Move dictionaries to class level

The dictionaries are constant so can be shared by any and all instances
of this class. Moving them into the class definition, but outside of the
__init__ allows that to happen.

Author: php1ic

src/nuclearmasses/utils/converter.py

@@ -9,30 +9,6 @@
 # Typing hint Union for the different ways a file or data can be represented
 DataInput = Traversable | os.PathLike[str] | str | typing.TextIO
 
-UNIT_TO_SECONDS: dict[str, float] = {
-    # Base SI and common
-    "s": 1.0,
-    "ms": 1e-3,
-    "us": 1e-6,
-    "ns": 1e-9,
-    "ps": 1e-12,
-    "as": 1e-18,
-    "zs": 1e-21,
-    "ys": 1e-24,
-    "min": 60.0,
-    "h": 3600.0,
-    "d": 86400.0,
-    "yr": 31_557_600.0,  # 365.25 days
-    "kyr": 3.15576e10,
-    "myr": 3.15576e13,
-    "gyr": 3.15576e16,
-    "zyr": 3.15576e21,
-    "eyr": 3.15576e18,
-    "pyr": 3.15576e15,
-    "tyr": 3.15576e12,
-    "yyr": 3.15576e24,
-}
-
 
 class Converter:
     """A utility class for converting between symbol and Z value
@@ -41,46 +17,72 @@ class Converter:
     and the other symbol to Z.
     """
 
+    UNIT_TO_SECONDS: dict[str, float] = {
+        "s": 1.0,
+        "ms": 1e-3,
+        "us": 1e-6,
+        "ns": 1e-9,
+        "ps": 1e-12,
+        "as": 1e-18,
+        "zs": 1e-21,
+        "ys": 1e-24,
+        "min": 60.0,
+        "h": 3600.0,
+        "d": 86400.0,
+        "yr": 31_557_600.0,  # 365.25 days
+        "kyr": 3.15576e10,
+        "myr": 3.15576e13,
+        "gyr": 3.15576e16,
+        "zyr": 3.15576e21,
+        "eyr": 3.15576e18,
+        "pyr": 3.15576e15,
+        "tyr": 3.15576e12,
+        "yyr": 3.15576e24,
+    }
+
+    # fmt: off
+    # Formatter wants to put each item on it's own line, I don't
+    Z_TO_SYMBOL: dict[int, str] = {
+        0: "n", 1: "H", 2: "He", 3: "Li", 4: "Be", 5: "B", 6: "C", 7: "N", 8: "O", 9: "F",
+        10: "Ne", 11: "Na", 12: "Mg", 13: "Al", 14: "Si", 15: "P", 16: "S", 17: "Cl", 18: "Ar", 19: "K",
+        20: "Ca", 21: "Sc", 22: "Ti", 23: "V", 24: "Cr", 25: "Mn", 26: "Fe", 27: "Co", 28: "Ni", 29: "Cu",
+        30: "Zn", 31: "Ga", 32: "Ge", 33: "As", 34: "Se", 35: "Br", 36: "Kr", 37: "Rb", 38: "Sr", 39: "Y",
+        40: "Zr", 41: "Nb", 42: "Mo", 43: "Tc", 44: "Ru", 45: "Rh", 46: "Pd", 47: "Ag", 48: "Cd", 49: "In",
+        50: "Sn", 51: "Sb", 52: "Te", 53: "I", 54: "Xe", 55: "Cs", 56: "Ba", 57: "La", 58: "Ce", 59: "Pr",
+        60: "Nd", 61: "Pm", 62: "Sm", 63: "Eu", 64: "Gd", 65: "Tb", 66: "Dy", 67: "Ho", 68: "Er", 69: "Tm",
+        70: "Yb", 71: "Lu", 72: "Hf", 73: "Ta", 74: "W", 75: "Re", 76: "Os", 77: "Ir", 78: "Pt", 79: "Au",
+        80: "Hg", 81: "Tl", 82: "Pb", 83: "Bi", 84: "Po", 85: "At", 86: "Rn", 87: "Fr", 88: "Ra", 89: "Ac",
+        90: "Th", 91: "Pa", 92: "U", 93: "Np", 94: "Pu", 95: "Am", 96: "Cm", 97: "Bk", 98: "Cf", 99: "Es",
+        100: "Fm", 101: "Md", 102: "No", 103: "Lr", 104: "Rf", 105: "Db", 106: "Sg", 107: "Bh", 108: "Hs", 109: "Mt",
+        110: "Ds", 111: "Rg", 112: "Cn", 113: "Ed", 114: "Fl", 115: "Ef", 116: "Lv", 117: "Ts", 118: "Og"
+    }
+    # fmt: on
+
+    # Switch the keys and values of the z_to_symbol dictionary so a user can access the Z value using the symbol
+    SYMBOL_TO_Z: dict[str, int] = {val: key for key, val in Z_TO_SYMBOL.items()}
+
     def __init__(self, **kwargs) -> None:
         """Construct the symbol -> Z and Z -> symbol dictionaries."""
         # We are using multiple inheritance, so need this for MRO
         super().__init__(**kwargs)
-        # fmt: off
-        # Formatter wants to put each item on it's own line, I don't
-        self.z_to_symbol: dict[int, str] = {
-            0: "n", 1: "H", 2: "He", 3: "Li", 4: "Be", 5: "B", 6: "C", 7: "N", 8: "O", 9: "F",
-            10: "Ne", 11: "Na", 12: "Mg", 13: "Al", 14: "Si", 15: "P", 16: "S", 17: "Cl", 18: "Ar", 19: "K",
-            20: "Ca", 21: "Sc", 22: "Ti", 23: "V", 24: "Cr", 25: "Mn", 26: "Fe", 27: "Co", 28: "Ni", 29: "Cu",
-            30: "Zn", 31: "Ga", 32: "Ge", 33: "As", 34: "Se", 35: "Br", 36: "Kr", 37: "Rb", 38: "Sr", 39: "Y",
-            40: "Zr", 41: "Nb", 42: "Mo", 43: "Tc", 44: "Ru", 45: "Rh", 46: "Pd", 47: "Ag", 48: "Cd", 49: "In",
-            50: "Sn", 51: "Sb", 52: "Te", 53: "I", 54: "Xe", 55: "Cs", 56: "Ba", 57: "La", 58: "Ce", 59: "Pr",
-            60: "Nd", 61: "Pm", 62: "Sm", 63: "Eu", 64: "Gd", 65: "Tb", 66: "Dy", 67: "Ho", 68: "Er", 69: "Tm",
-            70: "Yb", 71: "Lu", 72: "Hf", 73: "Ta", 74: "W", 75: "Re", 76: "Os", 77: "Ir", 78: "Pt", 79: "Au",
-            80: "Hg", 81: "Tl", 82: "Pb", 83: "Bi", 84: "Po", 85: "At", 86: "Rn", 87: "Fr", 88: "Ra", 89: "Ac",
-            90: "Th", 91: "Pa", 92: "U", 93: "Np", 94: "Pu", 95: "Am", 96: "Cm", 97: "Bk", 98: "Cf", 99: "Es",
-            100: "Fm", 101: "Md", 102: "No", 103: "Lr", 104: "Rf", 105: "Db", 106: "Sg", 107: "Bh", 108: "Hs", 109: "Mt", # noqa: E501
-            110: "Ds", 111: "Rg", 112: "Cn", 113: "Ed", 114: "Fl", 115: "Ef", 116: "Lv", 117: "Ts", 118: "Og"
-        }
-        # fmt: on
-
-        # Switch the keys and values of the z_to_symbol dictionary so a user can access the Z value using the symbol
-        self.symbol_to_z: dict[str, int] = {val: key for key, val in self.z_to_symbol.items()}
-
-    def get_symbol(self, z: int) -> str | None:
+
+    @staticmethod
+    def get_symbol(z: int) -> str | None:
         """Get the symbol representing <z>
 
