Python 3.3 includes in its standard library the new package venv
. What does it do, and how does it differ from all the other packages that match the regex (py)?(v|virtual|pip)?env
?
This is my personal recommendation for beginners: start by learning virtualenv
and pip
, tools which work with both Python 2 and 3 and in a variety of situations, and pick up other tools once you start needing them.
Now on to answer the question: what is the difference between these similarly named things: venv, virtualenv, etc?
PyPI packages not in the standard library:
virtualenv
is a very popular tool that creates isolated Python environments for Python libraries. If you're not familiar with this tool, I highly recommend learning it, as it is a very useful tool.It works by installing a bunch of files in a directory (eg:
env/
), and then modifying thePATH
environment variable to prefix it with a custombin
directory (eg:env/bin/
). An exact copy of thepython
orpython3
binary is placed in this directory, but Python is programmed to look for libraries relative to its path first, in the environment directory. It's not part of Python's standard library, but is officially blessed by the PyPA (Python Packaging Authority). Once activated, you can install packages in the virtual environment usingpip
.pyenv
is used to isolate Python versions. For example, you may want to test your code against Python 2.7, 3.6, 3.7 and 3.8, so you'll need a way to switch between them. Once activated, it prefixes thePATH
environment variable with~/.pyenv/shims
, where there are special files matching the Python commands (python
,pip
). These are not copies of the Python-shipped commands; they are special scripts that decide on the fly which version of Python to run based on thePYENV_VERSION
environment variable, or the.python-version
file, or the~/.pyenv/version
file.pyenv
also makes the process of downloading and installing multiple Python versions easier, using the commandpyenv install
.pyenv-virtualenv
is a plugin forpyenv
by the same author aspyenv
, to allow you to usepyenv
andvirtualenv
at the same time conveniently. However, if you're using Python 3.3 or later,pyenv-virtualenv
will try to runpython -m venv
if it is available, instead ofvirtualenv
. You can usevirtualenv
andpyenv
together withoutpyenv-virtualenv
, if you don't want the convenience features.virtualenvwrapper
is a set of extensions tovirtualenv
(see docs). It gives you commands likemkvirtualenv
,lssitepackages
, and especiallyworkon
for switching between differentvirtualenv
directories. This tool is especially useful if you want multiplevirtualenv
directories.pyenv-virtualenvwrapper
is a plugin forpyenv
by the same author aspyenv
, to conveniently integratevirtualenvwrapper
intopyenv
.pipenv
aims to combinePipfile
,pip
andvirtualenv
into one command on the command-line. Thevirtualenv
directory typically gets placed in~/.local/share/virtualenvs/XXX
, withXXX
being a hash of the path of the project directory. This is different fromvirtualenv
, where the directory is typically in the current working directory.pipenv
is meant to be used when developing Python applications (as opposed to libraries). There are alternatives topipenv
, such aspoetry
, which I won't list here since this question is only about the packages that are similarly named.
Standard library:
pyvenv
(not to be confused withpyenv
in the previous section) is a script shipped with Python 3.3 to 3.7. It was removed from Python 3.8 as it had problems (not to mention the confusing name). Runningpython3 -m venv
has exactly the same effect aspyvenv
.venv
is a package shipped with Python 3, which you can run usingpython3 -m venv
(although for some reason some distros separate it out into a separate distro package, such aspython3-venv
on Ubuntu/Debian). It serves the same purpose asvirtualenv
, but only has a subset of its features (see a comparison here).virtualenv
continues to be more popular thanvenv
, especially since the former supports both Python 2 and 3.
venv
actually solve that problem? –
Lowering pip
vs. pipx
vs. poetry
vs. setuptools
... etc. –
Mcgarry venv
module. In the case of duplicating your python environment, you can use a slim python docker image and install all dependencies globally. The startup is a bit more involved for simply running a script but at least python and the dependencies are encapsulated. This is also good for reproducibility etc. –
Base some\path\python.exe myapp.py
and it automatically picks everything up without any activation magic. I don't like venv, it's also voodoo. Having a clean installation with the required packages is much eaiser to use than relying on yet another environment framework. –
Commissionaire I would just avoid the use of virtualenv
after Python3.3+ and instead use the standard shipped library venv
. To create a new virtual environment you would type:
$ python3 -m venv <MYVENV>
virtualenv
tries to copy the Python binary into the virtual environment's bin directory. However it does not update library file links embedded into that binary, so if you build Python from source into a non-system directory with relative path names, the Python binary breaks. Since this is how you make a copy distributable Python, it is a big flaw. BTW to inspect embedded library file links on OS X, use otool
. For example from within your virtual environment, type:
$ otool -L bin/python
python:
@executable_path/../Python (compatibility version 3.4.0, current version 3.4.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1238.0.0)
Consequently I would avoid virtualenvwrapper
and pipenv
. pyvenv
is deprecated. pyenv
seems to be used often where virtualenv
is used but I would stay away from it also since I think venv
also does what pyenv
is built for.
