Chapter 3 questions

John6666
Tue, 23 Dec 2025 03:32:08 +0000

it tries to connect to server?

seems so.

In your Kaggle notebook, wandb.init(...) is very likely trying to start an online W&B run and set up syncing to the W&B backend. If Kaggle Internet is off or restricted, that can look like “loads forever.” W&B documents that mode="online" is the default for wandb.init, and that offline and disabled exist specifically for air-gapped or restricted environments. (Weights & Biases Documentation)

That SyntaxWarning from notebookapp.py is almost certainly unrelated noise. It does not explain the hang. Your hang is about networking or authentication, not that warning.

What is happening in the background

1) What wandb.init(...) does

Think of W&B as having two steps:

Auth step (optional): “Who are you?” via wandb.login() or an API key already stored.

Run step: “Create a run and start logging.” That is wandb.init(...).

In W&B’s own docs, wandb.init defaults to online syncing, and it is the point where W&B sets up the run and syncing behavior. (Weights & Biases Documentation)

So your understanding is correct: in default mode it is set up to connect to W&B’s service.

2) Why Kaggle triggers the “infinite loading” pattern

Kaggle notebooks have an “Internet” setting. Kaggle explicitly notes (a) you may need Internet enabled, and (b) some competitions require Internet to be disabled for submission. (Kaggle)

If Internet is disabled, any library that tries to reach an external service can hang, retry, or time out in ways that look like a stuck cell.

Also, some users cannot even see the “Internet on” toggle until phone verification is done. (Stack Overflow)

Why wandb.login() can hang in notebooks

wandb.login() often expects either:

an existing configured API key, or

a key you pass programmatically, or

an interactive prompt where you paste the key

In notebook environments, the interactive prompt can fail or never complete. W&B’s login() docs mention a UsageError when an API key cannot be configured and there is “no tty,” which is exactly the class of issue you can hit in hosted notebook environments. (Weights & Biases Documentation)

So “infinite waiting” usually means: it is waiting for key input or stuck in an auth flow that is not completing.

Do you need an API key from wandb.ai?

You need a W&B API key only if you want online logging to wandb.ai.

Online logging: yes, you need a key (or other auth) and you need Kaggle Internet enabled. W&B references the API key in their offline/online guidance too. (Weights & Biases Documentation)

Offline logging: no key needed. You log locally and can sync later from a machine with Internet. mode="offline" exists for this use case. (Weights & Biases Documentation)

Disabled: no key needed. W&B becomes a no-op. (Weights & Biases Documentation)

Clean fixes for Kaggle (pick one)

Option A: Internet must stay OFF (common in competitions)

Do not call wandb.login() at all. Force offline mode.

import os
os.environ["WANDB_MODE"] = "offline"  # set before importing/using wandb

import wandb
wandb.init(project="transformer-fine-tuning", name="bert-mrpc-analysis", mode="offline")

Why this works: W&B explicitly supports offline for air-gapped environments. (Weights & Biases Documentation)

Option B: You do not need W&B at all

Disable it.

import os
os.environ["WANDB_MODE"] = "disabled"

import wandb
wandb.init(mode="disabled")

W&B documents disabled as a supported mode (no-op). (Weights & Biases Documentation)

Option C: You want to use wandb.ai from Kaggle (Internet ON)

1. Enable Kaggle Internet in Notebook settings. Kaggle documents the Internet toggle and warns it must be off for some competitions. (Kaggle)

2. Ensure you can see the toggle. If you cannot, phone verification can be the blocker. (Stack Overflow)

3. Use a non-interactive login (avoid notebook prompts). Pass a key explicitly.

import os, wandb

# Put your key in Kaggle Secrets or env vars
wandb.login(key=os.environ["WANDB_API_KEY"], verify=True, timeout=60)

wandb.init(project="transformer-fine-tuning", name="bert-mrpc-analysis")

Why this is the right shape:

W&B login() supports key=... and has verify and timeout parameters. (Weights & Biases Documentation)

verify=True forces an immediate server check, so you fail fast if Internet is still blocked.

Two easy-to-miss context points

1. Hugging Face login is unrelated to W&B.
huggingface_hub.login() authenticates to Hugging Face. It does not authenticate to W&B. You still need a W&B key for wandb.ai online logging.

2. Your project name has a typo: "trasformer-fine-tuning" vs "transformer-fine-tuning".
This does not cause hanging, but it will create a project with the misspelled name if online logging succeeds.

If it still hangs after forcing offline

If mode="offline" still hangs, the next suspect is a local W&B background service startup problem (separate from Internet). W&B has many reports around “timed out waiting for wandb service to start.” (GitHub)
In that case, mode="disabled" is the fastest way to confirm whether W&B itself is the source of the stall.

Summary

Yes, default wandb.init() is online-mode behavior and can try to reach W&B servers. (Weights & Biases Documentation)

Kaggle often has Internet disabled (or required disabled for competitions), which makes W&B look stuck. (Kaggle)

wandb.login() can “wait forever” in notebooks because it is waiting for key input or has no TTY. (Weights & Biases Documentation)

You need a W&B API key only for wandb.ai online logging. Offline or disabled modes do not need it. (Weights & Biases Documentation)