Google Colab (& Jupyter Lab) bug: nested bars duplicated at each iteration

[artemisart]

The output of google colab is a bit strange and it duplicate nested bars for each iteration:

from time import sleep
from tqdm import tqdm
for j in tqdm(range(3), desc='main',position=0):
    for i in tqdm(range(3), desc='inner', position=1):  # it's exactly the same output if I omit the position args
        sleep(0.1)

main:   0%|          | 0/3 [00:00<?, ?it/s]
inner:   0%|          | 0/3 [00:00<?, ?it/s]
inner:  33%|███▎      | 1/3 [00:00<00:00,  9.98it/s]
inner:  67%|██████▋   | 2/3 [00:00<00:00,  9.84it/s]
inner: 100%|██████████| 3/3 [00:00<00:00,  9.74it/s]
main:  33%|███▎      | 1/3 [00:00<00:00,  3.05it/s]
inner:   0%|          | 0/3 [00:00<?, ?it/s]
inner:  33%|███▎      | 1/3 [00:00<00:00,  9.98it/s]
inner:  67%|██████▋   | 2/3 [00:00<00:00,  9.86it/s]
inner: 100%|██████████| 3/3 [00:00<00:00,  9.69it/s]
main:  67%|██████▋   | 2/3 [00:00<00:00,  3.03it/s]
inner:   0%|          | 0/3 [00:00<?, ?it/s]
inner:  33%|███▎      | 1/3 [00:00<00:00,  9.98it/s]
inner:  67%|██████▋   | 2/3 [00:00<00:00,  9.85it/s]
inner: 100%|██████████| 3/3 [00:00<00:00,  9.77it/s]
main: 100%|██████████| 3/3 [00:00<00:00,  3.02it/s]

However forcing the position of the nested bars to 0 seem to solve the issue:

from time import sleep
from tqdm import tqdm
for j in tqdm(range(3), desc='main'):
    for i in tqdm(range(3), desc='inner', position=0):
        sleep(0.1)

inner: 100%|██████████| 3/3 [00:00<00:00,  9.89it/s]
inner: 100%|██████████| 3/3 [00:00<00:00,  9.90it/s]
inner: 100%|██████████| 3/3 [00:00<00:00,  9.90it/s]
main: 100%|██████████| 3/3 [00:00<00:00,  3.25it/s]

Version

> import tqdm, sys
> print(tqdm.__version__, sys.version, sys.platform)
4.26.0 3.6.3 (default, Oct  3 2017, 21:45:48) 
[GCC 7.2.0] linux

So is this the expected behaviour ? Could the position be automatically forced to 0 if the env is a notebook ?
For long iterations it can crash the browser tab (both Firefox and Chrome) because the bar is duplicated thousands of times and google colab output display must not be that optimized.

EDIT: in fact the issue is not only on google colab, I am able to reproduce the same outputs in jupyter lab & notebook.

[casperdcl]

duplicate of #558

[artemisart]

This is clearly not a duplicate as #558 is about tqdm_notebook with js widgets and the bug I encounter is about text (stdout) tqdm. And yes I searched for similar issues before posting this but I found nothing related to my problem.

[casperdcl]

Ah I see this is more like #428

[casperdcl]

See also nested https://github.com/tqdm/tqdm#faq-and-known-issues

[artemisart]

Indeed, but #428 doesn't provide an output example so I cannot really compare.
So is the problem "expected" for text output in notebooks ? Could tqdm detects that the output is a cell in a notebook and force position=0 ?

[casperdcl]

forcing position=0 would overwrite bars on top of each other, though.