To run an executable/script, use `./pants run
` on a [`pex_binary
`](🔗) target. (See [package](🔗) for more on the `pex_binary
` target.)
or
To pass arguments to the script/executable, use `--
` at the end of the command, like this:
You may only run one target at a time.
The program will have access to the same environment used by the parent `./pants
` process, so you can set environment variables in the external environment, e.g. `FOO=bar ./pants run project/app.py
`. (Pants will auto-set some values like `$PATH
`).
Tip: check the return code
Pants will propagate the return code from the underlying executable. Run `
echo $?
` after the Pants run to see the return code.
Issues finding files?
Run `
./pants dependencies --transitive path/to/binary.py
` to ensure that all the files you need are showing up, including for any [assets](🔗) you intend to use.
## Watching the filesystem
If the app that you are running is long lived and safe to restart (including web apps like Django and Flask or other types of servers/services), you can set `restartable=True
` on your `pex_binary
` target to indicate this to Pants. The `run
` goal will then automatically restart the app when its input files change!
On the other hand, if your app is short lived (like a script) and you'd like to re-run it when files change but never interrupt an ongoing run, consider using `./pants --loop run
` instead. See [Goals](🔗) for more information on `--loop
`.
## Debugging
Tip: Using the IntelliJ/PyCharm remote debugger
First, add the following target in some BUILD file (e.g., the one containing your other 3rd-party dependencies):
You can check this into your repo, for convenience.
Now, use the remote debugger as usual:
Start a Python remote debugging session in PyCharm, say on port 5000.
Add the following code at the point where you want execution to pause and connect to the debugger:
Run your executable with `
./pants run
` as usual.Note: The first time you do so you may see some extra dependency resolution work, as `
pydevd-pycharm
` has now been added to the binary's dependencies, via inference. If you have dependency inference turned off in your repo, you will have to manually add a temporary explicit dependency in your binary target on the `pydevd-pycharm
` target.