feat(python): Update BytecodeParser for upcoming Python 3.13

[alexander-beedie]

Still mildly painful to install/debug under the Python 3.13rc1, but here's another update for the BytecodeParser, building on #16304. Might be the last one needed, but will have to wait on the final release to be sure 🤔

We now recognise specific "superinstructions"¹ and unpack them to their underlying component instructions (eg: LOAD_FAST_LOAD_FAST→LOAD_FAST+LOAD_FAST).

from polars._utils.udfs import BytecodeParser

bp = BytecodeParser(
    function = lambda x: (x/x) * (x+x),
    map_target = "expr",
)

• Python 3.11/3.12 bytecode for the example UDF/lambda given above:

  bp.dis()
  # 4    0 RESUME                   0
  #      2 LOAD_FAST                0 (x)
  #      4 LOAD_FAST                0 (x)
  #      6 BINARY_OP               11 (/)
  #     10 LOAD_FAST                0 (x)
  #     12 LOAD_FAST                0 (x)
  #     14 BINARY_OP                0 (+)
  #     18 BINARY_OP                5 (*)
  #     22 RETURN_VALUE

• Python 3.13 bytecode (note presence of superinstructions):

  bp.dis()
  # 4   RESUME                   0
  #     LOAD_FAST_LOAD_FAST      0 (x, x)
  #     BINARY_OP               11 (/)
  #     LOAD_FAST_LOAD_FAST      0 (x, x)
  #     BINARY_OP                0 (+)
  #     BINARY_OP                5 (*)
  #     RETURN_VALUE             

• Result (across all Python versions):

  bp.to_expression("x")
  # (pl.col("x") / pl.col("x")) * (pl.col("x") + pl.col("x"))

Footnotes

1. https://github.com/faster-cpython/ideas/issues/16 ↩

[codecov]

Codecov Report

Attention: Patch coverage is 57.14286% with 3 lines in your changes missing coverage. Please review.

Project coverage is 79.93%. Comparing base (149d6b9) to head (1aa0c4a).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
py-polars/polars/_utils/udfs.py	57.14%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #18677      +/-   ##
==========================================
+ Coverage   79.91%   79.93%   +0.01%     
==========================================
  Files        1513     1513              
  Lines      203310   203317       +7     
  Branches     2892     2896       +4     
==========================================
+ Hits       162467   162512      +45     
+ Misses      40293    40254      -39     
- Partials      550      551       +1     

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