How to use a service account with Google's python api and drive?

Question

I try to write python 2.7 script to upload a file into my personal google drive folder.

After several problems I stuck know. This is my current error:

Answer 1

I found the answer in this gist:

openssl pkcs12 -passin pass:notasecret -in privatekey.p12 -nocerts -passout pass:notasecret -out key.pem
openssl pkcs8 -nocrypt -in key.pem -passin pass:notasecret -topk8 -out privatekey.pem
rm key.pem

But before this, I had to regenerate a new privat key but in P12 format.