signfetch 0.2.0a1

Download data resources discovered via FAIR Signposting item links.

signfetch v0.2.0a1

Python package focused on discovering and downloading data via FAIR Signposting.

Scope

Version 0.2.0a1 exposes two public APIs:

• list_item_links(target) – discover item links without downloading
• download_data(target, output_dir=...) – discover and download data resources

Both functions use FAIR Signposting discovery mechanisms.

The package discovers item links from the three main Signposting delivery mechanisms:

1. HTTP Link headers
2. HTML <link> elements
3. Link Sets discoverable with the linkset relation

Link sets are automatically retrieved and parsed when present.

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Example – discover data resources

You can inspect available data resources without downloading them.

from signfetch import list_item_links

links = list_item_links(
    "https://doi.org/10.5281/zenodo.12542566"
)

for link in links:
    print(link.url, link.source)

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Example – download discovered data

download_data() performs discovery and downloads all discovered resources.

from pathlib import Path
from signfetch import download_data

result = download_data(
    "https://doi.org/10.5281/zenodo.12542566",
    output_dir=Path("downloads")
)

print(result.unique_item_count)

for item in result.items:
    print(item.url, item.saved_path)

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Design notes

Main components:

Signposting discovery

• SignpostingHarvester – orchestrates discovery
• LinkHeaderParser – parses HTTP Link headers
• HtmlLinkParser – parses HTML <link> elements
• LinksetParser – parses linkset documents

Downloading

• DataDownloader – downloads resources discovered via item links
• downloads are executed concurrently

Public API

• list_item_links() – discovery only
• download_data() – discovery + download

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Installation

pip install signfetch