I have a Python script that needs to be run from within a specific Anaconda environment (which I’ll call environment_name) for reasons that aren’t relevant here. It was tricky to get this working, so I figured it was worth a post. Here’s what made this challenging:

• The script only works if it’s actually run in a specific environment (accessed by executing conda activate environment_name), it’s not enough to set the python path in the shebang¹
• I want to be able to run the script when I’m not in that environment, or even when I’m not using Anaconda at all (which is usually the case)
• Activating an Anaconda environment in any shell script requires extra steps

The solution I landed on is to replace the typical shebang line with a block of code that looks like this:

#! /bin/sh -
':' '''Describe the script here--this script just prints the Python version'
eval "$(conda shell.bash hook)"
conda activate environment_name
exec python3 -- "$0" "$@"
'''

import sys
print("Hello from Python", sys.version)

This approach is not without weaknesses:

• It (probably?) requires that /bin/sh be bash (or maybe just bash-like?), which is not always the case; you might need to replace /bin/sh with the full path to bash
• The script may need to be run as a specific user, I haven’t checked
• The code looks ugly and interferes with code-highlighting
• It’s certainly fragile in other ways I’ve yet to find

I’m sharing it anyway because it did solve my problem, and I hope to save somebody else the time it took me to figure this out. Or better yet, be told the “right” way to do this from a Python/Anaconda expert.