Utilities that allow your library to download files from the Hub are referred to as downstream utilities. This guide introduces additional downstream utilities you can integrate with your library, or use separately on their own. You will learn how to:

hf_hub_url

Use hf_hub_url to retrieve the URL of a specific file to download by providing a filename.

>>> from huggingface_hub import hf_hub_url
>>> hf_hub_url(repo_id="lysandre/arxiv-nlp", filename="config.json")
'https://huggingface.co/lysandre/arxiv-nlp/resolve/main/config.json'

Specify a particular file version by providing the file revision. The file revision can be a branch, a tag, or a commit hash.

When using the commit hash, it must be the full-length hash instead of a 7-character commit hash:

>>> hf_hub_url(repo_id="lysandre/arxiv-nlp", filename="config.json", revision="877b84a8f93f2d619faa2a6e514a32beef88ab0a")
'https://huggingface.co/lysandre/arxiv-nlp/resolve/877b84a8f93f2d619faa2a6e514a32beef88ab0a/config.json'

hf_hub_url(repo_id="lysandre/arxiv-nlp", filename="config.json", revision="main")

Specify a file revision with a tag identifier. For example, if you want v1.0 of the config.json file:

hf_hub_url(repo_id="lysandre/arxiv-nlp", filename="config.json", revision="v1.0")

cached_download

cached_download is useful for downloading and caching a file on your local disk. Once stored in your cache, you don’t have to redownload the file the next time you use it. cached_download is a hands-free solution for staying up to date with new file versions. When a downloaded file is updated in the remote repository, cached_download will automatically download and store it for you.

Begin by retrieving your file URL with hf_hub_url, and then pass the specified URL to cached_download to download the file:

>>> from huggingface_hub import hf_hub_url, cached_download
>>> config_file_url = hf_hub_url("lysandre/arxiv-nlp", filename="config.json")
>>> cached_download(config_file_url)
'/home/lysandre/.cache/huggingface/hub/bc0e8cc2f8271b322304e8bb84b3b7580701d53a335ab2d75da19c249e2eeebb.066dae6fdb1e2b8cce60c35cc0f78ed1451d9b341c78de19f3ad469d10a8cbb1'

hf_hub_url and cached_download work hand in hand to download a file. This is precisely how hf_hub_download from the tutorial works! hf_hub_download is simply a wrapper that calls both hf_hub_url and cached_download.

>>> from huggingface_hub import hf_hub_download
>>> hf_hub_download(repo_id="lysandre/arxiv-nlp", filename="config.json")

snapshot_download

snapshot_download downloads an entire repository at a given revision. Like cached_download, all downloaded files are cached on your local disk. However, even if only a single file is updated, the entire repository will be redownloaded.

>>> from huggingface_hub import snapshot_download
>>> snapshot_download(repo_id="lysandre/arxiv-nlp")
'/home/lysandre/.cache/huggingface/hub/lysandre__arxiv-nlp.894a9adde21d9a3e3843e6d5aeaaf01875c7fade'

snapshot_download downloads the latest revision by default. If you want a specific repository revision, use the revision parameter as shown with hf_hub_url.

>>> from huggingface_hub import snapshot_download
>>> snapshot_download(repo_id="lysandre/arxiv-nlp", revision="main")

In general, it is usually better to manually download files with hf_hub_download (if you already know the file name) to avoid re-downloading an entire repository. snapshot_download is helpful when your library’s downloading utility is a helper, and unaware of which files need to be downloaded.

However, you don’t want to always download the contents of an entire repository with snapshot_download. Even if you don’t know the file name and only know the file type, you can download specific files with allow_regex and ignore_regex. use of the allow_regex and ignore_regex arguments to specify which files shall be downloaded. allow_regex and ignore_regex accept either a single regex or a list of regexes. The regex matching is based on fnmatch which means it provides support for Unix shell-style wildcards.

For example, you can use allow_regex to only download JSON configuration files:

>>> from huggingface_hub import snapshot_download
>>> snapshot_download(repo_id="lysandre/arxiv-nlp", allow_regex="*.json")

On the other hand, ignore_regex can be used to exclude certain files from being downloaded. The following example ignores the .msgpack and .h5 file extensions: or .h5 extensions, you could make use of ignore_regex:

>>> from huggingface_hub import snapshot_download
>>> snapshot_download(repo_id="lysandre/arxiv-nlp", ignore_regex=["*.msgpack", "*.h5"])

Passing a regex can be especially useful when repositories contain files that are never expected to be downloaded by snapshot_download.

Note that passing allow_regex or ignore_regex does not prevent snapshot_download from re-downloading the entire model repository if an ignored file is changed.

title: How to download files from the Hub

How to integrate downstream utilities in your library

hf_hub_url

cached_download

snapshot_download