How to Display Chinese Characters in Matplotlib Plots (Step‑by‑Step)

Matplotlib does not display Chinese characters by default, resulting in small squares instead of the intended text. To correctly show Chinese in plots, you can (1) specify a font directly in the program, (2) modify the rcParams dictionary at the start of the script, or (3) edit the Matplotlib configuration file.

<code>from matplotlib.font_manager import FontProperties
import matplotlib.pyplot as plt
import numpy as np
font = FontProperties(fname="C:/Windows/Fonts/STXINGKA.TTF")

x = np.linspace(0, 10, 100)
y = x**2 - 2 * x
plt.plot(x, y, label='$y=x^2-2x$')
plt.xlabel('横坐标', fontproperties=font)
plt.ylabel('纵坐标', fontproperties=font)
plt.title('标题', fontproperties=font)
plt.legend()
</code>

In the code above, the font = FontProperties(fname="C:/Windows/Fonts/STXINGKA.TTF") line sets the font to a Chinese typeface located in the system’s font directory; STXINGKA refers to the "华文行楷" font. For Windows systems, a simpler alternative is to set the font family at the beginning of the script, e.g., plt.rcParams['font.family'] = ['SimHei'] , which uses the SimHei (Microsoft YaHei) font.

Reference: 朱顺泉, 《经济金融数据分析及其Python应用》