Backup virtualenv before a Python 3.x upgrade and restore / recreate after the upgrade

backup_venv.sh

#!/bin/bash
cd ~
pip freeze --user --exclude-editable > REQUIREMENTS.txt

cd $WORKON_HOME  # or wherever you store your virtualenvs

for activate in ./*/bin/activate
do
  source $activate
  echo $VIRTUAL_ENV
  pip freeze --local --exclude-editable > $VIRTUAL_ENV/REQUIREMENTS.txt
  deactivate
done

clean_venv.sh

#!/bin/bash
OLD_PYTHON=python3.6
cd ~
rm -r .local/lib/$OLD_PYTHON

cd $WORKON_HOME
rm -r $(find -name $OLD_PYTHON -type d)

recreate_venv.sh

#!/bin/bash
cd ~
# rm .local/lib/python3.6
pip install --user -r REQUIREMENTS.txt

cd $WORKON_HOME
PYTHON_VERSION=$(python -c 'import sysconfig; print("python" + sysconfig.get_python_version())')
# New directory
export WORKON_HOME="./../$PYTHON_VERSION"
mkdir -p $WORKON_HOME

for VIRTUAL_ENV in ./*
do
  # Detect which python was used
  if [[ -d $VIRTUAL_ENV/lib_pypy ]]; then
    PY="pypy3"
  else
    PY=$(basename `ls $VIRTUAL_ENV/lib` | awk -F. '{print $1}')
  fi

  echo "Recreate $VIRTUAL_ENV using $PY in $WORKON_HOME"
  if [[ -f $VIRTUAL_ENV/.project ]]; then
    PROJECT=$(cat $VIRTUAL_ENV/.project)
    pew new -p $PY -r $VIRTUAL_ENV/REQUIREMENTS.txt -a $PROJECT $VIRTUAL_ENV
  else
    pew new -p $PY -r $VIRTUAL_ENV/REQUIREMENTS.txt $VIRTUAL_ENV
  fi
done

restore_venv.sh

cd $WORKON_HOME
for venv in *
do
  pew restore $venv
done

pip-restore-any(){
  # Installs any version
  # Run `pew toggleglobalsitepackages` if wheels are not available
  pip install $(cat $VIRTUAL_ENV/REQUIREMENTS.txt | awk -F"==" '{printf $1" " }')
}

pip-restore-exact(){
  # Installs exact version
  pip install -r $VIRTUAL_ENV/REQUIREMENTS.txt
}