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Description
“It is a truth universally acknowledged, that a module in possession of great colors, suffers import time slowdown.
_colorize module is slow to import due to its use of dataclasses
python -Ximporttime -c "import _colorize"Visualization in tuna
Notice that significant time is also spentexecuting the_colorize, due to the creation of its dataclasses
❯uvx python@3.15 -m cProfile -m _colorize| head -15 5609 function calls (5489 primitive calls) in 0.006 seconds Ordered by: cumulative time ncalls tottime percall cumtime percall filename:lineno(function) 9/1 0.003 0.000 0.006 0.006 {built-in method builtins.exec} 1 0.000 0.000 0.006 0.006 <string>:1(<module>) 1 0.000 0.000 0.006 0.006 <frozen runpy>:199(run_module) 1 0.000 0.000 0.006 0.006 <frozen runpy>:65(_run_code) 1 0.000 0.000 0.006 0.006 _colorize.py:1(<module>) 7 0.000 0.000 0.005 0.001 dataclasses.py:1432(wrap) 7 0.000 0.000 0.005 0.001 dataclasses.py:986(_process_class) 7 0.000 0.000 0.003 0.000 dataclasses.py:478(add_fns_to_class) 4 0.000 0.000 0.001 0.000 inspect.py:3342(signature) 4 0.000 0.000 0.001 0.000 inspect.py:3055(from_callable)
The slow import time directly affects (among others) thetraceback module which in turn affectslogging, which is 40% slower in 3.14 and 3.15 compared to 3.13. That is quite unfortunate since in applications that care about import time,logging module is typically hard to avoid (I originally discovered this when looking at pip's startup time)
hyperfine -w 10 "python3.13 -c 'import logging'" "python3.15 -c 'import logging'"Benchmark 1: python3.13 -c 'import logging' Time (mean ± σ): 21.0 ms ± 3.4 ms [User: 14.8 ms, System: 5.9 ms] Range (min … max): 16.2 ms … 28.2 ms 155 runsBenchmark 2: python3.15 -c 'import logging' Time (mean ± σ): 29.6 ms ± 2.1 ms [User: 22.2 ms, System: 7.0 ms] Range (min … max): 26.4 ms … 35.1 ms 100 runsSummary python3.13 -c 'import logging' ran 1.40 ± 0.25 times faster than /home/hollas/.local/share/uv/python/cpython-3.15.0a5-linux-x86_64-gnu/bin/python3.15 -c 'import logging'
It's not very clear how to make this better (besides not using dataclasses). We tried to make traceback lazy in logging, but failed.#112995