Virtual Environment

Quick reference

• 00:05 Okay, in this video we're going to set up a virtual environment.
• 00:08 And a virtual environment is a Python coding thing.
• 00:11 Anytime you want to create Python code, you want to set up a Python project,
• 00:15 it's a good idea to set up a virtual environment.
• 00:17 And a virtual environment is sort of like a little walled garden inside of your
• 00:21 computer.
• 00:22 And inside of our virtual environment, we can install different libraries,
• 00:26 different modules, different tools, and
• 00:29 it will sort of keep those things separate from the rest of our computer.
• 00:33 So it's a good idea when you're writing Python code to do that for
• 00:36 a lot of different reasons.
• 00:37 So, one of the main reasons is version control.
• 00:40 From time to time, there are different versions of the tools that you're going to
• 00:44 use in your project that come out.
• 00:46 For instance, Python may have a different version of Python in the future.
• 00:49 If you need to use a specific version of a specific thing,
• 00:52 it's much easier to do that inside of a virtual environment.
• 00:56 And so that's one of the big reasons why we do it.
• 00:58 Another reason is, it contains all of the stuff inside of the virtual environment,
• 01:02 and it sort of keeps it separate from the rest of the computer.
• 01:05 So if we mess something up, it's messed up inside of the virtual environment and
• 01:09 it's contained in there.
• 01:10 And it doesn't sort of spread to the rest of the computer.
• 01:12 So, it's just a good idea to set up a virtual environment whenever you're doing
• 01:16 any sort of Python coding is just really best practices.
• 01:19 So that's what we're going to do in this video and it's really easy to do so.
• 01:22 So I've opened up the Git Bash terminal.
• 01:23 If you don't remember, head over to your Windows start menu and
• 01:27 just type in Git and the Git Bash icon will pop up, just go ahead and
• 01:30 click that and this should appear.
• 01:32 So, you notice at the top, it says codemy@codemy,
• 01:35 that's my Windows login name, so yours is going to be different.
• 01:39 This MINGW64, that's just the Git Bash prompt.
• 01:43 So you can just sort of ignore that.
• 01:45 And right here, this little dollar sign, this is the terminal prompt.
• 01:50 This is where we can type in our commands.
• 01:52 So, the first thing we want to do is create a directory on our computer where
• 01:55 we're going to hold all of our project files.
• 01:57 So, to do that we can type in mkdir stands for make directory, and
• 02:02 I want to put this in the C drive.
• 02:04 And let's put this in a folder called python-excel, okay?
• 02:11 Now, if you are on Mac or Linux obviously there is no C drive so you can just create
• 02:15 it directly anywhere on your computer where you're comfortable putting it.
• 02:18 And the command is the same, mkdir and then name it whatever you want.
• 02:25 So, okay so now we want to move into that directory.
• 02:28 So we do that with the cd command, stands for change directly, and
• 02:33 we just type in that directory we just created so c/python-excel.
• 02:40 Okay, and you'll notice right here, it says we're in that directory.
• 02:43 So now we can type in the ls command if we want to list the stuff that's in this
• 02:47 directory.
• 02:48 And you'll notice there's nothing in there because we just created this directory,
• 02:50 there's nothing in there yet.
• 02:51 So, in the next video we'll go ahead and create our first Python file, but for
• 02:55 now we can just leave it blank.
• 02:58 So now, we want to create our virtual environment.
• 03:01 And to do that we're going to use something called venv, v-e-n-v.
• 03:04 And that just stands for a virtual environment.
• 03:07 And it comes with Python already, so we don't have to actually install it,
• 03:11 we just need to use it.
• 03:12 So to use it, type in python -m, and then venv, and
• 03:16 then let's name our virtual environment.
• 03:20 And I'm going to call ours virt, short for virtual.
• 03:23 So you can name it anything you want, but I suggest you just call it virt.
• 03:27 And go ahead and click Enter, and
• 03:28 this will take a couple of seconds in order to spin up the virtual environment.
• 03:33 And boom, now it's installed.
• 03:35 So we've installed virtual environment, now we need to turn it on.
• 03:38 And now if we type in the ls command to list the stuff in this directory,
• 03:42 you'll notice now there's this virt directory that we just created.
• 03:46 And it's called virt because right here, we called it virt.
• 03:50 If we were to type bob right there, it would be bob right there.
• 03:54 So, virt is the name of it.
• 03:56 So, all of our virtual environment files are located there.
• 04:00 So now we want to turn on our virtual environment,
• 04:05 and to do that we type in source virt/Scripts/activate.
• 04:14 And when we do,
• 04:15 you'll notice now above our terminal prompt is this virt in parenthesis.
• 04:20 And that's what allows us to know our virtue environment has been turned on.
• 04:24 So congratulations if you see this little virt thing on here,
• 04:26 it means you've created and installed and turned on your virtual environment, and
• 04:30 you're good to go.
• 04:31 If you're on a Mac or Linux, this command may not work in which
• 04:37 case try source of bin/activate I think is the Mac command or
• 04:42 /bin/activate, one of those two should work for Mac or Linux.
• 04:48 But for Windows users, it's just source virt/Scripts/activate.
• 04:52 So all right, let's go ahead and clear the screen.
• 04:55 And you'll notice again that virt is still there.
• 04:58 So if you want to turn off your virtual environment,
• 05:01 you can just type in deactivate.
• 05:03 And you'll notice now this little virt is gone above our terminal prompt, so
• 05:07 that means it's been turned off.
• 05:09 So I'm going to press the Up arrow key a few times to cycle through the last
• 05:13 few commands we typed.
• 05:15 So we don't have to re-type this again until I get to this source
• 05:18 virt/Scripts/activate command.
• 05:20 And now I'm just going to hit Enter to turn our virtual environment back on.
• 05:24 And we're ready to go.
• 05:25 So that's all for this video, in the next video, we'll go ahead and
• 05:30 create our first Python program.

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