You can try this, which will
- Filter out the unwanted item (
grep -v), and then - returns the first column, which contains the container id
Run this command:
docker rm $(docker ps -a | grep -v "my_docker" | awk 'NR>1 {print $1}')
To use cut instead of awk, try this:
docker rm $(docker ps -a | grep -v "my_docker" | cut -d ' ' -f1)
Examples for awk/cut usage here: bash: shortest way to get n-th column of output