Predict Cox model survival function with error

Question

I’m using the lifelines package to fit a Cox model to my data. For new cases, I would like to predict my survival function and median survival time (or for any specific percentile for that matter) including the predictions for the upper and lower limits of the coefficients. I can find the limits in the summary of the model, but no easy way to predict with them. How can I do this? Should I just replace the coefficients with one of the limits and save it as a new model? Not my favorite solution, so if anyone has a better suggestion…