Python matplotlib代码运行成功但周CPU使用率图表无法显示求助

核心问题排查与修复 #

1. 补充缺失的导入语句 #

你的代码中使用了plt（matplotlib.pyplot）和np（numpy）但未显式导入，这是导致图表无法正常渲染的核心原因。在代码最顶部添加以下导入：

import matplotlib.pyplot as plt
import numpy as np

2. 适配不同运行环境 #

• Python脚本环境：如果在本地脚本运行，若仍无法显示，可指定Matplotlib的显示后端（根据系统选择合适的后端，比如TkAgg、Qt5Agg）：

  plt.switch_backend('TkAgg')
  

  确保系统已安装对应后端的依赖（如Tkinter、PyQt5等）。
• Jupyter Notebook环境：添加魔法命令让图表内嵌显示：

  %matplotlib inline
  

  若需要交互式图表，改用：

  %matplotlib notebook
  

修复后的完整代码 #

import matplotlib.pyplot as plt
import numpy as np

cpu_usage = [
[2, 2, 4, 2, 4, 1, 1, 4, 4, 12, 22, 23,
 45, 9, 33, 56, 23, 40, 21, 6, 6, 2, 2, 3], # Monday
[1, 2, 3, 2, 3, 2, 3, 2, 7, 22, 45, 44,
 33, 9, 23, 19, 33, 56, 12, 2, 3, 1, 2, 2], # Tuesday
[2, 3, 1, 2, 4, 4, 2, 2, 1, 2, 5, 31,
 54, 7, 6, 34, 68, 34, 49, 6, 6, 2, 2, 3], # Wednesday
[1, 2, 3, 2, 4, 1, 2, 4, 1, 17, 24, 18,
 41, 3, 44, 42, 12, 36, 41, 2, 2, 4, 2, 4], # Thursday
[4, 1, 2, 2, 3, 2, 5, 1, 2, 12, 33, 27,
 43, 8, 38, 53, 29, 45, 39, 3, 1, 1, 3, 4], # Friday
[2, 3, 1, 2, 2, 5, 2, 8, 4, 2, 3,
 1, 5, 1, 2, 3, 2, 6, 1, 2, 2, 1, 4, 3], # Saturday
[1, 2, 3, 1, 1, 3, 4, 2, 3, 1, 2,
 2, 5, 3, 2, 1, 4, 2, 45, 26, 33, 2, 2, 1], # Sunday
]

labels=["Mon","Tue","Wed","Thu","Fri","Sat","Sun"]

for day in range(len(cpu_usage)):
  plt.plot(np.arange(24),cpu_usage[day],"--o",label=labels[day],linewidth=.4,markersize=4)

plt.xticks(np.arange(24))
plt.legend(loc="best")
plt.xlabel('hour')
plt.ylabel('cpu usage')
plt.show()

额外优化建议 #

• 调整linewidth（如改为1）和markersize（如改为5），让线条和标记更清晰
• 添加图表标题：plt.title('Weekly Hourly CPU Usage')
• 设置y轴范围，避免极值干扰整体观察：plt.ylim(0, 70)

内容的提问来源于stack exchange，提问作者Yuda Dian Febriansyah