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Python Virtual Environment Tutorial (Windows 10)
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Dec 11, 2024
How to create, and manage a Python virtual environment in Windows -- everything a new Python programmer needs to know. š Subscribe for more: https://bit.ly/3lLybeP š Follow along: https://analyzingalpha.com/blog/python-installation-windows-10 Virtual Environment Cheat Sheet - Create: python -m venv venv - Activate: venv\Scripts\activate.bat - Listing: pip list - Saving: pip freeze (greater than symbol) requirements.txt - Restoring: pip install -r requirements.txt - Deactivating: deactivate 0:00 Introduction 0:25 What Are Virtual Environments? 2:40 Virtual Environment Command Cheat Sheet 3:00 Check if Python is Installed with Version 3:22 Create a Virtual Environment 4:12 Activate Windows Virtual Environment 4:36 List Packages in Virtual Environment
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0:00
hello everyone today we're going to
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learn about python virtual environment
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specifically on a windows 10 machine
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so what are we covering well first we're
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going to take a step back and understand
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what a virtual environment is and why it
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matters then we're going to log into our
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windows machine and create operate and
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remove in a virtual environment
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essentially we're going to cover all the
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commands that you need to know as a new
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programmer to manage and maintain your
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virtual environment
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so what is a virtual environment well
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virtual environments enable you to
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manage multiple programs with different
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dependencies
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you know python includes this thing
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called pip which allows you to install
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and manage dependencies that are not
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part of the standard library now a
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dependency is any library or software
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that our program depends on right that's
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where it gets the word dependency
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depends on that are not part of the
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standard library and that really if it
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was part of the standard library we
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would need to download it because we
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already have it
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let's create you know give it make this
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more concrete let's say we're creating a
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project and we need to use the pandas
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library the pandas library is one of my
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favorite data science libraries
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um but all we need to do to install
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pandas is type pip space install
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base pandas and that will install pandas
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into our global environment
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now that enables all of the programs
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that we write to access this pandas
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library so we can use those you know
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pandas tools well that's you're saying
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well that's great leo right well it
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introduces a pretty immense problem
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see what i did there
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what happens if you have two projects
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that use different versions of the same
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software so let's say we download the
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pip install pandas but this time we
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specify a different version well that
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might break our original project right
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so the good news is you know virtual
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environments solve this challenge you
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know virtual environments or virtual m's
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for short
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create an environment that's isolated or
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encapsulated well encapsulated is just
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the fancy programmer term for saying
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it's a container right it's contained
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and isolated so all we install is
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only the exact software with the
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appropriate version in each
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for in each virtual environment for each
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project so each project has its own
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little bubble where it has everything
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that it needs that's what a virtual
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environment does and we can you know if
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we have a hundred projects we'd have a
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hundred different virtual environments
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right and that's you know now and we
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have confidence that all of our projects
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will run with the appropriate
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dependencies
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and the great news is as a python
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version 3.3 there's nothing additional
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we need to do because the virtual
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environments are built into the standard
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library
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so before we
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log into our windows machine here are
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the commands that we're going to be
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covering today feel free to take a
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screenshot of this or just feel free to
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you know follow along as i work through
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the commands on the windows machine
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okay now that we're logged into our
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windows machine the first thing we're
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going to want to do is check to see if
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python is installed we can do this by
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typing python-version
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and if you
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receive a version number not an error
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python is indeed installed
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so if you don't have python installed
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feel free to watch my previous video
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i'll link it on how to install python on
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the windows 10 machine
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so with python installed
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to create a virtual environment we
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simply type python-m for module v-e-n-v
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for virtual environment and then we can
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name our virtual environment anything
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with that we want you could say leo's
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v-e-n-v right
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that's a good name but a better name is
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actually v-e-n-v so why is v-e-n-v a
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better name well it's conventional for
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virtual environments to be named the env
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so we'll have
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our project folder and then within our
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project folder we have our virtual
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environment
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you know
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named venv
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and that's you know if we had 50 project
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folders they'd all be named venv
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okay we can type dir now when we see
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that our virtual environment is indeed
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in a folder within our project folder
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now we're not using our virtual
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environment yet the first thing that we
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need to do is activate our virtual
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environment we do that by typing v-e-n-v
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backslash scripts
