How are interpreted symbols escaped when searching Google in Vimium?

[arilebedey]

When searching for something that contains symbols that are interpreted by the Google search API as special characters, those characters are escaped. Here is an example: typing "#" in the vomnibar will perform the following search: "https://www.google.com/search?q=%23".

I would be interested to know how this escaping process is done in this project, as I would like to do the same in a Python script.