plt.legend(loc=0, numpoints=1)
leg = plt.gca().get_legend() #或leg=ax.get_legend()
ltext = leg.get_texts()
plt.setp(ltext, fontsize=12,fontweight='bold') 

legend = ax.legend((rectsTest1, rectsTest2, rectsTest3), ('test1', 'test2', 'test3')) 
legend = ax.legend(loc='upper center', shadow=True, fontsize='x-large')
legend.get_frame().set_facecolor('red') #設(shè)置圖例legend背景為紅色
frame = legend.get_frame() 
frame.set_alpha(1) 
frame.set_facecolor('none') #設(shè)置圖例legend背景透明 

ax1.legend_.remove() ##移除子圖ax1中的圖例
ax2.legend_.remove() ##移除子圖ax2中的圖例
ax3.legend_.remove() ##移除子圖ax3中的圖例

#主要是bbox_to_anchor的使用
box = ax1.get_position()
ax1.set_position([box.x0, box.y0, box.width , box.height* 0.8])
ax1.legend(loc='center', bbox_to_anchor=(0.5, 1.2),ncol=3)

import matplotlib.pyplot as plt
import numpy as np
x = np.random.uniform(-1, 1, 4)
y = np.random.uniform(-1, 1, 4)
p1, = plt.plot([1,2,3])
p2, = plt.plot([3,2,1])
l1 = plt.legend([p2, p1], ["line 2", "line 1"], loc='upper left')
 
p3 = plt.scatter(x[0:2], y[0:2], marker = 'D', color='r')
p4 = plt.scatter(x[2:], y[2:], marker = 'D', color='g')
# This removes l1 from the axes.
plt.legend([p3, p4], ['label', 'label1'], loc='lower right', scatterpoints=1)
# Add l1 as a separate artist to the axes
plt.gca().add_artist(l1)

import matplotlib.pyplot as plt
line1, = plt.plot([1,2,3], label="Line 1", linestyle='--')
line2, = plt.plot([3,2,1], label="Line 2", linewidth=4)
# 為第一個(gè)線條創(chuàng)建圖例
first_legend = plt.legend(handles=[line1], loc=1)
# 手動(dòng)將圖例添加到當(dāng)前軸域
ax = plt.gca().add_artist(first_legend)
# 為第二個(gè)線條創(chuàng)建另一個(gè)圖例
plt.legend(handles=[line2], loc=4)
plt.show()