CMSIS-DSP is a general-purpose compute library with a focus on DSP. It was initially developed for Cortex-M processors and has recently been upgraded to also support Cortex-A.
On each processor, CMSIS-DSP is optimized for the architecture: DSP extensions on M4 and M7; Helium on M55 and M85; Neon on A55, etc.
The CMSIS-DSP Python package is a Python API for CMSIS-DSP. Its goal is to make it easier to develop a C solution using CMSIS-DSP by decreasing the gap between a design environment like Python and the final C implementation.
For this reason, the Python API is as close as possible to the C one.
Fixed-point arithmetic is rarely provided by Python packages, which generally focus on floating-point operations. The CMSIS-DSP Python package provides the same fixed-point arithmetic functions as the C version: Q31, Q15 and Q7. The package also provides floating-point functions and will also support half-precision floats in the future, like the C API.
Finally, the CMSIS-DSP Python package is compatible with NumPy and can be used with all other scientific and AI Python packages such as SciPy and PyTorch.