venv
creates virtual environments in the shell that are fresh and sandboxed, with user-installable libraries, and it's multi-python safe.
Fresh: because virtual environments only start with the standard libraries that ship with python, you have to install any other libraries all over again with pip install
while the virtual environment is active.
Sandboxed: because none of these new library installs are visible outside the virtual environment, so you can delete the whole environment and start again without worrying about impacting your base python install.
User-installable libraries: because the virtual environment's target folder is created without sudo
in some directory you already own, so you won't need sudo
permissions to install libraries into it.
multi-python safe: because when virtual environments activate, the shell only sees the python version (3.4, 3.5 etc.) that was used to build that virtual environment.
pyenv
is similar to venv
in that it lets you manage multiple python environments. However with pyenv
you can't conveniently rollback library installs to some start state and you will likely need admin
privileges at some point to update libraries. So I think it is also best to use venv
.
In the last couple of years I have found many problems in build systems (emacs packages, python standalone application builders, installers...) that ultimately come down to issues with virtualenv
. I think python will be a better platform when we eliminate this additional option and only use venv
.
EDIT: Tweet of the BDFL,
I use venv (in the stdlib) and a bunch of shell aliases to quickly switch.
— Guido van Rossum (@gvanrossum) October 22, 2020
pyenv
still has it's place under the sun despite venv
getting traction for virtual environments. The classic reason I can think of still using pyenv
right now in my workflows is that highest Python runtime that AWS Lambda supports is 3.8 and Python 3.9 being out I want other non-Lambda projects to be 3.9 based. So I still need pyenv
to switch between versions. Using pyenv-virtualenv
allows users to use both pyenv
and venv
(not `virtualenv) together. –
Mcgarry virtualenvwrapper
? –
Haemolysin $ path/to/python3x -m venv <MYVENVx>
or $ path/to/python3y -m venv <MYVENVy>
then when you activate the environment you will activate the python that was used to create the environment –
Yoshi UPDATE 2020-08-25:
Added below "Conclusion" paragraph
I've went down the pipenv
rabbit hole (it's a deep and dark hole indeed...) and since the last answer is over 2 years ago, felt it was useful to update the discussion with the latest developments on the Python virtual envelopes topic I've found.
DISCLAIMER:
This answer is NOT about continuing the raging debate about the merits of pipenv versus venv as envelope solutions- I make no endorsement of either. It's about PyPA endorsing conflicting standards and how future development of virtualenv promises to negate making an either/or choice between them at all. I focused on these two tools precisely because they are the anointed ones by PyPA.
venv
As the OP notes, venv is a tool for virtualizing environments. NOT a third party solution, but native tool. PyPA endorses venv for creating VIRTUAL ENVELOPES: "Changed in version 3.5: The use of venv is now recommended for creating virtual environments".
pipenv
pipenv- like venv - can be used to create virtual envelopes but additionally rolls-in package management and vulnerability checking functionality. Instead of using requirements.txt
, pipenv
delivers package management via Pipfile. As PyPA endorses pipenv for PACKAGE MANAGEMENT, that would seem to imply pipfile
is to supplant requirements.txt
.
HOWEVER: pipenv uses virtualenv as its tool for creating virtual envelopes, NOT venv which is endorsed by PyPA as the go-to tool for creating virtual envelopes.
Conflicting Standards:
So if settling on a virtual envelope solution wasn't difficult enough, we now have PyPA endorsing two different tools which use different virtual envelope solutions. The raging Github debate on venv vs virtualenv which highlights this conflict can be found here.
