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Python Performance: Why 'if not list' is 2x Faster Than Using len()
(blog.codingconfessions.com)
this post was submitted on 12 Apr 2025
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Technology
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I know I'm gonna get downvoted to oblivion for this, but... Serious question: why use Python if you're concerned about performance?
I’ve worked on a library that’s Python because the users of said library are used to Python.
The original version of the project made heavy use of numpy, so the actual performance sensitive code was effectively C++ and fourtran, which is what numpy is under the hood.
We eventually replaced the performance sensitive part of the code with Rust (and still some fourtran because BLAS) which ended up being about 10x faster.
The outermost layer of code is still Python though.