It’s because Python object attributes can change any time, as they are accessed dynamically. Nothing can be inlined easily. The object structure is pointer heav

It’s because Python object attributes can change any time, as they are accessed dynamically. Nothing can be inlined easily. The object structure is pointer heavy. Here is some old 2014 post: http://jakevdp.github.io/blog/2014/05/09/why-python-is-slow/ http://jakevdp.github.io/blog/2014/05/09/why-python-is-slow/ As other commenters pointed out, some of these Python features, which are unused 99,99% time, could be sacrified for additional speedup by breaking backwards compatibility.