unzipping to arbitrary location within /tmp

[ws1088]

Because I need to read a datafile, I assume I have to use --not-zip-safe and therefore when I run my pex-ed file it will unzip to ~/.pex. Is there a way to instruct pex to unzip to a randomly generated directory within /tmp? i.e. I don't need to cache the unzipped wheels.

[jsirois]

First to your assumption: it's not correct; you don't actually need to use --not-zip-safe.
To access files uniformly between zipped sys.path entries and directory sys.path entries you only need to use either:

1. In the standard library: https://docs.python.org/3/library/pkgutil.html#pkgutil.get_data
2. In setuptools using pkg_resources resource_stream or resource_string: https://setuptools.readthedocs.io/en/latest/pkg_resources.html#basic-resource-access

If - for whatever reason - you do want to use the traditional file system APIs (open), you can control the unzip location via the PEX_ROOT environment variable, but that directory will not be automatically cleaned up; so you'd need some scripting around the execution of the PEX. For example:

#!/usr/bin/env bash

set -euo pipefail

export PEX_ROOT=$(mktemp -d)
trap "rm -rf ${PEX_ROOT}" EXIT
/path/to/my/pex "$@"

[jsirois]

If you need a more pointed example of how to access resources via pkgutil or pkg_resources after trying and failing to use them, let me know and I can whip that up. When possible, I'd recommend that approach. Only if 3rdparty code needs to access the data file and expects a filesystem path should you need to resort to --not-zip-safe.