Installing Python Packages with pip and virtualenv / venv

When you install Python packages globally there can be only one version of a Python library across all of your programs. This means you'll quickly run into version conflicts.

The solution to these problems is separating your Python environments with so-called virtual environments. They allow you to separate Python dependencies by project, including selecting between different versions of the Python interpreter.

A Virtual Environment (or "virtualenv", "venv" for short) is an isolated Python environment. Physically, it lives inside a folder containing all the packages and other dependencies, like native-code libraries and the interpreter runtime, that a Python project needs.

To demonstrate how virtual environments work as a "sandbox" I'll give you a quick walkthrough where we'll set up a new environment (or virtualenv, as they're called for short) and then install a third-party package into it using the Python pip command.

To get more Python Tricks and to discover the full potential of Python check out "Python Tricks: The Book" at the link below:

* * *

FREE Python Tutorials & News:

[KarlSchmidtDev]

I've had a hard time finding good guides for virtual environments in Python - this is a great tutorial. Thanks!

[jaylansiquot]

Slowly getting through all of these, been programming in python for the last 4 months and these tips are really making python feel more fluid to me. Thanks again Dan.

[muneshj]

I was searching this topic from past 3 hours and finally ended up here, thanks man it worked.

[marekcarlisle]

exceptionally helpful, thank you for the concise explanation of venvs, and how to use them

[amaterasu]

This is the topic I was wondering how to do. You really hit the nail for my thirst for Python knowledge. Thank you! :D

[yusupovjasur]

Thank you so much, man! So helpful tutorial!

[ianmonat]

I created a virtual environment and cloned a python project, call it Project A. Do I need to activate the virtual environment every time I run the .py in Project A, to ensure that that project's dependencies don't affect Project B's dependencies? Or is just activiating the virtual environment the first time, when initially cloning Project A, sufficient?

[antoniogallardo]

hey i been having an issue with my virtualenv. i always get "Error: name 'cmd' not defined" any advise on how i can fix this?

[alwinsebastian]

does the "which" command works with windows too ??

[DrBenVincent]

to what extent is this the same or different from using coda virtualenv's rather than pip? Same basic logic but simply different commands?

[musingbox]

how do you install a virtualenv ? and where, using sudo or ---user ?

[tanzeelarubab]

I am getting error. Modules are not installed in venv using the commands

[kimacable]

the tree command in your tutorial did not work for me. A little googling showed its not a shell command. It has to be downloaded and installed using pip install tree or brew install tree. It then worked fine regardless of the shell used.

[vaibhavshah]

Hello Dan, When i try to install django in env that time I am getting this type of error ''Command "python setup.py egg_info" failed with error code 1 in so can you please help me out from this....

[TheAfreitag]

It would be great if you could do a video on how to modify and especially remove a venv. I have one that I'd either like to re purpose by renaming it. Or simply remove it and start fresh.

[qzorn]

nice info, now can opencv2.x be installed in env2 and opencv3.x in env3? thanks

[orjihvy]

how do we decide when to use Venv versus Conda?

[gilang]

How do I remove/delete a virtualenv? please help

[sunnz]

Hi Daniel, I have been using the virtualenv command, are they the same thing?

[Utshaw]

0:55 did you mean distribution package ?