fix errors when `dp` is executed without any subcommands #6277

	on:
	push:
	branches-ignore:
	- "gh-readonly-queue/**"
	pull_request:
	merge_group:
	concurrency:
	group: ${{ github.workflow }}-${{ github.ref \|\| github.run_id }}
	cancel-in-progress: true
	name: Test Python
	jobs:
	testpython:
	name: Test Python
	runs-on: ubuntu-22.04
	strategy:
	matrix:
	include:
	- python: 3.8
	tf:
	torch:
	- python: "3.11"
	tf:
	torch:

	steps:
	- uses: actions/checkout@v4
	- uses: actions/setup-python@v5
	with:
	python-version: ${{ matrix.python }}
	cache: 'pip'
	- uses: mpi4py/setup-mpi@v1
	with:
	mpi: openmpi
	# https://github.com/pypa/pip/issues/11770
	- run: python -m pip install -U "pip>=21.3.1,!=23.0.0"
	- run: pip install -e .[cpu,test,torch]
	env:
	TENSORFLOW_VERSION: ${{ matrix.tf }}
	DP_BUILD_TESTING: 1
	- run: pip install horovod mpi4py
	env:
	HOROVOD_WITH_TENSORFLOW: 1
	HOROVOD_WITHOUT_PYTORCH: 1
	HOROVOD_WITHOUT_GLOO: 1
	- run: dp --version
	- run: pytest --cov=deepmd source/tests --durations=0
	env:
	NUM_WORKERS: 0
	- uses: codecov/codecov-action@v4
	env:
	CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
	pass:
	name: Pass testing Python
	needs: [testpython]
	runs-on: ubuntu-latest
	if: always()
	steps:
	- name: Decide whether the needed jobs succeeded or failed
	uses: re-actors/alls-green@release/v1
	with:
	jobs: ${{ toJSON(needs) }}

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