# How hard would it be to implement Numpy.jl, i.e. Numpy in Julia?

**URL:** <https://discourse.julialang.org/t/how-hard-would-it-be-to-implement-numpy-jl-i-e-numpy-in-julia/22080>\
**Category:** Numerics\
**Tags:** faq, python\
**Created:** [March 19, 2019, 10:48pm UTC](https://discourse.julialang.org/t/how-hard-would-it-be-to-implement-numpy-jl-i-e-numpy-in-julia/22080 "2019-03-19T22:48:54Z")\
**Posts on this page:** 1\
**Showing post:** 52

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**Author:** ![Pierre\_Augier](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pierre_augier/32/7506_2.png) [@Pierre\_Augier](https://discourse.julialang.org/u/Pierre_Augier)\
**Post date:** [March 22, 2019, 10:36am UTC](https://discourse.julialang.org/t/how-hard-would-it-be-to-implement-numpy-jl-i-e-numpy-in-julia/22080/52 "2019-03-22T10:36:01Z")

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> [@stevengj](#):
>
> Basically, the transpiler idea is attractive to people who don’t understand why compiling Python effectively is hard (which you have admitted repeatedly — you think a Python program provides the “same amount of information” as a Julia program and you “don’t understand” the idea that there are differences in language semantics that affect compilers), so they don’t see why there is a benefit to switching front-end languages.

I’m not a specialist in languages and programming but I never wrote that “I don’t understand the idea that there are differences in language semantics that affect compilers”. Please do not deform my words. It’s really not nice.

I don’t understand what is so wrong in terms of performance in the semantic of Python / Numpy used for efficient numerical kernels. And of course, one should not use extensible arrays of references (Python list) for critical parts of numerical kernels, and it is not a problem of a particular language. It is also possible to write very inefficient things in Julia.

I would be very interested to understand why for these simple computations (no user-def types) the Julia language (not the interpreter) is so much better. I think I need to study examples in numerical kernels used in the real life and compare the semantics. A Pythran challenge would definitively be interesting.

I’m going to stop with this discussion now. Thank you for your answers. Bye.

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