python 3.6.3

ipykernel (4.6.1)
ipython (6.2.1)
jupyter (1.0.0)
jupyter-client (5.1.0)
jupyter-console (5.2.0)
jupyter-core (4.4.0)
tqdm (4.19.4)

All installed by pip3 on macOS 10.13.1 and Chrome 62.0.3202.94 (Official Build) (64-bit)

I am seeing extra spaces added on redrawing nested progress meters. The inner meters slowly creep farther from the top bar. Here is a quick script that demonstrates the problem:

import tqdm

address_space = set()

for i in tqdm.tqdm_notebook(range(256), desc='First Octet'):
    for j in tqdm.tqdm_notebook(range(256), desc='Second Octet', leave=False):
        for k in range(256):
            for l in range(256):
                address_space.add('{}.{}.{}.{}'.format(i, j, k, l))

If you substitute the third and fourth nested range(256) with more tqdm, the problem is even more obvious.

I have attached an animated GIF of the problem.