Extract changes.

Author: tobiasraabe

docs/source/changes.md

@@ -14,6 +14,7 @@ releases are available on [PyPI](https://pypi.org/project/pytask-parallel) and
 - {pull}`92` redirects stdout and stderr from processes and loky and shows them in error
   reports.
 - {pull}`93` adds documentation on readthedocs.
+- {pull}`94` implements `ParallelBackend.NONE` as the default backend.
 
 ## 0.4.1 - 2024-01-12
 

src/pytask_parallel/backends.py

@@ -84,8 +84,6 @@ def _get_thread_pool_executor(n_workers: int) -> Executor:
 class ParallelBackend(Enum):
     """Choices for parallel backends."""
 
-    NONE = "none"
-
     CUSTOM = "custom"
     DASK = "dask"
     LOKY = "loky"

src/pytask_parallel/build.py

@@ -26,7 +26,7 @@ def pytask_extend_command_line_interface(cli: click.Group) -> None:
             ["--parallel-backend"],
             type=EnumChoice(ParallelBackend),
             help="Backend for the parallelization.",
-            default=ParallelBackend.NONE,
+            default=ParallelBackend.LOKY,
         ),
     ]
     cli.commands["build"].params.extend(additional_parameters)

src/pytask_parallel/config.py

@@ -21,6 +21,9 @@ def pytask_parse_config(config: dict[str, Any]) -> None:
     """Parse the configuration."""
     __tracebackhide__ = True
 
+    if config["n_workers"] == "auto":
+        config["n_workers"] = max(os.cpu_count() - 1, 1)
+
     try:
         config["parallel_backend"] = ParallelBackend(config["parallel_backend"])
     except ValueError:
@@ -30,13 +33,6 @@ def pytask_parse_config(config: dict[str, Any]) -> None:
         )
         raise ValueError(msg) from None
 
-    if config["n_workers"] == "auto":
-        config["n_workers"] = max(os.cpu_count() - 1, 1)
-
-    # If more than one worker is used, and no backend is set, use loky.
-    if config["n_workers"] > 1 and config["parallel_backend"] == ParallelBackend.NONE:
-        config["parallel_backend"] = ParallelBackend.LOKY
-
     config["delay"] = 0.1