How should we handle the certificate when we create a python app which gets and sends data on https server?

The python script uses Urllib3 and my server is scripted on Node.js.I'm worrying (and not understanding clearly) about the certificate: Do I need to save as variable the certificate on my python app?

For example I did this,

http = urllib3.PoolManager(    cert_reqs="CERT_REQUIRED",    ca_certs='client-cert.pem')

and I don't know if this is the right way to do it, like it is secure way to do it, or it's okay if hacker gets the hands on certificate?

I successfully set up python app with Node.js in that way as I explained, I'm expecting the hacker to not get hands on the data being sent and recieved by app and server.