26 Sep 2022
In order to run my Python scripts from other places than VS Code (eg Streamdeck action, Hazel, Alfred, etc..) I cannot run the scripts as single lines command (eg python3 <url>) because they require their own virtual environments to be activated Managing Virtual Environments in Python
So there is a missing link, which I think shell scripts are for.
Shell scripts are text files or small computer programs that consist of a collection of UNIX commands. You use a shell script to execute commands that you would normally type on the command line. However, rather than inputting them one by one into a Mac’s terminal, you can use shell scripts to execute the said group of commands with just one single action.
For my needs:
create file
create a file in Atom, starting with #! /bin/zsh (Zsh being the shell in macOS Monterey, differs by system/preference), with .sh (shell) extension.
Each line is a terminal command line, like I would enter manually, eg:
#! /bin/zsh
source /Users/xxx/Python/transcribee/venv/bin/activate
python3 /Users/xxx/Python/transcribee/test.py
run script
Single terminal command:
zsh <path_to_sh_file>
use variable
define as VAR= and call with $VAR.
ex.:
CURRENTDATETIME=`date +"%Y-%m-%d %T"`
used as:
$CURRENTDATETIME
insert breakline
echo -e "Hellow\\nWorld"
The option -e causes the newline character to be interpreted.
open URL
open opens files and URLs in the default or specified application.
open https://stackoverflow.com
or with Safari:
open -a Safari https://stackoverflow.com
for Chrome:
open -a /Applications/Google\ Chrome.app https://stackoverflow.com
note the backslash \ to escape white spaces in paths.
displaying a notification if background shell script encounters an issue
13 Dec 2022
I'm running a lot of Python scripts these days using shell scripts.
One issue is that when one of the Python scripts within the shell scripts fails, the shell script continues to run, and I don't get any notification.
Example would be my static sites where the Python generator might fail, but the Github push proceeds anyway without the site being updated:
#! /bin/zsh
source /path/to/project/venv/bin/activate
python3 /path/to/project/generate_btobsales.py
cd /path/to/github/folder/
git add .
CURRENTDATETIME=`date +"%Y-%m-%d %T"`
git commit -m $CURRENTDATETIME
git push origin main
open -a /Applications/Google\ Chrome.app https://github.com/my_project
Solution seems to be as follows:
- adding
set -eto return an error if any command fails. - adding
trap 'zenity --error --text="The Python script failed"' ERRto display a notification if an error is returned.
like:
#! /bin/zsh
set -e
source /path/to/project/venv/bin/activate
python3 /path/to/project/generate_btobsales.py
trap 'zenity --error --text="The Python script failed"' ERR
cd /path/to/github/folder/
git add .
CURRENTDATETIME=`date +"%Y-%m-%d %T"`
git commit -m $CURRENTDATETIME
git push origin main
open -a /Applications/Google\ Chrome.app https://github.com/my_project
However zenity is not installed on my Mac.
Needs to be installed with brew as brew install zenity.
Not working though.
TODO come back to this later.
Managing errors
16 Mar 2023
One issue has been that running shell scripts in the background does not raise any error if any of the Python scripts fail.
Workaround:
Append as follows in script python myscript.py 2>&1 | mailx -s "Script Error" youremail@example.com
#!/bin/bash
# Set the script name variable
SCRIPT_NAME="myscript.py"
# Run the script and send any errors via email
python "$SCRIPT_NAME" 2>&1 | mailx -s "Error in $SCRIPT_NAME" youremail@example.com