Fix for print when no dimension coordinate data

Changelog.rst

@@ -1,3 +1,14 @@
+Version 1.9.?.?
+---------------
+
+**2022-0?-??**
+
+* Fixed bug that caused `cf.Domain.__str__` to fail when a dimension
+  coordinate construct does not have data
+  (https://github.com/NCAS-CMS/cfdm/issues/174)
+
+----
+
 Version 1.9.0.2
 ---------------
 

cfdm/domain.py

@@ -187,15 +187,18 @@ def _print_item(self, cid, variable, axes):
 
         x = []
         dimension_coordinates = self.dimension_coordinates(todict=True)
-        for axis_cid in sorted(self.domain_axes(todict=True)):
+        for axis_cid, axis in sorted(self.domain_axes(todict=True).items()):
             for cid, dim in dimension_coordinates.items():
                 if construct_data_axes[cid] == (axis_cid,):
                     name = dim.identity(default=f"key%{0}")
-                    y = f"{name}({dim.get_data().size})"
+                    y = f"{name}({axis.get_size()})"
                     if y != axis_names[axis_cid]:
                         y = f"{name}({axis_names[axis_cid]})"
+
                     if dim.has_data():
                         y += f" = {dim.get_data()}"
+                    else:
+                        y += " = "
 
                     x.append(y)
 

cfdm/test/test_Domain.py

@@ -42,6 +42,13 @@ def test_Domain__repr__str__dump(self):
         for title in (None, "title"):
             d.dump(display=False, _title=title)
 
+        # Test when dimension coordinate has no data
+        d = d.copy()
+        t = d.construct("time")
+        t.del_data()
+        self.assertFalse(t.has_data())
+        str(d)
+
     def test_Domain__init__(self):
         """Test the Domain constructor and source keyword."""
         cfdm.Domain(source="qwerty")

joss/paper.bib

@@ -40,10 +40,10 @@ @misc{Eaton:2020
   title = {{{NetCDF Climate}} and {{Forecast}} ({{CF}}) {{Metadata Conventions v1}}.8},
   publisher = {{CF Conventions Committee}},
   author = {{Eaton}, Brian and {Gregory}, Jonathan and {Drach}, Bob and {Taylor}, Karl and {Hankin}, Steve and {Caron}, John and {Signell}, Rich and {Bentley}, Phil and {Rappa}, Greg and {H{\"o}ck}, Heinke and {Pamment}, Alison and {Juckes}, Martin and {Raspaud}, Martin and {Horne}, Randy and {Whiteaker}, Timothy and {Blodgett}, David and {Zender}, Charlie and {Lee}, Daniel},
-  month = feb,
-  year = 2020,
-  urldate = {2020-07-27},
-  url = {http://cfconventions.org/Data/cf-conventions/cf-conventions-1.8/cf-conventions.html},
+  month = sep,
+  year = 2021,
+  urldate = {2020-09-10},
+  url = {http://cfconventions.org/Data/cf-conventions/cf-conventions-1.9/cf-conventions.html},
 }
 
 @software{Hassell2:2020,