matplotlib导入错误：无法导入_string_to_bool 环境排查求助

Hey there, I feel your pain—nothing's more annoying than code that worked perfectly weeks ago suddenly throwing import errors, especially when you're sure your Python setup hasn't changed. Let's walk through practical steps to fix this:

1. Verify Matplotlib Version Compatibility with Python 2.7 #

Python 2.7 is no longer supported, and newer Matplotlib versions dropped support for it entirely. The last Matplotlib release compatible with Python 2.7 is 2.2.5.

• Check your current Matplotlib version with:

  pip show matplotlib
  

• If you have a newer version, downgrade to 2.2.5 using:

  pip install matplotlib==2.2.5
  

2. Check for Corrupted Matplotlib Installation #

Sometimes files in your site-packages can get corrupted accidentally. A clean reinstall often fixes this:

• Uninstall the current Matplotlib:

  pip uninstall matplotlib -y
  

• Reinstall the compatible version:

  pip install matplotlib==2.2.5
  

3. Validate the Six Module (Even Though Pip Says It's Installed) #

While pip confirms six is present, there might be version mismatches or path issues:

• First, check where six is being loaded from. Open a Python 2.7 shell and run:

  import six
  print(six.__file__)
  

  Make sure the path points to C:\Python27\lib\site-packages\six.py (or .pyc). If it's pointing elsewhere, you might have another Python environment interfering.
• Matplotlib 2.2.x works best with six version 1.15.0. Upgrade/downgrade six to this version:

  pip install six==1.15.0
  

4. Double-Check Your Python Environment #

It's easy to accidentally switch environments without realizing it:

• Confirm you're using the correct Python 2.7 executable:

  python --version
  where python
  

  Ensure the output shows Python 2.7.x and the path is C:\Python27\python.exe.
• Check your PYTHONPATH environment variable (in Command Prompt: echo %PYTHONPATH%). If it includes other Python site-packages directories, those might be overriding your Matplotlib installation.

5. Inspect the Matplotlib Cbook Module Directly #

The error says _string_to_bool is missing from matplotlib.cbook. Let's verify this:

• Navigate to C:\Python27\lib\site-packages\matplotlib\ and open cbook.py in a text editor.
• Search for the string _string_to_bool. If it's not present, your Matplotlib installation is definitely corrupted, and a reinstall (step 2) will fix it.

内容的提问来源于stack exchange，提问作者Charles