pyenv-virtualenv/bin/pyenv-sh-activate

#!/usr/bin/env bash
#
# Summary: Activate virtual environment
#
# Usage: pyenv activate <virtualenv>
#        pyenv activate --unset
#
# Activate a Python virtualenv environment in current shell.
# This acts almost as same as `pyenv shell`, but this invokes the `activate`
# script in your shell.
#
# <virtualenv> should be a string matching a Python version known to pyenv.

set -e
[ -n "$PYENV_DEBUG" ] && set -x

# Provide pyenv completions
if [ "$1" = "--complete" ]; then
  echo --unset
  exec pyenv-virtualenvs --bare
fi

versions=("$@")
shell="$(basename "${PYENV_SHELL:-$SHELL}")"

if [ -z "$versions" ]; then
  OLDIFS="$IFS"
  IFS=: versions=($(pyenv-version-name))
  IFS="$OLDIFS"
fi

if [ "$1" = "--unset" ]; then
  echo "pyenv deactivate"
  exit
fi

if [ "${#versions[@]}" -gt 1 ]; then
  echo "pyenv-virtualenv: cannot activate multiple versions at once: ${versions[@]}" 1>&2
  exit 1
fi

pyenv-virtualenv-prefix "${versions}" 1>/dev/null

echo "pyenv shell \"${versions}\""
case "$shell" in
fish ) echo ". \"$(pyenv-prefix "${versions}")/bin/activate.fish\"" ;;
*    ) echo "source \"$(pyenv-prefix "${versions}")/bin/activate\"" ;;
esac