order as the data
hls = sorted(zip(x, h, labels), reverse=True)

ax.legend(
    [ha[1] for ha in hls],  # get handles
    [la[2] for la in hls],  # get labels
    bbox_to_anchor=(1.04, 0, 0.1, 1),  # set box outside of axes
    loc="lower left",
    labelspacing=1.6,  # add space between labels
)

leg = ax.get_legend()

# expand the border of the legend
fontsize = fig.canvas.get_renderer().points_to_pixels(leg._fontsize)
pad = 2 * (leg.borderaxespad + leg.borderpad) * fontsize
leg._legend_box.set_height(leg.get_bbox_to_anchor().height - pad)

这在很大程度上依赖于here和here的答案。