Split a string by spaces — preserving quoted substrings — in Python

I have a string which is like this:

this is "a test"

I’m trying to write something in Python to split it up by space while ignoring spaces within quotes. The result I’m looking for is:

['this','is','a test']

PS. I know you are going to ask “what happens if there are quotes within the quotes, well, in my application, that will never happen.