Generated files

Creating an environment writes files inside the destination folder and beside it. This page lists each one, what it holds, and how to suppress it.

Inside the environment folder

pyvenv.cfg

Marks the folder as a virtual environment and points the interpreter at the Python it was built from, per PEP 405. Deleting it breaks the environment.

home = /usr/local/python-3.14/bin
implementation = CPython
python-version = 3.14
version_info = 3.14.6.final.0
version = 3.14.6
executable = /usr/local/python-3.14/bin/python3.14
command = /usr/bin/python3 -m virtualenv /home/user/env
virtualenv = 21.7.6
include-system-site-packages = false
base-prefix = /usr/local/python-3.14
base-exec-prefix = /usr/local/python-3.14
base-executable = /usr/local/python-3.14/bin/python3.14

Three keys carry the version, and they differ in precision and in who should read them:

Key	Example	Read it when
python-version	3.14	You want the feature release, which is what selects a wheel tag or a type-checker target. PEP 838 defines it and every tool creating an environment must write it.
version	3.14.6	You need the patch level as well. PEP 838 discourages reading it in favor of python-version.
version_info	3.14.6.final.0	You need the release level and serial. Written by virtualenv rather than by any specification.

prompt appears as an extra key when you pass --prompt. The base-* keys come from the creator and vary by creation method.

CACHEDIR.TAG

Marks the environment as regenerable cache content, following the cache directory tagging specification, so backup tools skip it. virtualenv leaves an existing file untouched.

.gitignore

Holds *, keeping the environment out of Git. Skip it with --no-vcs-ignore. virtualenv leaves an existing file untouched, and writes nothing for Mercurial, Bazaar or Subversion, none of which honor ignore files in a subdirectory.

bin / Scripts

The interpreter, the console scripts of any seeded package, and the activation scripts for each shell. Environment layout lists the names the interpreter answers to, and Activators covers the shells.

Beside the environment folder

.venv

A PEP 832 redirect file holding the destination folder name, which tells editors and type checkers which environment of the parent folder to use. virtualenv writes it in a folder holding a pyproject.toml and no .venv yet. Force it with --venv-redirect, skip it with --no-venv-redirect.

Warning

This file is provisional because PEP 832 is still a draft, and virtualenv follows the PEP as it changes. A minor or patch release may change this file, --venv-redirect and --no-venv-redirect in backward incompatible ways.

py314

Format rules virtualenv follows when it writes the file:

Rule	Behavior
Encoding	UTF-8 without a byte order mark.
Content	One line: the destination folder name, relative to the parent folder, followed by a newline.
Target	The first environment created in a folder holding a pyproject.toml; with --venv-redirect, the environment created last, in any folder.
.venv folder	Left alone, whether folder or symlink; virtualenv writes nothing when the destination itself is .venv.
Existing redirect	Kept, unless you pass --venv-redirect and its target’s pyvenv.cfg carries the virtualenv key; one that another tool wrote, or that points at a missing folder, stays either way.
Failure	Logged as a warning; the environment is still created.