There is no need to get paths but a similar feature,it's called segments I suppose.
plt.contourf(ds.TIME1,ds.DEPTH,ds.temp,levels=(np.arange(50,450,40)),cmap="hot)
contour = plt.contour(ds.TIME1,ds.DEPTH,ds.temp,levels=[23])
contour.allsegs[0][1] # this will give all the x,y data points for segment, and so on for rest of the segments.