>> On today's Visual Studio toolbox Tyrique is going to
show us how to get started with Python development
using Visual Studio Code. [MUSIC] >> Hi, welcome to
Visual Studio Toolbox. I'm your host Robert
Green and joining me today is Tyrique White. Hey Tyrique. >> Hi Robert, thanks for having me. >> Thanks for being on the show. >> Yeah, I'm Tyrique
White everyone and I'm a program manager for Python
developer tools here at Microsoft. >> Cool. So we're going to
talk about doing some Python, we're going to show
Visual Studio code. >> Right. >> That's awesome. So give us again the very brief because I
think we've talked about it before, but the very brief
sweet spot for Python. I is a C-sharp developer, or a JavaScript developer, when and why should I learn Python? What are the scenarios
that are most prevalent? >> Definitely. So Robert, excellent question when we
get a lot at conferences. The sweet spot for Python is
being able to build apps quickly. One of my demos later
I'm going to show in nine lines of code
I'm able to create. I'll be at a very
simple web application. I still create a web application. That's the basis for Python. It's the scrapping
language where people are able to prototype quickly. But it's also used for
production code as well, which is super exciting. >> Okay. >> Yeah, cool. >> Yeah, awesome. So today specifically we're going to
talk about Python and VS Code. For any of those who don't know, VS Code is this free
open-source cross-platform tool which uses a popularized extension
model for every language. >> Right. >> So today we're going to talk about the Python extension in VS Code
and getting started experience. Then later, my colleague
Jeffrey will be talking about data science and VS
Code for Python development. >> So that will be
another episode that we'll record after this one. >> Definitely. >> Showing people behind the scenes and how it works here in the studio. >> Right. >> This way I'm wearing
the same shirt. >> Awesome, cool. So let's get started. So the Python Extension offers a
lot of great jam-packed features. It offers Intellisense, debugging, testing their support for virtual environment
packages like VM and Conda, some formatters like
Black and Autopep8, as well as some popular
linters like pylints. Some fun facts about Python
extension in VS Code, it's the most popular extension
than the VS Code marketplace. >> Real, more certain than C-sharp. >> Yes. >> That's interesting. >> Even better is, Visual
Studio Code is now at the top three tool for
Python developers, which is really exciting. A lot of hype around Python and hopefully by the end of this you guys will understand
a bit more why. That's all. >> So it's an extension which
implies that you have to go get it? >> Yes, exactly. >> You install VS Code, you don't have this Python extension. >>Right. So yeah. Let's take a step back. Let's show you how to download
and install Visual Studio Code. So the link to get Visual Studio
Code if you don't have it is code.visualstudio.com and you come to this external and download page. As you can see it auto
detects which OS I'm using. >> Okay. >> I can quickly grab
a copy of VS Code. I already have it installed but
I'm sure we get the idea there. Once you have Visual Studio
Code you are going to open it, and you're going to see
this welcome screen. This welcome screen has tools
that allow you to customize. It has this wonderful activity
bar here which gives you access to all of your extensions
that you have installed. So after you download
Visual Studio Code and you want to use Python, you have to go get
the Python extension. >> Okay. >> So to do that you're going to
go to the Extensions batch here, and I'm going to type Python. Because it's the most popular, it's going to come up right
at the top and you're going to see the Python
extension for Microsoft. >> Not the Python for VS Code
or the Python extension? >> No. You want the one that has the Green star here. Good question. >> The one that you worked on. >> The one that I worked on. >> Not that there's anything
wrong with those other ones, but this is the one you worked on? >> Definitely. As you can see, I've already installed this. So it says uninstall which
I'm not going to do, but they'll be an install
badge that can be click on. You can also see that we have some quick tips here
on how to get started, kind of the things I'm
going to cover today. So you need to install VS
Code which you've done that. You need to install the
extension which I've done. Then the third thing you need is an installation of
Python on your machine. >> Right. >> Yeah. One misconception we find is that some
people often think that the Python extension
for VS Code it comes with Python and it
does not currently. So one way to get around that is
depending on which OS you're on. For Windows, we recommend
going to python.org which I have here to download the
latest release of Python, on Mac a brew install
works fine and for Linux, typically the bundled version of Python that comes with
the Linux works well, you get all of these features
