Added aastex.Variable class. (#4)

* Added `aastex.Variable` class.

* black

* docs

aastex/_aastex.py

@@ -24,6 +24,7 @@
     "Affiliation",
     "Author",
     "Acronym",
+    "Variable",
     "Abstract",
     "Section",
     "Subsection",
@@ -170,6 +171,39 @@ def dumps(self):
         return command
 
 
+@dataclasses.dataclass
+class Variable(pylatex.base_classes.LatexObject):
+    """
+    A wrapper around the ``\\newcommand`` LaTeX command.
+    """
+
+    name: str
+    """The name of the variable."""
+
+    value: float | u.Quantity
+    """The value of the variable."""
+
+    @property
+    def _name(self) -> str:
+        return NoEscape(f"\\{self.name}")
+
+    @property
+    def _value(self) -> str:
+        v = self.value
+        if isinstance(v, u.Quantity):
+            v = f"{v:latex_inline}"
+            v = rf"\ensuremath{{{v[1:~0]}}}"
+        else:
+            v = str(v)
+        return NoEscape(v)
+
+    def dumps(self) -> str:
+        return Command(
+            command="newcommand",
+            arguments=[self._name, self._value],
+        ).dumps()
+
+
 class Abstract(pylatex.base_classes.Environment):
     def __init__(
         self,

aastex/_tests/test_aastex.py

@@ -107,6 +107,25 @@ def test_dumps(self, a: aastex.Title):
         assert isinstance(a.dumps(), str)
 
 
+@pytest.mark.parametrize(
+    argnames="a",
+    argvalues=[
+        aastex.Variable("foo", 2),
+        aastex.Variable("bar", 3 * u.AA),
+    ],
+)
+class TestVariable:
+
+    def test_name(self, a: aastex.Variable):
+        assert isinstance(a.name, str)
+
+    def test_value(self, a: aastex.Variable):
+        assert isinstance(a.value, (int, float, u.Quantity))
+
+    def test_dumps(self, a: aastex.Variable):
+        assert isinstance(a.dumps(), str)
+
+
 @pytest.mark.parametrize(
     argnames="a",
     argvalues=[