Lazy solution to reinstall your Python libraries inside your PEW virtualenv wrapper or plain virtualenv

venv_upgrade.sh

#!/bin/sh
# THIS SCRIPT IS INTENDED FOR ROLLING RELEASE DISTRO USERS.
# Sometimes my local libraries didn't work after upgrading my Python, so I decided to write this helper script.
#
# Usage:
#    venv_upgrade [options]
#
# Options:
#    -h, --help            Show this help message.
#    -p, --path            Path to your virtualenv.
#    -n, --name            Name of your virtualenv (PEW ONLY).
#    -l, --list            List all virtual environments (PEW ONLY).
#        --dry-run         Run without actually upgrading your virtualenv.
#
# Some libraries may be not compatible to your new Python version. Be sure to add --dry-run to check it.
# This script can also be sourced from your favorite shell as long as it POSIX compatible (bash, zsh, etc.).

venv_upgrade() {
    usage() {
        printf "Usage: \n"
        printf "   venv_upgrade [options]\n\n\n"
        printf "Options:\n"
        printf "   -h, --help\t\t Show this help message.\n"
        printf "   -p, --path\t\t Path to your virtualenv.\n"
        printf "   -n, --name\t\t Name of your virtualenv (PEW ONLY).\n"
        printf "   -l, --list\t\t List all virtual environments (PEW ONLY).\n"
        printf "       --dry-run\t Run without actually upgrading your virtualenv.\n\n\n"
    }

    if ! command -v pip >/dev/null 2>&1; then
        printf "pip is not installed"
        return 1
    fi

    if ! command -v virtualenv >/dev/null 2>&1; then
        printf "virtualenv is not installed"
        return 1
    fi

    VENV_DRY_RUN=0

    while [ $# -gt 0 ]; do
        case "${1}" in
        -h | --help)
            usage
            shift
            return 0
            ;;
        -p | --path)
            VENV_DIR_PATH="${2}"
            VENV_ENV_NAME=$(basename "${VENV_DIR_PATH}")
            if [ ! -d "${VENV_DIR_PATH}" ]; then
                printf "Path does not exist"
                return 1
            fi
            shift
            shift
            ;;
        -n | --name)
            VENV_ENV_NAME="${2}"
            if ! command -V pew >/dev/null 2>&1; then
                printf "pew is not installed"
                return 1
            fi

            VENV_DIR_PATH=$(python -m pew dir "${VENV_ENV_NAME}")
            VENV_RETVAL=$?
            if [ $VENV_RETVAL -ne 0 ]; then
                return $VENV_RETVAL
            fi

            shift
            shift
            ;;
        -l | --list)
            if ! command -V pew >/dev/null 2>&1; then
                printf "pew is not installed"
                return 1
            fi

            python -m pew ls
            return 0
            ;;
        --dry-run)
            printf "\nDry run mode.\n"
            VENV_DRY_RUN=1
            shift
            ;;

        \
            *)
            shift
            ;;

        esac
    done

    if [ -z "${VENV_DIR_PATH}" ] || [ -z "${VENV_ENV_NAME}" ]; then
        usage
        return 1
    fi

    VENV_LIB_PATH="${VENV_DIR_PATH}/lib"

    VENV_PYTHON_VERSION=$(python -V | awk 'BEGIN{FS=OFS="."} NF--' | sed 's/\s//g' | tr '[:upper:]' '[:lower:]')
    VENV_DETECTED_PYTHON_RUNTIMES=$(find "${VENV_LIB_PATH}" -maxdepth 1 ! -path "${VENV_LIB_PATH}" -type d -name "python*" -printf '%f\n' | sort -k1)
    VENV_DETECTED_PYTHON_RUNTIMES_COUNT=$(echo "${VENV_DETECTED_PYTHON_RUNTIMES}" | wc -l)
    if [ "${VENV_DETECTED_PYTHON_RUNTIMES_COUNT}" -gt 1 ]; then
        printf "%d Python runtimes detected: \nPlease specify the one you want to upgrade to: (default 1) \n" "${VENV_DETECTED_PYTHON_RUNTIMES_COUNT}"
        VENV_IDX=1
        for VENV_PY in ${VENV_DETECTED_PYTHON_RUNTIMES}; do
            printf "\t%s. %s\n" "${VENV_IDX}" "${VENV_PY}"
            VENV_IDX=$((VENV_IDX + 1))
        done
        read -r "VENV_RESPONSE"
        while true; do
            case "${VENV_RESPONSE}" in
            *[!0-9]* | '') ;;

