Refactor: simplify scientific() and extract _SUPERSCRIPT_MAP constant (#313)

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

src/humanize/number.py

@@ -18,6 +18,21 @@
     NumberOrString: TypeAlias = float | str
 
 
+_SUPERSCRIPT_MAP = {
+    "0": "⁰",
+    "1": "¹",
+    "2": "²",
+    "3": "³",
+    "4": "⁴",
+    "5": "⁵",
+    "6": "⁶",
+    "7": "⁷",
+    "8": "⁸",
+    "9": "⁹",
+    "-": "⁻",
+}
+
+
 def _format_not_finite(value: float) -> str:
     """Utility function to handle infinite and nan cases."""
     import math
@@ -415,19 +430,6 @@ def scientific(value: NumberOrString, precision: int = 2) -> str:
     """
     import math
 
-    exponents = {
-        "0": "⁰",
-        "1": "¹",
-        "2": "²",
-        "3": "³",
-        "4": "⁴",
-        "5": "⁵",
-        "6": "⁶",
-        "7": "⁷",
-        "8": "⁸",
-        "9": "⁹",
-        "-": "⁻",
-    }
     try:
         value = float(value)
         if not math.isfinite(value):
@@ -441,14 +443,7 @@ def scientific(value: NumberOrString, precision: int = 2) -> str:
     import re
 
     part2 = re.sub(r"^\+?(\-?)0*(.+)$", r"\1\2", part2)
-
-    new_part2 = []
-    for char in part2:
-        new_part2.append(exponents[char])
-
-    final_str = part1 + " x 10" + "".join(new_part2)
-
-    return final_str
+    return part1 + " x 10" + "".join([_SUPERSCRIPT_MAP[char] for char in part2])
 
 
 def clamp(