Access denied to my own files in client

Greetings:

I'm brand new to working with the Python SDK so if the answer is obvious please excuse the ignorance. I've created a client connection using the developer token and can execute all sorts of file and folder methods. But when I try to download a file using client.file(file_id).content() I get an Access Denied status (for a file that I uploaded and own) and when I try to get the metadata, using a known template I get a 404 not found for all available scopes. 

What am I missing? Is the developer token not sufficient for this? I was able to get the file ID and all sorts of folder content information but am stumped when it comes to downloading content or retrieving metadata.

Thanks!