[genericpseudo]

By volume numpy is mostly assembler written to the Fortran ABI (it's a LAPACK/BLAS-etc wrapper).

[onalark]

NumPy is a library that provides typed multidimensional arrays and functions that run atop them. It does provide a built-in LAPACK/BLAS or can link externally to LAPACK/BLAS, but that's a side effect of providing typed arrays and is nowhere near the central purpose of the library.

Also, NumPy is implemented completely in C and Python, and makes extensive use of CPython extension hooks and knowledge of the CPython reference counting implementation, which is part of the reason why it is so hard to port to other implementations of Python.

[nine_k]

Having typed arrays without efficient functions over them would be rather pointless.

[filmor]

Are you sure you aren't mistaking numpy for scipy?

[ngrilly]

numpy is the foundation of scipy.