How to Zoom with Axes3D in Matplotlib
Actually @tcaswell is correct that this functionality doesn't exist and so it returns false. Have you tried zoom-to-rectangle button on the plot window? That works perfectly. If you haven't yet, then refer to the matplotlib instructions on Interactive Navigation. You can zoom in using two ways:
Clicking on pan/zoom button:
Press the right mouse button to zoom, dragging it to a new position. The x axis will be zoomed in proportionate to the rightward movement and zoomed out proportionate to the leftward movement.
Clicking on zoom-to-rectangle button:
Put your mouse somewhere over and axes and press the left mouse button. Drag the mouse while holding the button to a new location and release.