of the Python extension. >> Got it. >> Sound good. >> All right. Awesome. >>So now we've got code, we got the extension, we got Python. >> We do, I have python. Perfect. Okay. So let's get started. Let's get people
accustomed to the UI here, because it is a bit
different to get on-boarded. >> Okay. >> So now that I have the extension. As you can see, I have
the File Explorer here. When I open a folder, I'm going to be able to see
the tree view of that folder, see all the dependencies and
all the files within there. I have a debugger icon which
we'll talk about later. I have a lot of other things. VS Code comes inbox
with source control. So I can use my favorite repos, connect to those, and do all
of that stuff I know and love. We also have the tool bar down here, which allows you to see. I'm signed into Azure currently. I have the life share
extension installed. I have my toolbar up here,
all that good stuff. >> Okay. >> So what I now want to do is create a folder and let's get started playing around some
code. How does that sound? >> Sounds great. >> Another cool thing is, by default when you install
VS Code on Windows, it adds VS Code to the path. I'll show you exactly
what that means. So what I want to do is I want to
navigate to my Command Prompt, and I'm going to find my Demos
folder that I have here. I'm going to create
a new folder for us. I'm going to call it VS toolbox. I'm going to navigate to that folder. Now what's really cool is, because I have VS Code on the
path on my Windows machine, all I have to do is type code. into the Command Prompt, and it will open up an instance
of VS Code inside of that folder. >> Okay. >> You can see that from
my File Explorer here. >> So you can open
the folder from code, you can go to the folder and
launch code from that location? >> Exactly. On Linux and Mac you have to run a command
to get VS Code on path, but it's super handy if
your command line focus. So now what I'm going to do
actually is create a new file. This is the important part of
activating the Python extension. In order for the
extension to activate, which you're seeing down there, activating extension, you need
to select a Python folder. Sorry, excuse me, a Python file. >> Okay. >>.Py is the file type. As you can see I'm immediately, to verify that
extension is activated, I actually have Python
down here in my toolbar. If I click on this, it
gives me the list of all the different interpreters I have installed on my machine for Python. >> Is it okay when
you installed Python? >> Well, I've installed
multiple different versions for different reasons; for testing, for a playing around. But these are all the
interpreter versions I have. As the extension can pick up
most of those if they are in the standard places which they typically are when
you install Python. So pretty cool stuff there. So we created our file. So now what I want to
do is I want to talk about the command palette. That's going to be super
helpful for us because for developers who are bit
more Command Line driven, you want to have that terminal
experience inside the editor. So in order to get to what
I call the Command Palette, you're going to do on a Windows
machine Control Shift P, to bring up the Command Palette. Again, the Command Palette
has all of the commands you could ever want
and love for Python. All those commands of Python
or denoted by Python colon. >> Okay. >> You can scroll
down the entire list to get anything that you want. I am after create terminal, because I want to pull up a terminal for some command line driven stuff that I'm
going to talk about now. >> Okay. >> Cool. So what's really cool here is that I can start editing
or start writing some code. So if I write print, you can see that immediately I'm
starting to get what we call intellisense as well
as some documentation. So let's say I wasn't familiar
with the print statement, I can scroll over to this
documentation tool tip here, and I can see exactly
what parameters it takes. For this I just want to
print "Hello world". >> Okay. >> Cool. To run this, this is actually something we've recently added a couple
of releases ago, is the green Run button. So I can actually
just run my code with this button and it prints out
in the terminal, "Hello World". >> Cool. >> Our classic example
for coding,"Hello world". >>All right. >>Perfect. That's cool. Now, the next thing I want
to talk about which is really important for
Python development is the concept of a
virtual environment. Are you familiar with
virtual environments router? >> Not that much, no. >> Okay. So I'll explain
briefly what those are. So in Python you can have
application A and B. Let's say I'm a developer, I'm working on two
different applications. However, each application requires separate versions of packages
in order to function correctly. >> Okay. >> If I were to include all of
those different package versions in the same single application
or same environment, there's a possibility that
I might have conflicts. Some code may not run, something may get broken. So typically what we recommend
for Python developers is to create a virtual environment which I'm going to show
