API Authorization Question

Hey guys, 

Can someone explain how I can pull this API info with python or point me in the right direction?

On the swagger documentation page for the API I am trying to access, I go to the header authentication section; paste in the API key, and am returned with a 'Base XXXXXXXXXXXX" key. Which I learned is an encoded base64 key. Then I paste the Basic key into the API key input filed in another section (See screenshot) and am successful in pulling the API information.  

However, I cannot figure out how to pull that information with python requests or postman. When I google "Pulling API with basic API key" It says I need a username and password. 

Any help would be appreciated. I'm a total noob.