I commonly run into a couple kinds of training partners, in the gym and especially in martial arts. They are "the competitor" and "the teammate."
The competitors are the partners who go hard and try to win at sparring. They want to get in more reps than you and lift heavier than you. They are driven to succeed and outdo. They want to chase you if you're ahead and stay in the lead if they're in front.
The teammaters are the partners who try to go as hard as you need them to. They'll try to train at your level and within your needs. They're much less driven to outdo, and see success by either you or themselves as success by both. They'll encourage you when you need help.
Both are very useful training partners - but they aren't always the one you need at a specific moment. Sometimes you need someone who'll drive you and sometimes you need someone who'll support you. Sometimes you need someone who'll smoke you at every lift to drive you to work harder. Sometimes you need someone who'll encourage your successes or pitch in to help you get where you need to go even if they aren't up to your level.