d2l-ai/d2l-zh · error · AssertionError

只有zip/tar文件可以被解压缩

Error message

只有zip/tar文件可以被解压缩

What it means

An AssertionError (assert False) in d2l.tensorflow.download_extract that fires when the downloaded file's extension is neither .zip nor .tar/.gz. The function only knows how to open archives via zipfile.ZipFile or tarfile.open; any other extension aborts with the Chinese message 'only zip/tar files can be extracted'.

Source

Thrown at d2l/tensorflow.py:395

    print(f'正在从{url}下载{fname}...')
    r = requests.get(url, stream=True, verify=True)
    with open(fname, 'wb') as f:
        f.write(r.content)
    return fname

def download_extract(name, folder=None):
    """下载并解压zip/tar文件

    Defined in :numref:`sec_kaggle_house`"""
    fname = download(name)
    base_dir = os.path.dirname(fname)
    data_dir, ext = os.path.splitext(fname)
    if ext == '.zip':
        fp = zipfile.ZipFile(fname, 'r')
    elif ext in ('.tar', '.gz'):
        fp = tarfile.open(fname, 'r')
    else:
        assert False, '只有zip/tar文件可以被解压缩'
    fp.extractall(base_dir)
    return os.path.join(base_dir, folder) if folder else data_dir

def download_all():
    """下载DATA_HUB中的所有文件

    Defined in :numref:`sec_kaggle_house`"""
    for name in DATA_HUB:
        download(name)

DATA_HUB['kaggle_house_train'] = (
    DATA_URL + 'kaggle_house_pred_train.csv',
    '585e9cc93e70b39160e7921475f9bcd7d31219ce')

DATA_HUB['kaggle_house_test'] = (
    DATA_URL + 'kaggle_house_pred_test.csv',
    'fa19780a7b011d9b009e8bff8e99922a8ee2eb90')

View on GitHub (pinned to e6b18ccea7)

Solutions

1. For plain files (csv/json/txt), call d2l.download(name) instead of download_extract(name) — no extraction is needed.
2. For .bz2/.xz archives, pre-extract manually (tar xjf file.tar.bz2) or register a .zip/.tar.gz mirror in DATA_HUB.
3. Fix the registered URL so it ends with a real archive extension before calling download_extract.
4. For .tar.bz2 specifically, note os.path.splitext returns '.bz2'; rename or handle with tarfile.open(fname, 'r:bz2') in your own code.

Example fix

# before
d2l.DATA_HUB['raw_csv'] = (d2l.DATA_URL + 'data.csv', sha1)
fname = d2l.download_extract('raw_csv')  # AssertionError: csv is not zip/tar
# after
fname = d2l.download('raw_csv')  # plain download, no extraction

import os
_, ext = os.path.splitext(fname)
if ext in ('.zip', '.tar', '.gz'):
    out = d2l.download_extract(name)
elif ext in ('.csv', '.json', '.txt'):
    out = d2l.download(name)
else:
    raise ValueError(f'unsupported extension {ext!r}; extract {fname} manually')

def is_extractable(fname: str) -> bool:
    return os.path.splitext(fname)[1] in ('.zip', '.tar', '.gz')

try:
    d2l.download_extract(name)
except AssertionError as e:
    if 'zip/tar' in str(e):
        path = d2l.download(name)  # plain file, no extraction needed
    else:
        raise

When it happens

Trigger: Registering a DATA_HUB entry whose URL ends in .csv, .json, .txt, .pt, or .7z and then calling download_extract on it; a URL with no filename extension at all (query-string URLs); double-extension files where os.path.splitext picks up the wrong part (e.g. 'data.tar.bz2' yields '.bz2').

Common situations: Users pointing DATA_HUB at raw CSVs (correct target is download(), not download_extract()); .bz2 or .xz compressed archives from non-D2L sources; URLs like https://host/file?format=zip whose splitext result is ''.

Related errors

• 只有zip/tar文件可以被解压缩
• 只有zip/tar文件可以被解压缩
• 只有zip/tar文件可以被解压缩
• f"{name} 不存在于 {DATA_HUB}"
• f"{name} 不存在于 {DATA_HUB}"

AI-assisted analysis of d2l-ai/d2l-zh@e6b18ccea7 (2026-08-14). Data as JSON: /api/errors/cd2bfaab88d697ce. Report an issue: GitHub.