Determining the script path

[jberkel]

I'm using a Python dependency that itself uses python-dotenv. dot-env has some logic to determine the calling script path, to construct a search path for .env files. Obviously, running it from pex is a different situation. Is there an easy way to obtain the path of the "outer pex" from "inside the pex"?

[jsirois]

You can read the PEX environment variable.

[jsirois]

@jberkel for example:

:; cat <<EOF > exe.py
import os

from dotenv import load_dotenv


load_dotenv(dotenv_path=os.path.join(os.path.dirname(os.environ["PEX"]), ".env"))
print("OK?:", os.environ.get("OK"))
EOF

:; pex python-dotenv --exe exe.py -o example.pex 

:; ./example.pex 
OK?: None

:; echo OK=42 > .env

:; ./example.pex 
OK?: 42

[jberkel]

That's great! I might contact the dot-env maintainers to see if they can handle the PEX case inside the library itself.

[jsirois]

@jberkel I'd say no if I were them, but you may get lucky. One thing I can offer is for --scie {eager,lazy} a new --scie-load-dotenv. The underlying scie-jump technology already supports loading .env files regardless of the contents of the scie (Python app, Java app, etc.).

See:

• https://github.com/a-scie/jump/blob/main/docs/packaging.md#optional-fields
• https://science.scie.app/_/manifest/lift.html#load-dotenv

[jsirois]

The --scie-load-dotenv idea is implemented in #3046 and released in https://github.com/pex-tool/pex/releases/tag/v2.75.0.