mhvk · Feb 17, 2023 · Feb 16, 2023 · Feb 16, 2023 · Feb 16, 2023
diff --git a/astropy/units/function/core.py b/astropy/units/function/core.py
@@ -378,7 +378,7 @@ def __pow__(self, power):
     def __pos__(self):
         return self._copy()
 
-    def to_string(self, format="generic"):
+    def to_string(self, format="generic", **kwargs):
         """
         Output the unit in the given format as a string.
 
@@ -391,23 +391,51 @@ def to_string(self, format="generic"):
             The name of a format or a formatter object.  If not
             provided, defaults to the generic format.
         """
-        if format not in ("generic", "unscaled", "latex", "latex_inline"):
+        supported_formats = (
+            "generic",
+            "unscaled",
+            "latex",
+            "latex_inline",
+            "unicode",
+            "console",
+        )
+        if format not in supported_formats:
             raise ValueError(
                 f"Function units cannot be written in {format} "
-                "format. Only 'generic', 'unscaled', 'latex' and "
-                "'latex_inline' are supported."
+                f"format. Only {', '.join(supported_formats)} are supported."
             )
-        self_str = self.function_unit.to_string(format)
-        pu_str = self.physical_unit.to_string(format)
+        self_str = self.function_unit.to_string(format, **kwargs)
+        pu_str = self.physical_unit.to_string(format, **kwargs)
         if pu_str == "":
             pu_str = "1"
         if format.startswith("latex"):
             # need to strip leading and trailing "$"
             self_str += rf"$\mathrm{{\left( {pu_str[1:-1]} \right)}}$"
         else:
-            self_str += f"({pu_str})"
+            pu_lines = pu_str.splitlines()
+            if len(pu_lines) == 1:
+                self_str += f"({pu_str})"
+            else:
+                # If the physical unit is formatted into a multiline
+                # string, the lines need to be adjusted so that the
+                # functional string is aligned with the fraction line
+                # (second one), and all other lines are indented
+                # accordingly.
+                f = f"{{0:^{len(self_str)+1}s}}{{1:s}}"
+                lines = [
+                    f.format("", pu_lines[0]),
+                    f.format(f"{self_str}(", f"{pu_lines[1]})"),
+                ] + [f.format("", line) for line in pu_lines[2:]]
+                self_str = "\n".join(lines)
         return self_str
 
+    def __format__(self, format_spec):
+        """Try to format units using a formatter."""
+        try:
+            return self.to_string(format=format_spec)
+        except ValueError:
+            return format(str(self), format_spec)
+
     def __str__(self):
         """Return string representation for unit."""
         self_str = str(self.function_unit)

diff --git a/astropy/units/tests/test_format.py b/astropy/units/tests/test_format.py
@@ -818,3 +818,33 @@ def test_celsius_fits():
     assert u.Unit("deg C kg-1", format="fits") == u.C * u.deg / u.kg
     assert u.Unit("Celsius kg-1", format="fits") == u.deg_C / u.kg
     assert u.deg_C.to_string("fits") == "Celsius"
+
+
+@pytest.mark.parametrize(
+    "format_spec, string",
+    [
+        ("generic", "dB(1 / m)"),
+        ("unscaled", "dB(1 / m)"),
+        ("latex", r"$\mathrm{dB}$$\mathrm{\left( \mathrm{\frac{1}{m}} \right)}$"),
+        ("latex_inline", r"$\mathrm{dB}$$\mathrm{\left( \mathrm{m^{-1}} \right)}$"),
+        ("console", "dB(m^-1)"),
+        ("unicode", "dB(m⁻¹)"),
+    ],
+)
+def test_function_format_styles(format_spec, string):
+    dbunit = u.decibel(u.m**-1)
+    assert dbunit.to_string(format_spec) == string
+    assert f"{dbunit:{format_spec}}" == string
+
+
+@pytest.mark.parametrize(
+    "format_spec, inline, string",
+    [
+        ("console", False, "    1\ndB( -)\n    m"),
+        ("unicode", False, "    1\ndB( ─)\n    m"),
+        ("latex", True, r"$\mathrm{dB}$$\mathrm{\left( \mathrm{m^{-1}} \right)}$"),
+    ],
+)
+def test_function_format_styles_inline(format_spec, inline, string):
+    dbunit = u.decibel(u.m**-1)
+    assert dbunit.to_string(format_spec, inline=inline) == string
diff --git a/docs/changes/units/14407.feature.rst b/docs/changes/units/14407.feature.rst
@@ -0,0 +1,2 @@
+Allow "console" and "unicode" formats for conversion to string of
+function units.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Allow "console" and "unicode" formats for conversion to string of
		function units.