~/talk

Pandas from the inside

Talkat PyData London 2016 · 2016-05-06..05-08· [python, developer-experience]
links:none on file
slides:none on file

Shows how DataFrames are implemented: data lives in numpy-backed block manager chunks, not as boxed Python objects, so single-column access is cheap — selecting a Series is ~2 μs — while building new DataFrames from columns costs much more. Demonstrates concrete memory savings (thousands vs tens of thousands of bytes), the pitfall of view vs copy and the strange setting-with-copy warning, and a practical speed contrast for aggregation — groupby+concat 200 ms vs 4 ms — plus a brief note that Dask solves out-of-memory distribution.

AI-written summary · about

  1. 0:00Introduction
  2. 1:10Talk goals and pandas overview
  3. 3:00Python vs NumPy memory and performance
  4. 8:28NumPy two-dimensional arrays
  5. 12:24Pandas origins and NumPy
  6. 15:37Pandas data structures and complexity
  7. 20:43Typical pandas workflow
  8. 26:04Loading data into DataFrame
  9. 27:49DataFrame structure
  10. 31:27Selecting DataFrame columns
  11. 36:28Block managers and caching
  12. 38:41Column selection internals
  13. 41:53Reformatting columns and indexes
  14. 44:25Multi-indexes display
  15. 45:09How indexes work
  16. 46:38Index alignment in operations
  17. 49:31Efficient row subset selection
  18. 51:38Adding columns and warnings
  19. 54:05Calculating wins, draws, losses
  20. 55:31GroupBy subtotaling
  21. 57:45Conclusions and performance
  22. 59:48Q&A
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