you how to do now. Cool. So back to my
command line here. So I'm in my VS toolbox folder. I have my hello.Py file, print "Hello world", we're all good. So there are different commands
depending on the OS you're using. I'm actually going to show you
when we're on those command. Then also we can look at
the Linux, Mac command. But in order to run, to create a virtual environment
from the command line, what I want to do is
I want to type Py, short for Python -3 for the version
of Python I'm going to use. Dash m, which is saying, okay, I'm going to pass a module
that I want you to use. This module is called VM, short for virtual environment
which makes sense. I'm actually going to call
our virtual environments. Give me any name you want. What's
your favorite folder name? >> My favorite folder name, pictures. >> Pictures. Cool. >> What's really cool is you notice this pop-up that comes. It says. "We noticed a new virtual
environment has been created, do you want to select it
for the workspace folder?" What's really cool about
that is if I select "Yes" and navigate to
my.vscode folder here, you'll see that we include this line with a path to that pictures
virtual environment. So the next time I open this folder, I'll already be inside of this
virtual environment which you can see is being denoted here
pictures virtual environment, and so I can get more productive
more quickly the next time. >> That's not an actual folder
on the hard drive, right? >> So it creates a local
copy, actually good question. It creates a local copy of
Python for this workspace, and you can see the list of
scripts that this includes as well as all of the libraries that you may have in that
virtual environment. But again, it's just
local to this workspace, so that way your application
can get all of the stuff inside of that virtual
environment. So I actually. >> It sticks around, if
I exit code come back in I can have access to that environment or do
I have to recreate it? >> Exactly, you have
access to the environment. So what I'm actually going to do
now is "Hello world" is exciting, but I actually want to show you a web app that I have with the
virtual environment already create. >> Okay. Cool. >> So let's actually answer
your question right now. So in order to close this I'm
going to go to File, Close folder. There are a couple of ways
I can open a new folder. I can go to File, Open Folder here, and
navigate on my File Explorer. There's the Start Menu which
allows me to open folder, but actually the demo I want is "Sentimentapi"
and it's under my recent. So why not just click it there? Cool. So a couple of
things to immediately notice about this application, is it's a simple web
application using the popular Python package flask which is a weighted just create
simple web applications, and to answer your question Robert, I have a virtual environment
here called "vstoolbox". Again, I pre-created this so it
saved when I opened it back up. What's even better is that
I could actually activate that virtual environment inside
the terminal in two ways. So if your command line driven again the way in
which you're going to activate a virtual environment on a Windows machine is you can start with the
virtual environment name, so vstoolbox backslash
because we're on Windows, scripts backslash
activate and you'll see that the virtual
environment is activated by this parentheses with the
virtual environment name. >> So then does that information
store like in source control. So if I take this app, put it in GitHub, go home, clone it, and bring it down locally I have not only the code but also
the environment information? >> Yeah, absolutely. If you want to share the virtual environment with developers in your team or with friends you definitely can do that. I'll also show you or you can just create a new one,
but I'll show you. We've talked a little
bit about that but I think it'll come full
circle in a minute. Another quick way you can activate
this virtual environment, if you don't want to have to remember that path to the activate file, what you can do on a Windows
machine is control shift back tick. What it'll do is it'll open
a new terminal for you with this virtual environment
already activated. So some really cool stuff here. Let's explore the
editor for a minute. So you guys or everyone has probably noticed the yellow squiggles
that are appearing here. These yellow squiggles are
what we call linting messages, and so what's important to know is
that the first time you install the Python extension
it's going to ask if you want to install a linter. The default currently as Pylint, and so it is going to ask you
if you want to use Pylint, but we also support other
lenting tools like Flake8 etc. So what you're seeing here
are these linting messages. So if I hover over those linting
messages, it's telling me, it's saying, "Hey, I can't find
unresolved import text blob." So what that essentially
means, is that, it can't find this package inside
of my virtual environments. So it's giving me an
error which is super useful because it gives me a code diagnostic or a problem which I can also
