Python: tqdm not showing progress bar

Question

I have written the PyTorch code for the fit function of my network. But when I use tqdm in the loop within it, it does not increase from 0% the reason for which I am unable to understand.

Here is the code:

from tqdm.notebook import tqdm

def fit(model, train_dataset, val_dataset, epochs=1, batch_size=32, warmup_prop=0, lr=5e-5):

    device = torch.device('cuda:1')
    model.to(device)
    
    train_loader = DataLoader(train_dataset, batch_size=batch_size, shuffle=True)
    val_loader = DataLoader(val_dataset, batch_size=batch_size, shuffle=False)

    optimizer = AdamW(model.parameters(), lr=lr)
    
    num_warmup_steps = int(warmup_prop * epochs * len(train_loader))
    num_training_steps = epochs * len(train_loader)
    
    scheduler = get_linear_schedule_with_warmup(optimizer, num_warmup_steps, num_training_steps)

    loss_fct = nn.BCEWithLogitsLoss(reduction='mean').to(device)
    
    for epoch in range(epochs):
        model.train()
        start_time = time.time()
        
        optimizer.zero_grad()
        avg_loss = 0
        
        for step, (x, y_batch) in tqdm(enumerate(train_loader), total=len(train_loader)): 
            y_pred = model(x.to(device))
            
            loss = loss_fct(y_pred.view(-1).float(), y_batch.float().to(device))
            loss.backward()
            avg_loss += loss.item() / len(train_loader)


            optimizer.step()
            scheduler.step()
            model.zero_grad()
            optimizer.zero_grad()
                
        model.eval()
        preds = []
        truths = []
        avg_val_loss = 0.

        with torch.no_grad():
            for x, y_batch in val_loader:                
                y_pred = model(x.to(device))
                loss = loss_fct(y_pred.detach().view(-1).float(), y_batch.float().to(device))
                avg_val_loss += loss.item() / len(val_loader)
                
                probs = torch.sigmoid(y_pred).detach().cpu().numpy()
                preds += list(probs.flatten())
                truths += list(y_batch.numpy().flatten())
            score = roc_auc_score(truths, preds)
            
        
        dt = time.time() - start_time
        lr = scheduler.get_last_lr()[0]
        print(f'Epoch {epoch + 1}/{epochs} \t lr={lr:.1e} \t t={dt:.0f}s \t loss={avg_loss:.4f} \t val_loss={avg_val_loss:.4f} \t val_auc={score:.4f}')

Output
The output after executing the fit function with the required parameters looks like this:
0%| | 0/6986 [00:00<?, ?it/s]

How to fix this?

Are you sure the entire function's execution has completed? Are the prints at the bottom of the loop executed? — GoodDeeds, May 14 '21 at 13:53
Yes, the entire function gets executed and I get the loss values as well, the code is running but there is no response in the progress bar @GoodDeeds — Ishan Dutta, May 14 '21 at 14:12
Does `tqdm` work in general? Try a sample example like in the answer of this post: https://stackoverflow.com/a/63427058/6025629 — Mike Xydas, May 14 '21 at 14:35

Arty · Accepted Answer · 2021-05-14T15:05:12.433

As you are importing from tqdm.notebook it means that you're using Jupyter notebook, right? If not you have to do from tqdm import tqdm.

I simplified your example code to make it really minimal, like this:

import time
from tqdm.notebook import tqdm

l = [None] * 10000

for i, e in tqdm(enumerate(l), total = len(l)): 
    time.sleep(0.01)

and executed on Google Colab jupyter notebook. It showed me nice progress bar like this:

So it means tqdm works in notebook mode correctly. Hence you have some problem with your iterable or loop code, not with tqdm. Possible reason could be that your inner loop takes to long time so even 1 iteration (out of total 6986 in your case) takes forever and is not showed in progress bar.

One more reason is that your iterable takes forever to produce second element, also you have to check if it works.

Also I see you showed us ASCII progress bar, which is not the one that is usually shown in Notebook (notebook shows graphical bar usually). So maybe you're not inside notebook at all? Then you have to do from tqdm import tqdm instead of from tqdm.notebook import tqdm.

Also first try to simplify your code, just temporarily, to figure out if reason was really with tqdm module in your case and not with your iterable or loop code. Try starting from my code provided above.

Also instead of tqdm try with just printing something like print(step) inside your loop, does it print at least two lines on the screen?

If in my code I do from tqdm import tqdm and then executing it in console Python then I get:

10%|███████████▉              | 950/10000 [00:14<02:20, 64.37it/s]

which means that console version works too.

This answer is a bit down-looking. Because it works on your installation does not imply it would work on OP's. And because it works in a console interpreter does not mean it has to work in a notebook. See this thread https://stackoverflow.com/questions/57343134/jupyter-notebooks-not-displaying-progress-bars for some possible fixes. — Aubergine, Aug 24 '21 at 09:57
@Aubergine As you can see in my answer I provided run of my code in Notebook (as screenshot), meaning that it works in notebook. I showed console version too just to prove that it works in console also. Also my answer was Accepted and UpVoted by OP, which most probably shows that he tested it on his notebook and it worked for him. — Arty, Aug 24 '21 at 10:28

score 3 · Answer 2 · answered Sep 06 '21 at 12:52

3

This can happen in Jupyter if the notebook is not trusted - if that's the case, click on "Not Trusted" box in the upper right corner.

answered Sep 06 '21 at 12:52

Maciej Budyś

31
2

Please add further details to expand on your answer, such as working code or documentation citations. – Community Sep 06 '21 at 12:55

score 1 · Answer 3 · edited Nov 21 '21 at 13:03

It because use from tqdm.notebook import tqdm instead of from tqdm import tqdm in terminal environment.

Provide a example to show this problem:

from tqdm.notebook import tqdm

if __name__ == '__main__':
    data = range(10000)
    for i, item in enumerate(tqdm(range(len(data)))):
        i = i + 1

It will show: enter image description here

However if you use this code sample:

from tqdm import tqdm

if __name__ == '__main__':
    data = range(10000)
    for i, item in enumerate(tqdm(range(len(data)))):
        i = i + 1

It will display: enter image description here

Python: tqdm not showing progress bar

3 Answers3