Fix Colab import error and suppress hdbscan SyntaxWarning

[jeremymanning]

Summary

• Fix ValueError/UnboundLocalError when importing hypertools in Google Colab
• Suppress SyntaxWarning from hdbscan's unescaped LaTeX docstrings in Python 3.12+

Problem

When importing hypertools in Google Colab, users encountered:

ValueError: invalid literal for int() with base 10: '/usr/local/lib/python3'
UnboundLocalError: cannot access local variable 'working_backend' where it is not associated with a value

This occurred because jupyter notebook --version in Colab returns a path instead of a version number, and the version parsing code didn't handle this edge case.

Additionally, hdbscan (a dependency via umap-learn) has unescaped LaTeX backslashes in docstrings that trigger SyntaxWarning in Python 3.12+.

Changes

1. hypertools/plot/backend.py:

   • Add robust version parsing with try-except to handle malformed output
   • Initialize working_backend before any code that could raise exceptions
   • Add null check before tuple version comparison

2. hypertools/__init__.py:

   • Add warning filter to suppress hdbscan's SyntaxWarning on import

3. tests/test_backend.py (new):

   • Add regression tests for version parsing edge cases including Colab paths

Testing

• All 136 tests pass
• Manually verified in Google Colab - import now works cleanly with no errors or warnings