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backslash activate.bat
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now when we hit enter we'll notice that
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the venv is pre-pended to our path
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this allows us or it's a visual
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indicator
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letting us know that
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our virtual environment is active now we
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can type all of our standard commands
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like pip list to see what are the
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packages that are in our virtual
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environment so right now we just have
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the scaffolding packages the packages
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that come with every virtual environment
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pip and setup tools
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and now let's install our
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you know that
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data science library we discussed
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previously panda so pip install pandas
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and this will install pandas numpy and
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everything you know that pandas you know
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all the dependencies for pandas
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so that way we can use pandas
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you know for any of our prod
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for our project
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okay
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and you'll notice when i type dir
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there's nothing different right
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everything
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about within everything is contained
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within the venv folder now that's
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something i want to bring up so virtual
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environments are made to be disposable
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right you should never put any of your
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project files into a virtual environment
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folder
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because we don't save virtual
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environments to our repository right so
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obviously you know whenever we're coding
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we're saving our files to you know
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github or git lab or you know any
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version control of your choice
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we don't want to commit this stuff to
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version control because they can get
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pretty big i mean you know we can
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install hundreds if not thousands of
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packages over time there's no reason to
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you know save you know that information
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all we really need to know
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are the packages or the dependencies and
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their version numbers right and with the
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packages and version numbers we can
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recreate the virtual environment so
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that's exactly what we're going to do
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now
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so we can type pip
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freeze
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and then we pipe that to requirements
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dot text
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and hit enter
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i'll type more
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requirements.text and you'll notice
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now we have the exact versions
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of the dependent and the dependencies
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with their exact versions listed in this
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requirement.txt file now this is the
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file that we would save to our
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you know
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repository and then if we you know
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move to a different computer or one of
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our colleagues needs to recreate this
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environment they can do so from the
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requirements
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that file so let's do that actually do
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that so we'll type deactivate
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to deactivate our virtual environment
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because if we delete the virtual
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environment and then we try to run
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pandas or python
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commands
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we're going to be trying to run python
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from a virtual environment that's
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deleted we'll get a bunch of errors so
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we'll type deactivate
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okay we can see that now we have
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our requirements text file
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and our virtual environment we can
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remove directory
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and then we'll denv for instance denv
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we'll say yes
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and then
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dir so now our virtual environment no
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longer exists now clear that screen to
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make things a little bit easier to read
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now
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how do we recreate our virtual
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environment simple we type
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python-m-v-e-n-v
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so we're using the virtual environment
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module v-e-n-v we'll name it v-e-n-v
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again
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right
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and now after the v-env is created we'll
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have to activate it because if we don't
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then we just we'd end up installing all
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of you know we'll send up installing
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pandas into our global environment which
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is not what we want to do so we type the
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env backslash scripts backslash activate
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that
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again now it lets us know that we're in
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our virtual environment and not our
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global environment
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now we do pip
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install dash r requirements dot text
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and we'll hit enter and you'll notice
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we're pulling the exact same packages
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that were installed previously
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so we've now successfully recreated our
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virtual environment
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and we can do pip
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list
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and notice that all of our packages
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are indeed
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uh indeed there now so that's it so this
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is these are the the essential commands
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that you need to know when you know
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managing a virtual environment you know
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how to create one you need to know how
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to activate it need to know how to
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export out the you know the dependencies
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with their versions using pip freeze and
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then you need to know how to deactivate
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it and that's pretty much it there are
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other commands but
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again 99 of the time is a new program
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this is exactly what you need to need to
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know so if you like this video please
9:13
give me a thumbs up and i wish you the
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best of luck on your python programming
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journey thanks everyone
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