The root issue here is that IDLE is using a different Python interpreter than your PyCharm virtual environment—so it doesn't have access to the pandas and xlsx-related libraries you installed in the venv. Here are three solid solutions to get your program running in IDLE:

1. Launch IDLE Directly From Your Virtual Environment #

This is the cleanest approach, since it makes IDLE use exactly the same Python setup as PyCharm:

• Open your system terminal (not PyCharm's terminal) and navigate to your project folder.
• Activate your virtual environment:
  • Windows: venv\Scripts\activate.bat
  • macOS/Linux: source venv/bin/activate
• Once the venv is active, run this command to start IDLE:

  python -m idlelib.idle
  

• The IDLE instance that opens will have full access to all libraries installed in your venv—just open main.py and run it like normal.

2. Install Pandas (and Dependencies) for IDLE's Python Interpreter #

If you prefer to keep using your system's default IDLE (Python 3.8), install the required libraries directly into that environment:

• Open IDLE, go to the Shell window, and run this to find the path of the Python interpreter IDLE is using:

  import sys
  print(sys.executable)
  

• Copy that path (e.g., C:\Python38\python.exe or /usr/bin/python3.8).
• Open a system terminal and run this command (replace [PATH_TO_PYTHON] with the path you copied):

  [PATH_TO_PYTHON] -m pip install pandas openpyxl
  

  (Note: openpyxl is a common dependency for reading/writing Excel files with pandas—include it if your xlsx handling relies on it.)

3. Temporarily Add Your Venv's Libraries to IDLE's Path (Quick Fix) #

If you need a one-off solution without modifying environments, you can manually add your venv's site-packages folder to IDLE's Python path:

• First, find the site-packages folder in your venv:
  • Windows: your-project-folder\venv\Lib\site-packages
  • macOS/Linux: your-project-folder/venv/lib/python3.8/site-packages (make sure the Python version matches IDLE's 3.8)
• In IDLE's Shell, run this before importing pandas (replace [PATH_TO_SITE_PACKAGES] with the actual path):

  import sys
  sys.path.append("[PATH_TO_SITE_PACKAGES]")
  

• Now you can open and run main.py successfully—just remember this fix resets every time you close IDLE.

Pro Tip #

Double-check that your PyCharm venv is using Python 3.8 (matching IDLE's version) to avoid any unexpected compatibility issues. You can confirm this in PyCharm's project settings under Project Interpreter.

内容的提问来源于stack exchange，提问作者thatdevop