Make inflection package truly optional (#9303)

* Make inflection package truly optional

Fix #9291

* Make inflection compat layer consistent with the others

Co-authored-by: T. Franzel <13507857+tfranzel@users.noreply.github.com>

---------

Co-authored-by: T. Franzel <13507857+tfranzel@users.noreply.github.com>

docs/api-guide/schemas.md

@@ -56,10 +56,11 @@ The following sections explain more.
 
 ### Install dependencies
 
-    pip install pyyaml uritemplate
+    pip install pyyaml uritemplate inflection
 
 * `pyyaml` is used to generate schema into YAML-based OpenAPI format.
 * `uritemplate` is used internally to get parameters in path.
+* `inflection` is used to pluralize operations more appropriately in the list endpoints.
 
 ### Generating a static schema with the `generateschema` management command
 

rest_framework/compat.py

@@ -46,6 +46,12 @@ try:
 except ImportError:
     yaml = None
 
+# inflection is optional
+try:
+    import inflection
+except ImportError:
+    inflection = None
+
 
 # requests is optional
 try:

rest_framework/schemas/openapi.py

@@ -14,7 +14,7 @@ from django.utils.encoding import force_str
 from rest_framework import (
     RemovedInDRF315Warning, exceptions, renderers, serializers
 )
-from rest_framework.compat import uritemplate
+from rest_framework.compat import inflection, uritemplate
 from rest_framework.fields import _UnvalidatedField, empty
 from rest_framework.settings import api_settings
 
@@ -247,9 +247,8 @@ class AutoSchema(ViewInspector):
                 name = name[:-len(action)]
 
         if action == 'list':
-            from inflection import pluralize
-
-            name = pluralize(name)
+            assert inflection, '`inflection` must be installed for OpenAPI schema support.'
+            name = inflection.pluralize(name)
 
         return name