Compiling the SIMD version of python-rapidjson

A recent task had me taking a look at alternative JSON libraries for the purpose of performance. One of them was python-rapidjson which offered support for SIMD.


To get python-rapidjson to compile with SIMD, we need to define one of the SIMD macros, either , , or .

The chosen flag would then need to be passed to pip during install via . Depending on the flag, you would have to pass some addition options.

  • SSE2:
  • SSE4.2:

One-liner to re-install the currently installed version as the SIMD version.

CFLAGS="-DRAPIDJSON_SSE42=1 -msse4.2" pip -v install -force-reinstall -no-binary python-rapidjson $(pip freeze | grep python-rapidjson)

The Adventures of Me

The Adventures of Me