ref: dfb8d83c44195a8b97c06d6920b3fb8c4ed6cd19
dir: /sys/src/cmd/python/Tools/bgen/README/
BGEN -- Automatic Generation of Extension Modules ================================================= This directory contains BGEN -- a package that helps in generating complete source code for Python extension module. For examples of its use, see the Mac Python source distribution (available separately from the Python ftp archives). Note that BGEN is not Mac specific!