Drop numeral dependency, inline Roman numeral helpers

Replace the numeral package with ~30 lines of int2roman()/roman2int()
in _statics.py. Reduces supply chain surface. Fixes #47.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pyproject.toml

@@ -21,7 +21,6 @@ classifiers = [
     "Programming Language :: Python :: 3.13",
 ]
 dependencies = [
-    "numeral",
     "sounddevice",
     "scipy",
 ]

pytheory/_statics.py

@@ -2,6 +2,43 @@ import math
 
 REFERENCE_A = 440
 
+# ── Roman numeral helpers (replaces `numeral` package) ───────────────────
+
+_ROMAN_MAP = [
+    (1000, "M"), (900, "CM"), (500, "D"), (400, "CD"),
+    (100, "C"), (90, "XC"), (50, "L"), (40, "XL"),
+    (10, "X"), (9, "IX"), (5, "V"), (4, "IV"), (1, "I"),
+]
+
+_ROMAN_VALUES = {
+    "I": 1, "V": 5, "X": 10, "L": 50, "C": 100, "D": 500, "M": 1000,
+}
+
+
+def int2roman(n: int) -> str:
+    """Convert an integer to an uppercase Roman numeral string."""
+    result = []
+    for value, numeral in _ROMAN_MAP:
+        while n >= value:
+            result.append(numeral)
+            n -= value
+    return "".join(result)
+
+
+def roman2int(s: str) -> int:
+    """Convert a Roman numeral string (case-insensitive) to an integer."""
+    s = s.upper()
+    total = 0
+    prev = 0
+    for ch in reversed(s):
+        val = _ROMAN_VALUES.get(ch, 0)
+        if val < prev:
+            total -= val
+        else:
+            total += val
+        prev = val
+    return total
+
 # Index of C in the Western tone list (A=0, A#=1, B=2, C=3, ...).
 # Scientific pitch notation changes octave at C, not A, so this offset
 # is needed for all octave arithmetic.

pytheory/chords.py

@@ -849,7 +849,7 @@ class Chord:
             >>> Chord([D4, F4, A4]).analyze("C")
             'ii'
         """
-        import numeral as numeral_mod
+        from ._statics import int2roman
         from .scales import TonedScale
         from .systems import SYSTEMS
         from .tones import Tone
@@ -874,7 +874,7 @@ class Chord:
         scale_names = [t.name for t in scale.tones[:-1]]
 
         def _build_numeral(root, quality, degree_idx, prefix=""):
-            numeral_str = numeral_mod.int2roman(degree_idx + 1, only_ascii=True)
+            numeral_str = int2roman(degree_idx + 1)
             suffix = ""
             if "minor" in quality:
                 numeral_str = numeral_str.lower()

pytheory/scales.py

@@ -2,8 +2,6 @@ from __future__ import annotations
 
 from typing import Optional, Union
 
-import numeral
-
 from .systems import SYSTEMS, System
 from .tones import Tone
 
@@ -49,7 +47,8 @@ class Scale:
     def __repr__(self) -> str:
         r = []
         for (i, tone) in enumerate(self.tones):
-            degree = numeral.int2roman(i + 1, only_ascii=True)
+            from ._statics import int2roman
+            degree = int2roman(i + 1)
             r += [f"{degree}={tone.full_name}"]
 
         r = " ".join(r)
@@ -200,7 +199,7 @@ class Scale:
             >>> scale.progression("I", "IV", "V", "I")
             [<Chord (C,E,G)>, <Chord (F,A,C)>, <Chord (G,B,D)>, <Chord (C,E,G)>]
         """
-        import numeral as numeral_mod
+        from ._statics import roman2int
         chords = []
         for num in numerals:
             is_seventh = num.endswith("7")
@@ -213,7 +212,7 @@ class Scale:
             elif clean.startswith("#") and len(clean) > 1:
                 clean = clean[1:]
                 flat_offset = 1  # one semitone up
-            degree = numeral_mod.roman2int(clean.upper()) - 1
+            degree = roman2int(clean.upper()) - 1
             if is_seventh:
                 chord = self.seventh(degree)
             else:
@@ -406,7 +405,8 @@ class Scale:
         if isinstance(item, str):
             degrees = []
             for (i, tone) in enumerate(self.tones):
-                degrees.append(numeral.int2roman(i + 1, only_ascii=True))
+                from ._statics import int2roman
+                degrees.append(int2roman(i + 1))
 
             if item in degrees:
                 item = degrees.index(item)

uv.lock

@@ -486,14 +486,6 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/d3/ac/686789b9145413f1a61878c407210e41bfdb097976864e0913078b24098c/myst_parser-5.0.0-py3-none-any.whl", hash = "sha256:ab31e516024918296e169139072b81592336f2fef55b8986aa31c9f04b5f7211", size = 84533, upload-time = "2026-01-15T09:08:16.788Z" },
 ]
 
-[[package]]
-name = "numeral"
-version = "0.1.0.17"
-source = { registry = "https://pypi.org/simple" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/17/0d/ac6a186e169fcbdfea316f78fb5e34981bcf8d5c1d7cc8b6581f597e1e4c/numeral-0.1.0.17-py2.py3-none-any.whl", hash = "sha256:7dff0c1efb9b3655c9c1dc93b4666993741b15abcac0dc01dcb96b21cc20f6ae", size = 22066, upload-time = "2020-04-12T08:24:59.129Z" },
-]
-
 [[package]]
 name = "numpy"
 version = "2.2.6"
@@ -701,7 +693,6 @@ name = "pytheory"
 version = "0.38.2"
 source = { editable = "." }
 dependencies = [
-    { name = "numeral" },
     { name = "scipy", version = "1.15.3", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.11'" },
     { name = "scipy", version = "1.17.1", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.11'" },
     { name = "sounddevice" },
@@ -721,7 +712,6 @@ docs = [
 
 [package.metadata]
 requires-dist = [
-    { name = "numeral" },
     { name = "scipy" },
     { name = "sounddevice" },
 ]