python - `poetry run black myscript.py` 和 `black myscript.py` 有什么区别？

Question

基于poetry docs :

Likewise if you have command line tools such as pytest or black youcan run them using poetry run pytest

建议的使用方式black是:

poetry run black myscript.py

但是，如果我只是使用，我没有发现任何行为上的差异

black myscript.py

这两种方法有什么区别？

Answer 1

它允许您运行安装在虚拟环境中的 black(或 run 之后的任何命令)无需先激活您的虚拟环境.

相关说明在poetry run docs (强调我的):

The run command executes the given command inside the project’s virtualenv.

假设您有一个带有ma​​in.py 的poetry-demo 项目，并且您安装了black:

poetry-demo$ ls
README.rst     main.py        poetry.lock    poetry_demo    pyproject.toml tests

poetry-demo$ poetry add black
The following packages are already present in the pyproject.toml and will be skipped:

  • black

...

如果您没有首先激活您的虚拟环境(即 poetry shell)并且如果您没有在系统的其他任何地方安装 black，简单地执行 black file.py 会失败:

poetry-demo$ which black

poetry-demo$ black main.py
-bash: black: command not found

但是，使用poetry run，即使不激活您的虚拟环境，您也可以运行black:

poetry-demo$ poetry run black main.py
All done! ✨ 🍰 ✨
1 file left unchanged.

你困惑的根源可能是因为你已经激活了你的虚拟环境，所以真的没有区别:

poetry-demo$ poetry shell
Spawning shell within /path/to/virtualenvs/poetry-demo-hCA44HQ0-py3.8
poetry-demo$ . /path/to/virtualenvs/poetry-demo-hCA44HQ0-py3.8/bin/activate

(poetry-demo-hCA44HQ0-py3.8) poetry-demo$ black main.py
All done! ✨ 🍰 ✨
1 file left unchanged.

(poetry-demo-hCA44HQ0-py3.8) poetry-demo$ poetry run black main.py
All done! ✨ 🍰 ✨
1 file left unchanged.