Client Type for local Python script?

Client Type for local Python script?

Hello,

I'm writing a local script to get the contacts in a segment. I chose "Server Based Applications" as my client type, but I'm getting "invalid_client" error when requesting access token. 

I've double checked the request URL dc, and client id/secret multiple times. 

Did I pick the wrong client type? What client type should I be using for a local python script?