[Python-checkins] [3.8] [doc] Document VIRTUAL_ENV environment variable (GH-21970) (GH-24363)

[vsajip]

https://github.com/python/cpython/commit/6900a515c8410795f9a8ef2ad38740847a919b6d
commit: 6900a515c8410795f9a8ef2ad38740847a919b6d
branch: 3.8
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: vsajip <vinay_sajip at yahoo.co.uk>
date: 2021-03-01T15:07:31Z
summary:

[3.8] [doc] Document VIRTUAL_ENV environment variable (GH-21970) (GH-24363)

(cherry picked from commit 3584d4b64a5373440f78237eac734831cfd83f79)

files:
M Doc/using/venv-create.inc

diff --git a/Doc/using/venv-create.inc b/Doc/using/venv-create.inc
index c81aaf15d885a..b4089e61fa7b3 100644
--- a/Doc/using/venv-create.inc
+++ b/Doc/using/venv-create.inc
@@ -121,6 +121,10 @@ directory containing the virtual environment):
 |             | PowerShell      | PS C:\\> <venv>\\Scripts\\Activate.ps1  |
 +-------------+-----------------+-----------------------------------------+
 
+When a virtual environment is active, the :envvar:`VIRTUAL_ENV` environment
+variable is set to the path of the virtual environment. This can be used to
+check if one is running inside a virtual environment.
+
 You don't specifically *need* to activate an environment; activation just
 prepends the virtual environment's binary directory to your path, so that
 "python" invokes the virtual environment's Python interpreter and you can run