notebook: support changing total

[r786786]

import urllib, os
from tqdm.notebook import tqdm
urllib = getattr(urllib, 'request', urllib)

class TqdmUpTo(tqdm):
    """Provides `update_to(n)` which uses `tqdm.update(delta_n)`."""
    def update_to(self, b=1, bsize=1, tsize=None):
        """
        b  : int, optional
            Number of blocks transferred so far [default: 1].
        bsize  : int, optional
            Size of each block (in tqdm units) [default: 1].
        tsize  : int, optional
            Total size (in tqdm units). If [default: None] remains unchanged.
        """
        if tsize is not None:
            self.total = tsize
        return self.update(b * bsize - self.n)  # also sets self.n = b * bsize

eg_link = "https://sample-videos.com/zip/100mb.zip"
with TqdmUpTo(unit='B', unit_scale=True, unit_divisor=1024, miniters=1,
              desc=eg_link.split('/')[-1]) as t:  # all optional kwargs
    urllib.urlretrieve(eg_link, filename=os.devnull, reporthook=t.update_to, data=None)
    t.total = t.n

This is literally the same exact code as was presented in the readme page (https://github.com/tqdm/tqdm#hooks-and-callbacks) except instead of

from tqdm import tqdm

I inputted

from tqdm.notebook import tqdm

The issue I am getting is that the progress bar doesn't update until it finishes to 100% (turns green). Other than that, during the entire duration of the download, this is how the progress bar looks like:

Another thing to point out is that the figures work perfectly fine, it's just the visual interface is stuck at 0% it seems like.

I've tried this on both Google Colab and Jupyter notebook, same issue.

[casperdcl]

Hmm that's because there's no initial total. Actually I don't think notebook works at all when total is changing; so I've changed the issue title accordingly. (Note to self: related #1143 finally adding some notebook tests.)

Anyway in the meantime it's probably better to use the requests version anyway (further down in the documentation):

import requests, os
from tqdm.auto import tqdm

eg_link = "https://sample-videos.com/zip/100mb.zip"
response = requests.get(eg_link, stream=True)
with tqdm.wrapattr(open(os.devnull, "wb"), "write",
                   miniters=1, desc=eg_link.split('/')[-1],
                   total=int(response.headers.get('content-length', 0))) as fout:
    for chunk in response.iter_content(chunk_size=4096):
        fout.write(chunk)

[redbrain]

Still a bug on Colab today. Any updates?

[prohde]

This is still an issue in version 4.65.0. Any updates?