Matplotlib - Chinese characters are not shown when saving figure as 'eps' files

Question

The problem is described as the title.

For example:

import matplotlib as mpl
mpl.use('Agg')
import matplotlib.pyplot as plt
mpl.rcParams['font.sans-serif'] = ['SimHei']

plt.figure()
plt.title('哈哈')
plt.savefig('try.png')
plt.savefig('try.eps')

Then, the results:

try.png :

try.eps :

The saving method works fine with 'png', 'jpg', but it cannot render chinese characters in 'eps'. Besides, you can find the number's font in the eps plot also looks weird.