Significant chunks of numpy and scipy, the "main" python packages for numerical algorithms, are wrappers around classic libraries such as BLAS, LAPACK and ARPAC

Significant chunks of numpy and scipy, the "main" python packages for numerical algorithms, are wrappers around classic libraries such as BLAS, LAPACK and ARPACK, which are Fortran. Fortran was the de-facto language of scientific and numerical programming for a long time, back to the 60s even. These libraries are battle tested more than anything else out there, they literally have decades behind them, so they are industry standard and are used wherever possible.