显示图例
import matplotlib.gridspec as gridspec
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.ticker import MultipleLocator, FormatStrFormatter
# 生成X数据
x_data = np.linspace(-2,2,50)
# Y数据
y1 = np.sin(10*x_data)*np.exp(-x_data) - 0.5
y2 = np.square(x_data)
l1, = plt.plot(x_data, y1, c='r', lw=2, ls = '-.')
l2, = plt.plot(x_data, y2, c='g')
plt.xlabel('X')
plt.ylabel('Y')
plt.legend(handles=[l1, l2], labels=['$sin(x)*exp(x)$', '$x^2$'])
plt.savefig('d:/f.png')
plt.show()