view under problems here, and you see that I have
the list of problems, unresolved import Flask,
unresolved import textblob. So what we can do actually
is install those. One thing that's also
different about this folder compared to the last folder
we created, is that, I have this
requirements.txt file here, and for people who don't know for Python developers this
is just the list of all the dependencies that my application needs
to function properly. So back to your original point. Depending on the kind of setup
you prefer what source control, you may send up your virtual environments so people can download it
and just activate it or you might just send up the requirements.txt file
and allow people to first create a virtual environment and then install all the
packages thing here. So what I'm going to do
is I'm going to install those packages from this
requirements.txt file, so back to my command line notice
again that I'm still inside this virtual environment
because I want all these packages contains
locally to this application. So I'm going to go pip install -r and then requirements.txt
and hit "Enter". What you're going to
notice is you're going to notice that it's going to find those packages
and install them for me. It's getting the list, I've downloaded these
before so it's just using the cache
diversions of these guys. What's important to
note is that when it installs these you're
going to notice that these error messages are going to
go away, which is really cool. So while it's installing those packages let's explore
this application a bit. So what this is, as I said before, is
the simple Flask gap. So what I'm doing here is
I'm essentially creating a Flask gap that's contained
inside this folder called Startup. I have a simple homepage
here which is just saying, "Python loves vstoolbox," and this is actually a
really cool application because it's not only just a
simple web application but it's the sentimentapi is the
title of the folder denotes. So what this is going
to allow us to do, is it's going to allow us
to hit an end point with a Word and this API is
going to help us determine the sentiment of that
word because maybe I just need help determining what
kind of sentiment words have. So very cool it finished
installing the packages for us, and notice that my
problems went away, and suddenly if I hover over
Flask I get documentation for it. Text blob I Get-module text blob
which is really cool stuff. So now what I want us to do
we explore this application. So let's actually run
this application. There are couple of
ways you can run it. I want to run it using the debugger, because I also want to use
this as a moment to talk about debugging and kind
of what that gets you. As I stated previously, this is a sentiment API pretty simple only less
than perhaps 10 lines of code if you take out all
the comments and the spaces, and that's again the beauty of Python's your earlier point in
less than 20 lines of code, essentially, I can create
a powerful sentiment API. I have some to do
for myself actually, I need to actually build the API. So if I scroll down to line 13, this is actually the
routes that's creating that endpoint that
will allow us to send a word in and get the
sentiment back out. So what I want to do is how this module is working
is it's saying it's going to take in that message if the sentiment score is greater than
zero we're going to determine, we're going to say it's positive. It's less than zero its negative. So what I'm going to do is I'm
actually going to write that out. So if textblob I'm using that package and notice I'm
getting my IntelliSense here. So I'm going to tap to
accept that message. Again, is what I want. So if the message has a sentiment and notice that
again this IntelliSense with the documentation which is
allowing me to learn as I type.polarity is less than zero, then I'm going to
reassign that sentiment, I'm going to say,
"Okay your negative." Trying to type at the same time and let's get rid of my comment here. >> So how does text blob
have a sentiment property? >> Sorry? >> Textblob.sentiment. >> Oh, it's the beauty
of the textblob package. >> Really, it comes with
sentiment built-in? >> Yeah. >> That's cool. >> Which is another cool
thing about Python, I could very well
create my own sentiment API from scratch if I wanted
to, but why reinvent the wheel? >> Because I've never seen a text box that I've ever
used have that built into it. >> Right. So what it actually does
that passes in that message to the textblock module and then it does some stuff under the hood then
with cool sentiment polarity etc. >> Cool. >> So we reassign that
sentiment has negative, and then what I'm actually
going to do is I'm going to return that sentiment on the page, on the web application page
which you'll see in a second. So cool. Let's run the application. >> All right. >> I'm going to run it
using the debugger actually because there are a couple of
things I want to talk about. So let's set a breakpoint on line 15, notice that I clicked to the left of the line number
