README.md update, cases.py reformat.

Add dotted path details and run with pytest to README.md Removed commented out code from cases.py.

README.md

@@ -342,6 +342,17 @@ apply doctest optionflags in --replmode.
 Do patching cleanup when not in --replmode by calling
 `unittest.addModuleCleanup(stack.pop_all().close)`.
 
+### Dotted path details
+
+The fixture function must be at the top level of a .py file.
+
+- The dotted_path has components separated by ".".
+- The last component is the function name.
+- The next to last component is the python file name without the .py suffix.
+- The preceding components identify parent folders. Folders should be
+  relative to the current working directory which is typically the
+  project root.
+
 ## Extend an example across files
 
 Names assigned by all the blocks in a file can be shared, as global variables,
@@ -446,6 +457,8 @@ breakage in future versions. Look for examples in tests/test_patching.py.
 - In repl mode **no** skipped blocks are rendered.
 - Try redirecting `--generate -` standard output into PYPI Pygments to
   colorize the generated test file.
+- pytest will run a generated test file (--generate TESTFILE). pytest won't
+  run functions added by unittest.addModuleCleanup().
 
 ## Related projects
 

src/phmutest/cases.py

@@ -331,17 +331,14 @@ def testfile(args: argparse.Namespace, block_store: phmutest.select.BlockStore)
     test_classes = ""
     replacements = {}
     if args.fixture:
-        # modulepackage, function_name = get_fixture_parts(args.fixture)
-        import_line = (
+        replacements["importuserfixture"] = (
             "from phmutest.importer import fixture_function_importer "
             "as _phm_fixture_function_importer"
         )
-        replacements["importuserfixture"] = import_line
-        call_line = (
+        replacements["calluserfixture"] = (
             f"_phm_user_setup_function = "
             f'_phm_fixture_function_importer("{args.fixture}")'
         )
-        replacements["calluserfixture"] = call_line
 
     if args.setup_across_files or args.share_across_files or args.fixture:
         setupcode = render_setup_module(args, block_store)