python-slow-why

Why Python Is Slow (and When It Doesn't Matter)

Video: https://youtu.be/YrXYRiVGork
Written version: https://cloudexplainers.com/why-python-is-slow-and-when-it-doesn-t-matter/

Everything below ran for real in the video. Run it in a throwaway machine or container, never on a computer you care about.

Lab files

The machine the video used, as files you can build it from:

• lab/builtin.py
• lab/bytecode.py
• lab/loop.c
• lab/loop.py
• lab/numpy_sum.py
• lab/sizes.py
• lab/threads.py
• lab/web_request.py

Commands, in the order the video runs them

The problem

# ana@laptop:~/shop$
python3 loop.py
gcc -O2 -o loop loop.c
./loop

Reason 1: the interpreter

# ana@laptop:~/shop$
python3 bytecode.py

Reason 2: everything is an object

# ana@laptop:~/shop$
python3 sizes.py

Reason 3: the GIL

# ana@laptop:~/shop$
python3 threads.py

How Python code goes fast

# ana@laptop:~/shop$
python3 builtin.py
python3 numpy_sum.py
pypy3 loop.py

When it doesn't matter

# ana@laptop:~/shop$
python3 web_request.py

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From Cloud Explainers. Lab files are MIT licensed (see the repository's LICENSE).