Support for babel > 2.8develop

Close #1400, #1219 and #1296.

2 files changed, 16 insertions, 3 deletions

diff --git a/pint/formatting.py b/pint/formatting.py
index a04205d..528f4e0 100644
--- a/pint/formatting.py
+++ b/pint/formatting.py
@@ -333,9 +333,14 @@ def formatter(
                     # Don't remove this positional! This is the format used in Babel
                     key = pat.replace("{0}", "").strip()
                     break
-            division_fmt = compound_unit_patterns.get("per", {}).get(
-                babel_length, division_fmt
-            )
+
+            tmp = compound_unit_patterns.get("per", {}).get(babel_length, division_fmt)
+
+            try:
+                division_fmt = tmp.get("compound", division_fmt)
+            except AttributeError:
+                division_fmt = tmp
+
             power_fmt = "{}{}"
             exp_call = _pretty_fmt_exponent
         if value == 1:
diff --git a/pint/testsuite/test_issues.py b/pint/testsuite/test_issues.py
index ed781b7..9d4167c 100644
--- a/pint/testsuite/test_issues.py
+++ b/pint/testsuite/test_issues.py
@@ -824,6 +824,14 @@ class TestIssues(QuantityTestCase):
         m = ureg.Measurement(1, 0.1, "meter")
         assert m.default_format == "~P"
 
+    def test_issue_1400(self, sess_registry):
+        q1 = 3 * sess_registry.W
+        q2 = 3 * sess_registry.W / sess_registry.cm
+        assert q1.format_babel("~", locale="es_Ar") == "3 W"
+        assert q1.format_babel("", locale="es_Ar") == "3 vatios"
+        assert q2.format_babel("~", locale="es_Ar") == "3.0 W / cm"
+        assert q2.format_babel("", locale="es_Ar") == "3.0 vatios por centímetros"
+
 
 if np is not None: