[issue35328] Set a environment variable for venv prompt

[Baptiste Darthenay]

New submission from Baptiste Darthenay <baptiste.darthenay at gmail.com>:

When creating a new virtual env with `python3 -m venv .venv --prompt env`, the prompt information is only used to set a temporary PS1.

This information is lost when using custom prompt, for example with ZSH.

I propose to set VIRTUAL_ENV_PROMPT=__VENV_PROMPT__ when activating the newly created venv, to be used by tools and other shells.

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messages: 330533
nosy: batisteo
priority: normal
severity: normal
status: open
title: Set a environment variable for venv prompt
versions: Python 3.7, Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue35328>
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