         This is a nicely named, very thin wrapper around the inbuilt dictionary.
         I'm sure I was going to do something else in this function beyond basic accessing, but don't recall.
         Leave as is and hopefully I'll remember
         """
-        return self.z_to_symbol.get(z, None)
+        return Converter.Z_TO_SYMBOL.get(z, None)
 
-    def get_z(self, symbol: str) -> int | None:
+    @staticmethod
+    def get_z(symbol: str) -> int | None:
         """Get the z (proton number) representing <symbol>
 
         This is a nicely named, very thin wrapper around the inbuilt dictionary.
         """
-        return self.symbol_to_z.get(symbol, None)
+        return Converter.SYMBOL_TO_Z.get(symbol, None)
 
     @staticmethod
     def normalise_symbol(symbol: str) -> str:
@@ -94,7 +96,8 @@ def normalise_symbol(symbol: str) -> str:
         """
         return symbol.strip().title()
 
-    def unit_to_seconds(self, unit_str: str) -> float:
+    @staticmethod
+    def unit_to_seconds(unit_str: str) -> float:
         """Convert a time unit to a scale factor in seconds.
 
         Returns np.nan for non-valid time units.
@@ -113,7 +116,7 @@ def unit_to_seconds(self, unit_str: str) -> float:
         if not cleaned_unit:
             return np.nan
 
-        return UNIT_TO_SECONDS.get(cleaned_unit, np.nan)
+        return Converter.UNIT_TO_SECONDS.get(cleaned_unit, np.nan)
 
     @staticmethod
     def read_fwf(base: DataInput, **kwargs):