            *)
                if [ "${VENV_RESPONSE}" -gt 0 ] && [ "${VENV_RESPONSE}" -le "${VENV_DETECTED_PYTHON_RUNTIMES_COUNT}" ]; then
                    VENV_PYTHONLIB_VERSION=$(echo "${VENV_DETECTED_PYTHON_RUNTIMES}" | awk "NR==${VENV_RESPONSE}")
                    break
                fi
                ;;
            esac

            printf "Please enter a valid number between 1 and %d\n" "${VENV_DETECTED_PYTHON_RUNTIMES_COUNT}"
            read -r "VENV_RESPONSE"
        done
    else
        VENV_PYTHONLIB_VERSION="${VENV_DETECTED_PYTHON_RUNTIMES}"
    fi

    printf "Upgrading python runtime from %s to %s on %s\n" "${VENV_PYTHONLIB_VERSION}" "${VENV_PYTHON_VERSION}" "${VENV_ENV_NAME}"

    if [ "${VENV_PYTHON_VERSION}" = "${VENV_PYTHONLIB_VERSION}" ]; then
        printf "(%s) runtime is detected in your virtual environment. Do you want to recreate the virtual environment instead? [y/N]\n" "${VENV_PYTHONLIB_VERSION}"
        read -r "VENV_RESPONSE"
        case "$VENV_RESPONSE" in
        y | Y) ;;

        \
            *)
            printf "Upgrade cancelled. \n"
            return 0
            ;;
        esac
    fi

    VENV_SITE_PACKAGE_PATH="${VENV_LIB_PATH}/${VENV_PYTHONLIB_VERSION}/site-packages"

    VENV_PACKAGES=$(python -m pip freeze --path "${VENV_SITE_PACKAGE_PATH}")

    if [ -z "${VENV_PACKAGES}" ]; then
        printf "No packages found in %s. Aborting.. \n" "${VENV_SITE_PACKAGE_PATH}"
        return 1
    else
        printf "Packages to be installed: \n\n\n%s \n\nContinue? [y/N]?\n" "${VENV_PACKAGES}"
        read -r "VENV_RESPONSE"

        case "$VENV_RESPONSE" in
        y | Y)
            printf "Installing..\n"
            vENV_TMP_DIR=$(mktemp -d -t venv_upgrade.XXXXXXXXXX)
            VENV_TMP_REQUIREMENTS=$(mktemp -t venv_upgrade.requirements.XXXXXXXXXX.txt)
            printf "%s" "${VENV_PACKAGES}" >"${VENV_TMP_REQUIREMENTS}"

            if [ "${VENV_DRY_RUN}" -eq 0 ]; then

                mv "${VENV_DIR_PATH}" "${vENV_TMP_DIR}"
                virtualenv "${VENV_DIR_PATH}"
                VENV_CMD_INSTALL="${VENV_DIR_PATH}/bin/python -m pip install -r ${VENV_TMP_REQUIREMENTS}"
                eval "${VENV_CMD_INSTALL}"
                printf "\n\n\nYour packages were installed in %s. \n" "${VENV_DIR_PATH}"
                printf "Your old virtual environment moved to %s temporary folder. \n" "${vENV_TMP_DIR}"
                printf "If you want to restore the old virtual environment, run mv %s %s \n" "${vENV_TMP_DIR}" "${VENV_DIR_PATH}"

            else
                printf "Dry run enabled. Trying to install your packages in %s (temporary folder) then delete it.\n" "${vENV_TMP_DIR}"
                virtualenv "${vENV_TMP_DIR}"
                VENV_CMD_INSTALL="${vENV_TMP_DIR}/bin/python -m pip install -r ${VENV_TMP_REQUIREMENTS}"
                eval "${VENV_CMD_INSTALL}"
                printf "Cleanup: rm -rf %s \n" "${vENV_TMP_DIR}"
                rm -rf "${vENV_TMP_DIR}"
            fi

            printf "Cleanup tmp requirements file. \n"
            rm "${VENV_TMP_REQUIREMENTS}"
            ;;
        *)
            printf "Upgrade cancelled. \n"
            return 0
            ;;
        esac

        return 0
    fi

}

return 2>/dev/null || venv_upgrade "$@"