Looking at the docs for YouCompleteMe it relies on other plugins to do semantic completion for a lot of the languages it has.
Example for python from the docs:
YCM relies on the Jedi engine to provide completion and code navigation. By default, it will pick the version of Python running the ycmd server and use its sys.path. While this is fine for simple projects, this needs to be configurable when working with virtual environments or in a project with third-party packages. The next sections explain how to do that.
Does this mean that I need to have Jedi installed?
What I'm really getting at is does YouCompleteMe come with these semantic plugins or do they need to be installed seperately?