[python] Add autoflake to auto rm unused import (#8897)

* Add a new commit hook to pre-commit, to auto
  remove unused imports
* Remove all unused pass statements
* Add autoflake to tox and out CI

close: #8592

dolphinscheduler-python/pydolphinscheduler/.pre-commit-config.yaml

@@ -45,3 +45,12 @@ repos:
             --config, 
             dolphinscheduler-python/pydolphinscheduler/.flake8
         ]
+  - repo: https://github.com/pycqa/autoflake
+    rev: v1.4
+    hooks:
+      - id: autoflake
+        args: [
+            --remove-all-unused-imports,
+            --ignore-init-module-imports,
+            --in-place
+        ]

dolphinscheduler-python/pydolphinscheduler/DEVELOP.md

@@ -104,6 +104,10 @@ tox -e local-ci
 It will take a while when you run it the first time, because it has to install dependencies and make some prepare,
 and the next time you run it will be faster.
 
+If you failed section `lint` when you run command `tox -e local-ci`, you could try to run command `tox -e auto-lint`
+which we provider fix as many lints as possible. When I finish, you could run command `tox -e local-ci` to see
+whether the linter pass or not, you have to fix it by yourself if linter still fail. 
+
 ### Manually
 
 #### Code Style

dolphinscheduler-python/pydolphinscheduler/setup.py

@@ -65,6 +65,7 @@ style = [
     "flake8-docstrings>=1.6",
     "flake8-black>=0.2",
     "isort>=5.10",
+    "autoflake>=1.4",
 ]
 
 dev = style + test + doc + build
@@ -95,11 +96,9 @@ class CleanCommand(Command):
 
     def initialize_options(self) -> None:
         """Set default values for options."""
-        pass
 
     def finalize_options(self) -> None:
         """Set final values for options."""
-        pass
 
     def run(self) -> None:
         """Run and remove temporary files."""

dolphinscheduler-python/pydolphinscheduler/src/pydolphinscheduler/exceptions.py

@@ -21,26 +21,18 @@
 class PyDSBaseException(Exception):
     """Base exception for pydolphinscheduler."""
 
-    pass
-
 
 class PyDSParamException(PyDSBaseException):
     """Exception for pydolphinscheduler parameter verify error."""
 
-    pass
-
 
 class PyDSTaskNoFoundException(PyDSBaseException):
     """Exception for pydolphinscheduler workflow task no found error."""
 
-    pass
-
 
 class PyDSJavaGatewayException(PyDSBaseException):
     """Exception for pydolphinscheduler Java gateway error."""
 
-    pass
-
 
 class PyDSProcessDefinitionNotAssignException(PyDSBaseException):
     """Exception for pydolphinscheduler process definition not assign error."""
@@ -48,5 +40,3 @@ class PyDSProcessDefinitionNotAssignException(PyDSBaseException):
 
 class PyDSConfException(PyDSBaseException):
     """Exception for pydolphinscheduler configuration error."""
-
-    pass

dolphinscheduler-python/pydolphinscheduler/tox.ini

@@ -16,17 +16,25 @@
 # under the License.
 
 [tox]
-envlist = local-ci, lint, doc-build-test, code-test, py{36,37,38,39}
+envlist = local-ci, auto-lint, lint, doc-build-test, code-test, py{36,37,38,39}
 
 [testenv]
 whitelist_externals = make
 
+[testenv:auto-lint]
+extras = style
+commands =
+    python -m isort .
+    python -m black .
+    python -m autoflake --in-place --remove-all-unused-imports --ignore-init-module-imports --recursive .
+
 [testenv:lint]
 extras = style
 commands =
     python -m isort --check .
     python -m black --check .
     python -m flake8
+    python -m autoflake --remove-all-unused-imports --ignore-init-module-imports --check --recursive .
     
 [testenv:code-test]
 extras = test