更改Python直方图的图例格式

Question

我在同一张图中标注了两个不同的直方图，如下图。但是，两个直方图的图例采用方框的格式。我尝试了各种方法将框更改为行，但都不起作用。我想知道如何实现这样的功能？

Answer 1

一种方法是手动明确指定图例句柄：

handle1 = matplotlib.lines.Line2D([], [], c='r')
handle2 = matplotlib.lines.Line2D([], [], c='b')
plt.legend(handles=[handle1, handle2])

当然，这取决于您如何设置所有内容，这可能如下所示：

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.lines import Line2D

# Generate some data that sort of looks like that in the question
np.random.seed(0)
x1 = np.random.normal(2, 1, 200)
x2 = np.random.exponential(1, 200)

# Plot the data as histograms that look like unfilled lineplots
fig = plt.figure()
ax = fig.add_subplot(111)
ax.hist(x1, label='target', histtype='step')
ax.hist(x2, label='2nd halo', histtype='step')

# Create new legend handles but use the colors from the existing ones
handles, labels = ax.get_legend_handles_labels()
new_handles = [Line2D([], [], c=h.get_edgecolor()) for h in handles]

plt.legend(handles=new_handles, labels=labels)
plt.show()