which is called the gutter. For those of you who
are used to debugging it's going to be the
same kind of feel, for those who aren't fear not it's super easy to get started
with the debugger. So to start this, there are
a couple of ways I can run my debugger and I'm going to just collapse that so I can
give you full attention here. I can use the toolbar, click "Debug" and click
"Start debugging." It also has the keyboard shortcut F5 and so what I'm going to do is
I'm going to start doing that. Notice that when I click
"Start debugging" it's going to present to debug
configuration menu. We have a list of popular templates that we
know Python developers use. Remember earlier I mentioned
that this is a Flask gap? >> Yeah. >> So you can see that Flask
is in that configuration list, and so that's what I wanted
and I'm going to select it. The next step for debugging a web app is entering the path
to my start-up file. Remember I said that
this start-up file is contained inside of a
folder called Startup, so what I actually want
to do is I want to tweak this path a little bit
to actually point to my start-up file that is creating my flask gap which is startup/app.py. Once I hit "Enter" it's
going to start debugging for me and notice that
this toolbar down here changes to orange to denote
that I'm in debugging mode. Another cool thing is that debug icon here becomes highlighted in white, so you can see that I'm
also debugging as well. >> I guess it did. >> It did, yeah. >> Okay. >> I've never noticed that. >> Yeah. It's a pretty
cool nifty thing. >> But at the same
time, do you remember, I never tend to notice
these things back, you remember the big controversy
over in Visual Studio the menu choices at the top are all caps and it was
a big controversy. >> That actually predates
my time in Microsoft. >> Anyway, I discovered that
because there was a controversy. >> No, yeah. >> Enough about me, let's
get back to the app. >> Yeah. So to debug a web app, another thing that people getting
started with web apps may not know is that in order to hit that break point that
I've sent on line 15, I actually need to navigate to
the URL that it's giving me here. >> Okay. >> So it tells me that
it's running on this URL, and what's really cool
is that inside VS code in order to get to that URL, I can either copy and paste
it into my browser of choice, or I can just control click, which I'm going to do. >> Oh, look at that. >> You can see it says
"Python loves VS toolbox". Notice that because I've set
this break point inside of the app.py that defines that message, I actually, in order to
hit that break point, I need to send a message to this API. So let's do it. What's
the phrase that you love or maybe want to know the
sentiment of, I don't know. >> Let's say "Champion". >> "Champion", let's see what
the sentiment of champion is. So notice that I have
this wheel spinning here. >> Because we are in the
middle of the World Series and either today or tomorrow there
will be a champion grounds. >> Oh, wow. Well let's see
what the sentiment is. So you can tell that VS Code, the icon here is blinking orange, which means that it
did something magical. What it's done is it's hit this
break point inside of our API. Let's explore the debug
menu for a minutes. So notice that it got
our message "Champion". This is our locals variable window. I can also have my watch window, I have my call stack, all of this good stuff, and I can also step through lines. So to step over, I could actually use the debug toolbar there
or I can just "F10", so I'm just going to use
the [inaudible] there. You notice that as I step, it's said "okay"
remember we say that we determined all sentiments
to be positive at first, and then we run them
through this if statement. So I'm just going to step over again. In order to continue, I can either hit the arrow here to continue and
run it all the way through, or I can just hit "F5". So I'm going to hit "Continue" again. If I navigate back to my API, I see that the word
"Champion" is positive. >> Nice. Yeah, pretty cool. >> All right, let's do another test. >> Let's do another test. >> Yes. Let's test a new message. >> Okay, let's test a new message. This time, I'm going to rerun this, but I'm going to try and
rerun it a different way, I'm still using the debugger
but a slightly different way. So this time, to run this application with the
break point set on line 15, I'm going to use my debug icon
that I mentioned earlier. Here's what's really cool about
this is that the debug icon gives me access to the configuration
menu that I saw before. So if I click this "drop-down"
and select "Add configuration", what it's going to do and then I have to hit the green "play" button, start debugging, it's
going to send me into that same debug configuration menu. >> Okay. >> You may be wondering, "Oh Tyrique, why do I have to type this again?", and it's because our configuration
last time wasn't saved, and so by going through these
steps we're going through now, we're saving that configuration and I'll prove that
to you in a second. So I'm going to navigate
