Virtualenvwrapper postactivate and predeactivate (python)

.env

ENVVAR1=value
ENVVAR2="value 2"
#COMMENTED="Lines starting with hash will be skipped."

README.md

postactivate and predeactivate for Virtualenvwrapper

• The contents of postactivate and predeactivate go into their respective placeholders in $WORKON_HOME
• The .env file should be formatted as shown and placed in the top directory of your environment, e.g.
  $WORKON_HOME/my_environment

Then after workon my_environment the new environment variables will be set, and after deactivate the old ones will be restored.

postactivate

#!/bin/bash
# Populates environment variables in a .env file in the virtual env directory,
# proactively saving old variables with the same name to _OLD__$varname

if [ -f $VIRTUAL_ENV/.env ]
then
    for line in `sed '/^#.*/d' $VIRTUAL_ENV/.env`
    do
      varname="$(cut -d'=' -f1 <<<$line)"
      echo " setting envvar $varname"
      if `env | grep -q $varname`
      then
        export _OLD__$varname=${!varname}
      fi
      export $line
    done
fi

predeactivate

#!/bin/bash
# Unsets environment variables in a .env file in the virtual env directory,
# restoring saved variables from _OLD__$varname

if [ -f $VIRTUAL_ENV/.env ]
then
    for line in `sed '/^#.*/d' $VIRTUAL_ENV/.env`
    do
      varname="$(cut -d'=' -f1 <<<$line)"
      oldvarname="_OLD__$varname"
      if `env | grep -q $oldvarname`
      then
        echo "removing envvar $oldvarname and resetting $varname"
        export $varname=${!oldvarname}
        unset $oldvarname
      else
        echo "removing envvar $varname"
        unset $varname
      fi
    done
fi