Cleanups of the routing code:

* Move compare_all_but() into a utils file
* Eliminate a second loop from the compare_all_but() function.
* Rename unused variables from _ to dummy to avoid potential gettext
  conventions.
* rename remove_flatmapping_artefacts() to
  remove_flatmapping_artifacts() (artefacts is the British English spelling)

antsibull/docs_parsing/routing.py

@@ -19,6 +19,7 @@
 
 from .. import app_context
 from .. import yaml
+from ..utils.collections import compare_all_but
 from ..utils.get_pkg_data import get_antsibull_data
 from . import AnsibleCollectionMetadata
 from .fqcn import get_fqcn_parts
@@ -83,7 +84,7 @@ def find_symlink_redirects(collection_name: str,
     """
     plugin_type_routing = dict()
     if os.path.isdir(directory_path):
-        for path, _, files in os.walk(directory_path):
+        for path, dummy, files in os.walk(directory_path):
             rel_path = os.path.relpath(path, directory_path)
             for filename in files:
                 src_basename, ext = os.path.splitext(filename)
@@ -154,7 +155,7 @@ def find_flatmapping_short_long_maps(plugin_routing_type: t.Dict[str, t.Dict[str
     return shortname_to_longname, longname_to_shortname
 
 
-def remove_flatmapping_artefacts(plugin_routing: t.Dict[str, t.Dict[str, t.Dict[str, t.Any]]]
+def remove_flatmapping_artifacts(plugin_routing: t.Dict[str, t.Dict[str, t.Dict[str, t.Any]]]
                                  ) -> None:
     """
     For collections which use flatmapping (like community.general and community.network),
@@ -237,7 +238,7 @@ async def load_collection_routing(collection_name: str,
                 plugin_type_routing[redirect_name]['redirect_is_symlink'] = True
 
     if collection_name in COLLECTIONS_WITH_FLATMAPPING:
-        remove_flatmapping_artefacts(plugin_routing_out)
+        remove_flatmapping_artifacts(plugin_routing_out)
 
     return plugin_routing_out
 
@@ -265,24 +266,6 @@ async def load_all_collection_routing(collection_metadata: t.Mapping[str,
     return global_plugin_routing
 
 
-def compare_all_but(dict_a, dict_b, *keys_to_ignore):
-    """
-    Compare two dictionaries
-    """
-    sentinel = object()
-    for key, value in dict_a.items():
-        if key in keys_to_ignore:
-            continue
-        if value != dict_b.get(key, sentinel):
-            return False
-    for key, value in dict_b.items():
-        if key in keys_to_ignore:
-            continue
-        if value != dict_a.get(key, sentinel):
-            return False
-    return True
-
-
 def remove_redirect_duplicates(plugin_info: t.MutableMapping[str, t.MutableMapping[str, t.Any]],
                                collection_routing: CollectionRoutingT) -> None:
     """
@@ -299,8 +282,8 @@ def remove_redirect_duplicates(plugin_info: t.MutableMapping[str, t.MutableMappi
                     # Heuristic: if we have a redirect, and docs for both this plugin and the
                     # redirected one are generated from the same plugin filename, then we can
                     # remove this plugin's docs and generate a redirect stub instead.
-                    if compare_all_but(
-                            plugin_record['doc'], plugin_map[destination]['doc'], 'filename'):
+                    if compare_all_but(plugin_record['doc'], plugin_map[destination]['doc'],
+                                       'filename'):
                         del plugin_map[plugin_name]
 
 

antsibull/utils/collections.py

@@ -1,10 +1,10 @@
 # Author: Toshio Kuratomi <[email protected]>
 # License: GPLv3+
 # Copyright: Ansible Project, 2020
-"""General functions for working with collections and classes for new data types."""
+"""General functions for working with python collections and classes for new data types."""
 
 import typing as t
-from collections.abc import Sequence
+from collections.abc import Sequence, Set
 
 
 def is_sequence(obj: t.Any, include_string: bool = False) -> bool:
@@ -25,3 +25,36 @@ def is_sequence(obj: t.Any, include_string: bool = False) -> bool:
     if isinstance(obj, Sequence):
         return True
     return False
+
+
+def compare_all_but(dict_a: t.Mapping, dict_b: t.Mapping,
+                    keys_to_ignore: t.Iterable = None) -> bool:
+    """
+    Compare two dictionaries, with the possibility to ignore some fields.
+
+    :arg dict_a: First dictionary to compare
+    :arg dict_b: Second dictionary to compare
+    :kwarg keys_to_ignore: An iterable of keys whose values in the dictionaries will not be
+        compared.
+    :returns: True if the dictionaries have matching values for all of the keys which were not
+        ignored.  False otherwise.
+    """
+    if keys_to_ignore is None:
+        return dict_a == dict_b
+
+    if not isinstance(keys_to_ignore, Set):
+        keys_to_ignore = frozenset(keys_to_ignore)
+
+    length_a = len(frozenset(dict_a.keys()) - keys_to_ignore)
+    length_b = len(frozenset(dict_b.keys()) - keys_to_ignore)
+
+    if length_a != length_b:
+        return False
+
+    sentinel = object()
+
+    for key, value in ((k, v) for k, v in dict_a.items() if k not in keys_to_ignore):
+        if value != dict_b.get(key, sentinel):
+            return False
+
+    return True