Historically, node-gyp has been the build tool of choice for the Node ecosystem. The tool comes bundled with Node and is nearly universally used to build Node native modules. Most of the examples on this site use node-gyp to build the binaries.
node-gyp is based upon Google’s GYP build tool. GYP, in turn, requires Python.
node-gyp requires Python 2.7 or Python 3.5+ depending upon the operating system on which the native module is being built. The specifics of the requirements can be found here.
For developers who find the node-gyp build tool too constraining, CMake.js is a good alternative.