PyCharm中Matplotlib未调用show()仍启动绘图界面及卡顿问题求助

Hey there, let's break down how to fix that annoying background plot window and speed up your PyCharm setup overall:

Stop Background Plot Windows from Popping Up #

The issue here is that Matplotlib is using an interactive backend by default in your PyCharm environment, which creates a GUI context even when you don’t call plt.show(). Here’s the simplest, most reliable fix:

Add this at the very top of your script to switch to a non-interactive backend that renders directly to file without any GUI windows:

import matplotlib
# Use a non-interactive backend to avoid hidden GUI windows
matplotlib.use('Agg')
import matplotlib.pyplot as plt

# Rest of your plotting code stays exactly the same
fig, ax = plt.subplots(1, 1, figsize=(12,9))
ax.plot(years, data, color=c[0])
# ... [your existing figure setup]
fig.savefig('rate.png', dpi=144, bbox_inches='tight')
plt.close(fig)

This will completely prevent any background plot windows from opening. If you ever need to go back to interactive plotting (to view plots live), just comment out the matplotlib.use('Agg') line.

For your older PyCharm version (2017.3), this backend switch is the most dependable solution—newer versions have more refined plot tool window controls, but this works across all Matplotlib and PyCharm releases.

Speed Up PyCharm and Script Execution #

Your PyCharm version is quite dated, so these tips will make a noticeable difference in performance:

• Upgrade PyCharm: JetBrains has made massive performance improvements since 2017. Newer releases (2023/2024) have faster script execution, smoother Matplotlib integration, and reduced background overhead. This is the single most impactful change you can make.
• Boost Heap Memory: Older PyCharm installs default to low memory limits. To increase it:
  1. Go to Help > Edit Custom VM Options
  2. Find the line starting with -Xmx (e.g., -Xmx1024m)
  3. Change it to -Xmx2048m (if you have 8GB RAM) or -Xmx3072m (16GB+ RAM)
  4. Restart PyCharm
• Disable Unused Plugins: Navigate to File > Settings > Plugins and turn off any plugins you don’t use (like cloud integrations, database tools, or version control plugins you aren’t actively working with). Each plugin runs background processes that consume resources.
• Optimize Matplotlib for Interactive Use (when needed): If you do need interactive plots sometimes, switch to a faster backend like Qt5Agg instead of the default TkAgg. Add this line at the start of your script:

  matplotlib.use('Qt5Agg')
  

  Qt-based backends are smoother and faster than TkAgg in PyCharm.
• Use a Newer Python Version: If you’re on Python 3.6 or earlier, upgrading to Python 3.8+ will improve script speed, especially for data processing loops that often pair with Matplotlib plots.
• Tweak Background Inspections: Go to File > Settings > Editor > Inspections and disable any code inspections that aren’t critical for your workflow. This reduces the background processing PyCharm does while you run scripts.

Content of the question originates from Stack Exchange, asked by Yorian