Couple more enhancements on conf sections

src/python/pimlico/cli/status.py

@@ -160,7 +160,7 @@ def run_command(self, pipeline, opts):
                         print("\n%s:" % status)
                         print("\n".join(status_lists[status]))
                 else:
-                    if not opts.no_sections or len(module_names) < 2:
+                    if not pipeline.has_sections or not opts.no_sections or len(module_names) < 2:
                         # Show with the structure of section headings
                         mod_name_bullets = dict(zip(module_names, bullets))
                         selected_subtree = pipeline.section_headings.subtree(module_names)
@@ -225,7 +225,7 @@ def print_section_tree(tree, mod_name_bullets, pipeline, depth=0, expand="all"):
         section_colors = [module_status_color(pipeline[mod]) for mod in tree.subtree_modules()]
         # Apply consistent sorting
         section_colors.sort()
-        print("\n{}{}".format(
+        print("{}{}".format(
             mix_bg_colors("{} {}. {}".format("#"*depth, tree.number_str(), tree.name), section_colors),
             title_suffix
         ))

src/python/pimlico/core/config.py

@@ -118,8 +118,11 @@ def __init__(self, name, pipeline_config, local_config,
             sys.path.extend(additional_paths)
 
         if section_headings is None:
-            section_headings = SectionHeadings("root", self.module_order, [])
+            section_headings = SectionHeadings("root", [], self.module_order, [])
         self.section_headings = section_headings
+        # Whether there is actually a structure of headings
+        # If it's really just a flat list, we won't try formatting headings later
+        self.has_sections = len(self.section_headings.subsections) > 0
 
         # Step mode is disabled by default: see method enable_step()
         self._stepper = None
@@ -2371,6 +2374,8 @@ def number_str(self):
         return ".".join(str(n) for n in self.number)
 
     def number_matches_subtree(self, number):
+        if len(number) == 0 or len(self.number) == 0:
+            return True
         return all(x == y for (x, y) in zip(number, self.number))
 
     def expand_module(self, old_name, new_names):