oeis-tools 0.2.0

A Python toolkit for programmatic access, analysis, and visualization of integer sequences from the OEIS (Online Encyclopedia of Integer Sequences).

oeis-tools

A focused Python toolkit for working with OEIS integer sequences: fetch metadata, parse b-files, and plot sequence values quickly.

Features

• Validate OEIS IDs like A000045
• Build canonical OEIS URLs and b-file names
• Fetch sequence JSON metadata via Sequence
• Fetch and parse b-file numeric data via BFile
• Plot b-file values with line or scatter styles

Requirements

• Python 3.9+
• Optional: matplotlib for plotting

Installation

pip install oeis-tools

For local development:

git clone https://github.com/oeistools/oeis-tools.git
cd oeis-tools
pip install -e ".[dev]"

Quick Start

Utility Functions

import oeis_tools as ot

print(ot.check_id("A000045"))                # True
print(ot.oeis_bfile("A000045"))              # b000045.txt
print(ot.oeis_url("A000045"))                # https://oeis.org/A000045
print(ot.oeis_url("A000045", fmt="json"))    # https://oeis.org/search?q=id:A000045&fmt=json

Sequence API

from oeis_tools import Sequence

seq = Sequence("A000045")

print(seq.id)         # A000045
print(seq.name)       # Fibonacci numbers
print(seq.data)       # [0, 1, 1, 2, 3, 5, ...]
print(seq.author)     # list[str]
print(seq.keyword)    # list[str]
print(seq.offset)     # list[int]
print(seq.link)       # parsed links as markdown-style text

info = seq.get_bfile_info()
print(info["available"], info["length"])

B-file API

from oeis_tools import BFile

bfile = BFile("A000045")

print(bfile.get_filename())   # b000045.txt
print(bfile.get_url())        # https://oeis.org/A000045/b000045.txt
print(bfile.get_bfile_data()) # list[int] or None
bfile.plot_data(50, show=False)                                # first 50 points
bfile.plot_data(50, show=False, plot_style="scatter")          # scatter plot
bfile.plot_data(50, show=False, plot_style="joined")           # joined/line plot
ax = bfile.plot_data(show=False, return_ax=True)               # matplotlib Axes

Plotting Examples

Overlay two sequences on one plot:

import matplotlib.pyplot as plt
import oeis_tools

N_POINTS = 200

bfile = oeis_tools.BFile("A114906")
bfile2 = oeis_tools.BFile("A114904")
fig, ax = plt.subplots()
bfile.plot_data(n=N_POINTS, ax=ax, show=False, color="red")
bfile2.plot_data(n=N_POINTS, ax=ax, show=True, color="blue")
plt.show()

Scatter versus joined:

import matplotlib.pyplot as plt
from oeis_tools import BFile

bfile = BFile("A000045")
fig, ax = plt.subplots()
bfile.plot_data(80, ax=ax, show=False, plot_style="scatter", color="black")
bfile.plot_data(80, ax=ax, show=False, plot_style="joined", color="orange")
plt.show()

API Summary

• check_id(oeis_id: str) -> bool
• oeis_bfile(oeis_id: str) -> str
• oeis_url(oeis_id: str, fmt: str | None = None) -> str
• Sequence(oeis_id: str)
• Sequence.get_bfile_info() -> dict
• BFile(oeis_id: str)
• BFile.get_filename() -> str
• BFile.get_url() -> str
• BFile.get_bfile_data() -> list[int] | None
• BFile.plot_data(n: int | None = None, show: bool = True, ax=None, return_ax: bool = False, plot_style: str = "line", **plot_kwargs)

Error Behavior

• Sequence(...) raises ValueError for invalid IDs.
• Sequence(...) propagates HTTP errors from the OEIS JSON endpoint.
• BFile.get_bfile_data() returns None when a b-file cannot be fetched or parsed.

Development

Run tests:

pytest -q

Run lint checks:

ruff format .
ruff check . --fix

Build distributions:

python -m build
python -m twine check dist/*

Contribution guide: see CONTRIBUTING.md.

Publishing

This repository includes a GitHub Actions publish workflow at .github/workflows/publish.yml.

• Automatic publish trigger: GitHub Release published
• Manual publish trigger: workflow_dispatch
• Upload target: PyPI via trusted publishing (id-token)

License

MIT. See LICENSE.