Django style migrations for alembic

makemigrations.sh

#!/usr/bin/env bash
# This script gives alembic django style migrations
# Revision id is auto-incremented and autogenerate is the default behavior

# Alter this line to point to migrations folder
NEXT_ID=`ls path/to/db/versions/* | grep -P '/\d{4}_.*\.py'|wc -l`
NAME=""
FLAG="--autogenerate"

function usage() {
    echo "
USAGE:
./makemigrations.sh migration_name [-e | --empty]
where:
    migration_name:   slug to name migration as
    -e | --empty:     create an empty migration (otherwise autogenerate from python)
"
}

while [ "$1" != "" ]; do
    case $1 in
         -e | --empty )
             FLAG=""
             ;;
         -h | --help )
             usage
             exit
             ;;
         * )
             if [ ! -z "$NAME" ]
             then
                 echo "Name option supplied more than once" >&2
                 usage >&2
                 exit 1
             else
                 NAME=$1
             fi
             ;;
    esac
    shift
done

alembic revision ${FLAG} -m "${NAME}" --rev-id=`printf "%04d" ${NEXT_ID}`