Sonnet Checker

A small command-line tool and library that checks whether a poem matches the structural rules of a sonnet — Shakespearean, Petrarchan, or Spenserian — by verifying line count, rhyme scheme, and meter.

What it checks

• Line count — the poem has exactly 14 lines.
• Rhyme scheme — line-ending words are looked up in the CMU Pronouncing Dictionary (via the pronouncing package) and grouped by rhyme sound.
• Meter — each line's syllables are counted and compared against 10 (iambic pentameter). Meter checking is a syllable-count verification only (it does not verify stress patterning).

Quickstart (development)

python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
# optional: install editable for development
pip install -e .

Usage (CLI)

python app.py

The CLI runs interactively: choose a sonnet form and paste your poem, then press Enter twice to finish. The tool prints a pass/fail report.

Demo (asciinema)

A recorded asciinema cast is included in the repository at demo.cast. To preview the demonstration locally:

# install asciinema if you don't have it
# https://asciinema.org/docs/installation
asciinema play demo.cast

Live player embed

<iframe src="https://asciinema.org/a/Gr8UpHi6XEW5w8g6/embed" style="width: 100%; height: 320px; border: 0;"></iframe>

If the embed doesn't render on GitHub you can view the cast at https://asciinema.org/a/Gr8UpHi6XEW5w8g6 or convert the cast to an SVG/GIF for inline embedding (instructions below).

To convert the cast to an SVG or GIF for embedding in the README you can use svg-term and an image converter:

# npm install -g svg-term-cli
svg-term --in demo.cast --out demo.svg --window
# convert svg to gif (ImageMagick / other tools)
convert demo.svg demo.gif

If you prefer an online player you can upload demo.cast to https://asciinema.org and embed the player instead of a GIF.

Programmatic usage

from sonnet_checker.parser import parse_poem
from sonnet_checker.validators import validate_sonnet

text = open("my_sonnet.txt").read()
lines = parse_poem(text)
result = validate_sonnet(lines, "shakespearean")
print(result)  # dictionary with structure, rhyme, and meter results

Short example

• Line count and meter pass, rhyme scheme can fail due to:
  • Pronunciation strictness (modern pronunciation vs historical eye-rhyme).
  • Unknown end words (archaic elisions not present in CMUdict).

See EXAMPLES.md for a full Sonnet 18 transcript and detailed example output.

Running tests

python -m pytest

Project layout

app.py                    CLI entry point
sonnet_checker/
  sonnet_types.py         Line count / rhyme scheme / meter rules per form
  parser.py               Splits raw poem text into lines
  structure.py            Line count check
  rhyme.py                Rhyme scheme check
  meter.py                Syllable-count meter check
  validators.py           Runs the checks and assembles the result
tests/                    pytest suite for each module

How it works (concise)

• Rhyme matching: requires the rhyme sound from the last stressed vowel onward (CMUdict). Exact match is required by default.
• Unknown words: words missing from CMUdict are reported as "unknown" and cannot satisfy rhyme matches.
• Meter: checks syllable counts per line; for words missing from CMUdict the checker falls back to a vowel-group heuristic — this is inherently approximate.
• Rhyme and meter checks run only if line count passes.

Known limitations

• Exact CMUdict rhyme matching will flag historical near-rhymes (eye rhymes) as failures.
• Archaic/elided spellings (e.g., dimm'd) may not be in CMUdict.
• Meter checking does not verify stress patterns (true scansion).

Contributing

• Fork the repo, create a branch, run tests, and open a pull request.
• Suggested Dev workflow:
  • pip install -e .
  • run pytest and add tests for any change.
• If you’d like, I can add a CONTRIBUTING.md and issue templates in the PR.

Roadmap (high level)

• Optional fuzzy rhyme matching for historical near-rhymes
• Normalizing archaic elided spellings before dictionary lookup
• Stress-pattern-aware meter checking
• Web interface or a small web UI on top of the same package

License

This project is available under the MIT License. (I can add a LICENSE file to the branch and PR.)