npm creates node_modules, package.json and package.lock locally, when `npm install` is ran, whichever directory you may be in.
pip lets you "capture" each dependency and write them to a file which someone else can install dependencies from.
go lets you use `go mod init` and related commands to create a Go file where all dependencies will be tracked. Running `go get` will update this file, but only if you ran `go mod init` before.
With zef, you have to write manually a JSON file. That sucks.