Conflict Resolution:
The Github debate referenced in above link has steered virtualenv development in the direction of accommodating venv in future releases:
prefer built-in venv: if the target python has venv we'll create the environment using that (and then perform subsequent operations on that to facilitate other guarantees we offer)
Conclusion:
So it looks like there will be some future convergence between the two rival virtual envelope solutions, but as of now pipenv- which uses virtualenv
- varies materially from venv
.
Given the problems pipenv solves and the fact that PyPA has given its blessing, it appears to have a bright future. And if virtualenv delivers on its proposed development objectives, choosing a virtual envelope solution should no longer be a case of either pipenv OR venv.
Update 2020-08-25:
An oft repeated criticism of Pipenv I saw when producing this analysis was that it was not actively maintained. Indeed, what's the point of using a solution whose future could be seen questionable due to lack of continuous development? After a dry spell of about 18 months, Pipenv is once again being actively developed. Indeed, large and material updates have since been released.
pyenv
is not an alternative to virtualenv
. And neither of those things are alternatives to pipenv
. They do different things. Just like Django, Python and PostgreSQL are different things. –
Norward Let's start with the problems these tools want to solve:
use case | solution |
---|---|
My system package manager don't have the Python versions I wanted or I want to install multiple Python versions side by side, Python 3.9.0 and Python 3.9.1, Python 3.5.3, etc | Then use pyenv. |
I want to install and run multiple applications with different, conflicting dependencies. | Then use virtualenv or venv. These are almost completely interchangeable, the difference being that virtualenv supports older python versions and has a few more minor unique features, while venv is in the standard library. |
I'm developing an /application/ and need to manage my dependencies, and manage the dependency resolution of the dependencies of my project. | Then use pipenv or poetry. |
I'm developing a /library/ or a /package/ and want to specify the dependencies that my library users need to install | Then use setuptools. |
I used virtualenv, but I don't like virtualenv folders being scattered around various project folders. I want a centralised management of the environments and some simple project management | Then use virtualenvwrapper. Variant: pyenv-virtualenvwrapper if you also use pyenv. |
Not recommended
I'm developing an /application/ and need to manage my dependencies, and manage the dependency resolution of the dependencies of my project. Then use pipenv or poetry.
> is this something similar to requirements
file? What use case/problem would one use venv
and pipenv
together? –
Whittington HOWEVER: pipenv uses virtualenv as its tool for creating virtual envelopes, NOT venv which is endorsed by PyPA as the go-to tool for creating virtual envelopes.
from @Canaan made me understand i should not use pipenv since venv is the recommended one. Am i wrong? meaning, it is better to use pyenv
(for python version management) + venv
+ requirements.txt
for a python application. –
Whittington virtualenvwrapper
does not seem to be very actively maintained. The latest release on PyPi currently is from early 2019, compatibility is listed for up to Python 3.6 and commits to the source repository are very infrequent. –
Slapdash virtualenvwrapper
and pyenv-virtualenvwrapper
a try. As far as I can see without doing extensive testing, despite the lack of recent updates they indeed both seem to work with Python 3.10.8. –
Slapdash Jan 2020 Update
@Flimm has explained all the differences very well. Generally, we want to know the difference between all tools because we want to decide what's best for us. So, the next question would be: which one to use? I suggest you choose one of the two official ways to manage virtual environments:
- Python Packaging now recommends Pipenv
- Python.org now recommends venv
pipenv
and venv
aren't alternatives to each other, just like Django and Python aren't alternatives to each other. With venv
alone, you can't install packages, for instance, whereas pipenv
does offer a mechanism to install packages. –
Norward python -m venv foo; source foo/bin/activate; pip install numpy
. Both venv
and pip
are available out of the box. The comment sounds a little misleading. –
Boru venv
with pip
in your example or vice-versa. You can't dovenv install numpy
, and you can't do pip foo ; source foo/bin/activate
. So I stand by my comment that they are not alternatives to each other. Also, venv
and pip
are not available out of the box, say on an Ubuntu installation (even though python3
is available out of the box). On Ubuntu, you would have to install python3-venv
(using APT) to get venv
, and separately you would have to install python3-pip
to get pip
. –
Norward - pyenv - manages different python versions,
- all others - create virtual environment (which has isolated python version and installed "requirements"),
pipenv want combine all, in addition to previous it installs "requirements" (into the active virtual environment or create its own if none is active)
So maybe you will be happy with pipenv only.
But I use: pyenv + pyenv-virtualenvwrapper, + pipenv (pipenv for installing requirements only).
