Slightly simplify examples

docs/tutorial/tests/steps/library_steps.py

@@ -36,14 +36,15 @@ def these_books_in_the_catalog(
 
 
 @when(
+    # Step definitions could have parameters. Here could be raw stings, cucumber expressions or regular expressions
     re.compile('a (?P<search_type>name|title) search is performed for "(?P<search_term>.+)"'),
     target_fixture="search_results",
 )
 def a_search_type_is_performed_for_search_term(
     # `search_results` is a usual pytest fixture defined somewhere else and injected by pytest DI mechanism.
     # In this case it will be provided by conftest.py
     search_results,
-    # `search_type` and `search_term` are parameters of this step and is injected by step definition
+    # `search_type` and `search_term` are parameters of this step and are injected by step definition
     search_type: Literal["name", "title"],
     search_term: str,
     # `catalog` is a fixture injected by another step
@@ -60,6 +61,12 @@ def a_search_type_is_performed_for_search_term(
 
 
 @then("only these books will be returned")
-def only_these_books_will_be_returned(search_results, step: Step, catalog: Catalog):
+def only_these_books_will_be_returned(
+    # fixtures persist during step execution, so usual context is not required,
+    # so if you define fixture dependencies debugging becomes much easier.
+    search_results,
+    step: Step,
+    catalog: Catalog,
+):
     expected_books = get_books_from_data_table(step.data_table)
     assert all([book in catalog.storage for book in expected_books])