feedparser-rs 0.4.2

High-performance RSS/Atom/JSON Feed parser with feedparser-compatible API

feedparser-rs

High-performance RSS/Atom/JSON Feed parser for Python with feedparser-compatible API.

Features

• Fast: Native Rust implementation via PyO3
• HTTP fetching: Built-in URL fetching with compression (gzip, deflate, brotli)
• Conditional GET: ETag/Last-Modified support for efficient polling
• Tolerant parsing: Bozo flag for graceful handling of malformed feeds
• Multi-format: RSS 0.9x/1.0/2.0, Atom 0.3/1.0, JSON Feed 1.0/1.1
• Podcast support: iTunes and Podcast 2.0 namespace extensions
• feedparser-compatible: Dict-style access, field aliases, same API patterns
• DoS protection: Built-in resource limits

Installation

pip install feedparser-rs

[!IMPORTANT] Requires Python 3.9 or later.

Usage

Basic Parsing

import feedparser_rs

# Parse from string, bytes, or URL (auto-detected)
d = feedparser_rs.parse('<rss>...</rss>')
d = feedparser_rs.parse(b'<rss>...</rss>')
d = feedparser_rs.parse('https://example.com/feed.xml')  # URL auto-detected

# Attribute-style access (feedparser-compatible)
print(d.feed.title)
print(d.version)  # "rss20", "atom10", etc.
print(d.bozo)     # True if parsing errors occurred

# Dict-style access (feedparser-compatible)
print(d['feed']['title'])
print(d['entries'][0]['link'])

for entry in d.entries:
    print(entry.title)
    print(entry.published_parsed)  # time.struct_time

[!NOTE] Date fields like published_parsed return time.struct_time for feedparser compatibility.

Fetching from URL

import feedparser_rs

# Option 1: Auto-detection (recommended)
d = feedparser_rs.parse('https://example.com/feed.xml')

# Option 2: Explicit URL function
d = feedparser_rs.parse_url('https://example.com/feed.xml')

# With conditional GET for efficient polling
d = feedparser_rs.parse(
    'https://example.com/feed.xml',
    etag=cached_etag,
    modified=cached_modified
)
if d.status == 304:
    print("Feed not modified")

# With custom limits
limits = feedparser_rs.ParserLimits(max_entries=100)
d = feedparser_rs.parse_with_limits('https://example.com/feed.xml', limits=limits)

[!TIP] URL fetching supports automatic compression (gzip, deflate, brotli) and follows redirects.

Migration from feedparser

feedparser-rs is designed as a drop-in replacement for Python feedparser:

# Drop-in replacement
import feedparser_rs as feedparser

# Same API patterns work
d = feedparser.parse('https://example.com/feed.xml')
print(d.feed.title)
print(d['feed']['title'])  # Dict-style access works too
print(d.entries[0].link)

# Deprecated field names supported
print(d.feed.description)  # → d.feed.subtitle
print(d.channel.title)     # → d.feed.title
print(d.items[0].guid)     # → d.entries[0].id

Supported Field Aliases

Old Name	Maps To
feed.description	feed.subtitle or feed.summary
feed.tagline	feed.subtitle
feed.copyright	feed.rights
feed.modified	feed.updated
channel	feed
items	entries
entry.guid	entry.id
entry.description	entry.summary
entry.issued	entry.published

Advanced Usage

Custom Resource Limits

import feedparser_rs

limits = feedparser_rs.ParserLimits(
    max_feed_size_bytes=50_000_000,  # 50 MB
    max_entries=5_000,
    max_authors=20,
    max_links_per_entry=50,
)

d = feedparser_rs.parse_with_limits(feed_data, limits=limits)

Format Detection

import feedparser_rs

version = feedparser_rs.detect_format(feed_data)
print(version)  # "rss20", "atom10", "json11", etc.

Podcast Support

import feedparser_rs

d = feedparser_rs.parse(podcast_feed)

# iTunes metadata
if d.feed.itunes:
    print(d.feed.itunes.author)
    print(d.feed.itunes.categories)

# Episode metadata
for entry in d.entries:
    if entry.itunes:
        print(f"Duration: {entry.itunes.duration}s")

API Reference

Functions

• parse(source, etag=None, modified=None, user_agent=None) — Parse feed from bytes, str, or URL (auto-detected)
• parse_url(url, etag=None, modified=None, user_agent=None) — Fetch and parse feed from URL
• parse_with_limits(source, etag=None, modified=None, user_agent=None, limits=None) — Parse with custom resource limits
• parse_url_with_limits(url, etag=None, modified=None, user_agent=None, limits=None) — Fetch and parse with custom limits
• detect_format(source) — Detect feed format without full parsing

Classes

• FeedParserDict — Parsed feed result (supports both attribute and dict-style access)

  • .feed / ['feed'] — Feed metadata
  • .entries / ['entries'] — List of entries
  • .bozo — True if parsing errors occurred
  • .version — Feed version string
  • .encoding — Character encoding
  • .status — HTTP status code (for URL fetches)
  • .etag — ETag header (for conditional GET)
  • .modified — Last-Modified header (for conditional GET)

• ParserLimits — Resource limits configuration

Performance

Benchmarks vs Python feedparser on Apple M1 Pro:

Operation	feedparser-rs	Python feedparser	Speedup
Parse 2 KB RSS	0.01 ms	0.9 ms	90x
Parse 20 KB RSS	0.09 ms	8.5 ms	94x
Parse 200 KB RSS	0.94 ms	85 ms	90x

[!TIP] For maximum performance, pass bytes instead of str to avoid UTF-8 re-encoding.

Platform Support

Pre-built wheels available for:

Platform	Architecture
macOS	Intel (x64), Apple Silicon (arm64)
Linux	x64, arm64
Windows	x64

Supported Python versions: 3.9, 3.10, 3.11, 3.12, 3.13

Development

git clone https://github.com/bug-ops/feedparser-rs
cd feedparser-rs/crates/feedparser-rs-py
pip install maturin
maturin develop

License

Licensed under either of:

• Apache License, Version 2.0
• MIT License

at your option.

Links

• GitHub
• PyPI
• Rust API Documentation
• Changelog