In Debian:
apt install libffi-dev
install pyenv based on https://www.tecmint.com/pyenv-install-and-manage-multiple-python-versions-in-linux/, but..
.. but instead of pyenv-virtualenv install pyenv-virtualenvwrapper (which can be standalone library or pyenv plugin, here the 2nd option):
$ pyenv install 3.9.0 $ git clone https://github.com/pyenv/pyenv-virtualenvwrapper.git $(pyenv root)/plugins/pyenv-virtualenvwrapper # inside ~/.bashrc add: # export $VIRTUALENVWRAPPER_PYTHON="/usr/bin/python3" $ source ~/.bashrc $ pyenv virtualenvwrapper
Then create virtual environments for your projects (workingdir must exist):
pyenv local 3.9.0 # to prevent 'interpreter not found' in mkvirtualenv
python -m pip install --upgrade pip setuptools wheel
mkvirtualenv <venvname> -p python3.9 -a <workingdir>
and switch between projects:
workon <venvname>
python -m pip install --upgrade pip setuptools wheel pipenv
Inside a project I have the file requirements.txt, without fixing the versions inside (if some version limitation is not neccessary). You have 2 possible tools to install them into the current virtual environment: pip-tools or pipenv. Lets say you will use pipenv:
pipenv install -r requirements.txt
this will create Pipfile and Pipfile.lock files, fixed versions are in the 2nd one. If you want reinstall somewhere exactly same versions then (Pipfile.lock must be present):
pipenv install
Remember that Pipfile.lock is related to some Python version and need to be recreated if you use a different one.
As you see I write requirements.txt. This has some problems: You must remove a removed package from Pipfile too. So writing Pipfile directly is probably better.
So you can see I use pipenv very poorly. Maybe if you will use it well, it can replace everything?
EDIT 2021.01: I have changed my stack to: pyenv + pyenv-virtualenvwrapper + poetry
. Ie. I use no apt or pip installation of virtualenv or virtualenvwrapper, and instead I install pyenv
's plugin pyenv-virtualenvwrapper
. This is easier way.
Poetry
is great for me:
poetry add <package> # install single package
poetry remove <package>
poetry install # if you remove poetry.lock poetry will re-calculate versions
pyenv + pyenv-virtualenvwrapper + poetry
, especially how you instruct poetry
to use a specifique version installed via pyenv
, and if you are disabling create virtual environment in poetry
? –
Hoehne As a Python newcomer this question frustrated me endlessly and confused me for months. Which virtual environment and package manager(s) should I invest in learning when I know that I will be using it for years to come?
The best article answering this vexing question is https://jakevdp.github.io/blog/2016/08/25/conda-myths-and-misconceptions/ by Jake Vanderplas. Although a few years old, it provides practical answers and the history of Python package and virtual environment managers from the trenches as these state-of-the-art was developing.
It was particularly frustrating for me in the data science and "big data cloud computing" communities, because conda is widely used as a virtual environment manager and full function package manager for Python and JavaScript, SQL, Java, HTML5, and Jupyter Notebooks.
So why use pip at all, when conda does everything that pip and venv variants do?
The answer is, "because you MUST use pip if a conda package is simply not available." Many times a required package is only available in pip format and there is no easy solution but to use pip. You can learn to use conda build
but if you are not the package maintainer, then you must convince the package owner to generate a conda package for each new release (or do it yourself.)
These pip-based packages differ along many important and practical dimensions:
- stability
- maturity
- complexity
- active support (versus dying or dead)
- levels of adoption near the Python ecosystem "core" versus "on the fringes" (i.e., integrated into Python.org distro)
- easy to figure out and use (for beginners)
I will answer your question for two packages from dimension of package maturity and stability.
venv and virtualenv are the most mature, stability, and community support. From the online documentation you can see that virtualenv is in version 20.x as of today. virtualenv
virtualenv is a tool to create isolated Python environments. Since Python 3.3, a subset of it has been integrated into the standard library under the venv module. The venv module does not offer all features of this library, to name just a few more prominent:
is slower (by not having the app-data seed method), is not as extendable, cannot create virtual environments for arbitrarily installed python versions (and automatically discover these), is not upgrade-able via pip, does not have as rich programmatic API (describe virtual environments without creating them).
virtualenvwrapper is set of scripts to help people use virtualenv (it is a "wrapper" that not well-maintained, its last update was in 2019. virtualenvwrapper
My recommendation is to avoid ALL pip virtual environments whenever possible. Use conda instead. Conda provides a unified approach. It is maintained by teams of professional open source developers and has a reputable company providing funding and a commercially supported version. The teams that maintain pip, venv, virtualenv, pipenv, and many other pip variants have limited resources by comparison. The pip virtual environment plurality is frustrating for beginners. The pip-based virtual environment tools complexity, fragmentation, fringe and unsupported packages, and wildly inconsistent support drove me to use conda. For data science work, my recommendation is that to use a pip-based virtual environment manager as a last resort when conda packages do not exist.
The differences between the venv variants still scare me because my time is limited to learn new packages. pipenv, venv, pyvenv, pyenv, virtualenv, virtualenvwrapper, poetry, and others have dozens of differences and complexities that take days to understand. I hate going down a path and find support for a package goes belly-up when a maintainer resigns (or gets too busy to maintain it). I just need to get my job done.
In the spirit of being helpful, here are a few links to help you dive in over your head, but not get lost in Dante's Inferno (re: pip).
A Guide to Python’s Virtual Environments
Choosing "core" Python packages to invest in for your career (long-term), versus getting a job done short term) is important. However, it is a business analysis question. Are you trying to simply get a task done, or a professional software engineer who builds scalable performant systems that require the least amount of maintenance effort over time? IMHO, conda will take you to the latter place more easily than dealing with pip-plurality problems. conda is still missing 1-step pip-package migration tools that make this a moot question. If we could simply convert pip packages into conda packages then pypi.org and conda-forge could be merged. Pip is necessary because conda packages are not (yet) universal. Many Python programmers are either too lazy to create conda packages, or they only program in Python and don't need conda's language-agnostic / multi-lingual support.
conda has been a god-send for me, because it supports cloud software engineering and data science's need for multilingual support of JavaScript, SQL, and Jupyter Notebook extensions, and conda plays well within Docker and other cloud-native environments. I encourage you to learn and master conda, which will enable you to side-step many complex questions that pip-based tools may never answer.
Keep it simple! I need one package that does 90% of what I need and guidance and workarounds for the 10% remaining edge cases.
Check out the articles linked herein to learn more about pip-based virtual environments.
I hope this is helpful to the original poster and gives pip and conda aficionados some things to think about.
Pip is necessary because conda packages are not (yet) universal. Many Python programmers are either too lazy to create conda packages, or they only program in Python and don't need conda's language-agnostic / multi-lingual support.
--- if so - then isn't this making a strong hint why not to use conda? Or if conda wants to be universal, then there should be a clear time soon enough for that. So despite the many pip/virtualenv flavors then maybe better pick a winner and cancel all the rest than pick conda ... (is virtualenv[wrapper] already the winner?) –
Coleville pip
, venv
etc. I haven't had these tools actually annoy me in years of use. –
Igal I want to add docker
into this list, as well as conda
that several answer already mentioned.
conda is heavier than the virtual environments the title mentioned. It also give isolation on some system-python tools, such as ffmpeg or gpu drivers.
docker is even better, it gives you a whole new OS to play with. With a good Dockerfile and a docker build
, docker run
script, you have good documentation of how your environment is built, and it is easy to populate, migrate to other environment (staging, production, cloud). It helps you in the long run.
Another thing: PyCharm provides several options to select your virtual environment. It helps the new-comers not to worry about this thing. Recommend to use it before you know what the virtual environment is.
© 2022 - 2024 — McMap. All rights reserved.
virtualenv
andpyenv
do not perform the same function, and are not alternatives to each other. See my answer. – Norwardvenv
, which is the correct tool to use going forward for Python 3. It should really be first on the list, followed byvirtualenv
. docs.python.org/3/library/venv.html – Legitimateconda
(Miniconda). Its better than all the solutions listed here and makes them all obselete. As a bonus, it works with more than just Python, you can install a wide variety of software with it, not just Python packages. It includes an installation ofpip
so all yourpip install
's will continue to work as normal. Withconda
you can install an entire app software stack such as specific versions of Django, Gunicorn, Celery, PostgreSQL, RabbitMQ, nginx, Java, R, etc. all at the same time. – Boninapip-tools
added to this guide. – Negotiate