to Flask again, put that path, and notice that it creates this
file called "launched.json". We find that this launch file is very scary or intimidating for people who are first
starting out with VS code, but fear not, it's simply an array. It's a JSON format, an array with a list of
different configurations. But notice that. >> Everything's saved. >> It saves, right, and my startup path is saved. I have some different arguments
here which are on by default, and to show you where it gets saved, if you navigate back to your file explorer by using
the explorer button here, the dot VS code folder, if there wasn't one created before, it'll be created for
you and you'll have that logic configuration saved. This is an important because, again, you don't have to go through the
startup steps again to save it. So let's go back to my
debugger, and you notice, see it says "this
time" instead of "AD configuration" or "no
configuration" like it said before, I get Python flask. Another important thing to
realize about debugging is that, notice that I'm currently inside
of the "launch.json" file. If I start the debugger
here it will actually throw an error because it thinks I'm
trying to debug this JSON. So in order to avoid that, I need to go back actually to the
file that I'm trying to debug. So we're going to hit
our green "play" button. Again, I need to navigate to. So let's try another word. >> All right. So this is
a test of the sentiment. So I'm from Boston. >> Okay. >> In Boston when we like
something like this, we'd say "It's wicked cool". >> "Wicked cool". >> Now "Wicked" has the sentiment of negative but "Cool" has
the sentiment of positive. So let's see what happens. >> Let's see how it's
Text bot handles it. So "Wicked cool". Okay. Notice again,
it's flashing orange, it means it hit the break point, and it's verified that
it hits the break point by the yellow line here. What's also really
cool is that all of the information you're getting
in the variables one here, you can actually hover
over variables here. >> Yeah. >> You get the tool tips
which it's not playing nice, there we go, it was shy
at first, but here we go. You can see all the
different properties. Again, to continue, I'm
going to press "F5". I'm going to navigate back to this. >> Excellent. >> It says "Wicked cool is positive". >> All right. Yes. >> It's pretty cool. >> Very good. >> Yes, it's very awesome. Again, to recap that, if you start debugging
from the toolbar here, you don't get that
configuration saved. So in actually to get that saved, to make you more
productive than next time, you want to use the debug icon
and then an add a configuration. >> Cool. >> Which is really really cool stuff. So let's recap a
little bit of what we talked about because I know
that we've covered a lot. So using virtual environments, which we talked about to help you manage packages for
different applications. So creating new environments, depending on if you're a Mac or Linux user or a Windows user,
the commands are there. >> Okay. >> You can then the command I use, that I didn't really touch on at the time but now
I'm going to as the pip install - r. requirements.txt, that's if your file or if your
project has one of those, you can create a virtual
environment first and then you can install the
requirements that are there. You can also install individual
module names if you want to. >> Okay. >> Getting started with debugging. Of course there are multiple
ways you can do this, but the way that I recommend, in the way that I like to do it, is actually using the
bug icon which takes me to the debug configuration menu
I can click that "Drop-down", hit "App configuration", I can choose my configuration
of what I want to debug. >> The second time you have to retype all of the actions
because you didn't save it, you're going to hit straight to here. >> Right, exactly. Put the path to that web application, and that "launch.json" gets created, and then remember, you don't want
to debug the "launch.json" file, you actually want to go back to the Python file that you are interested in and then
hit the green run button. >> Okay. >> Pretty cool stuff and that's about all I have
for you guys today. >> All right. >> Just talking about that
getting started experience. >> Cool. So for more information, people can go to aka.ms
/VST /pythonvscode. >> Yeah. >> There's a Getting
Started tutorial there. More information on Python
within Visual Studio Code. Where is a good place for people
to go to learn Python in general? >> There's a lot of
documentation online, our getting started tutorial, we'll teach you links
out to other things, other material that is useful, but yes, for example, if you want to learn about Flask, the Flask documentation that
they have is excellent. >> Okay. >> If you ever have any
questions about getting started though and you want to
interact directly with the team, our Twitter handle is
at Python VS code. >> Okay. >> All one word, and we are always interacting
with users trying to understand what experiences
work best and which don't. >> Fantastic. >> Yeah. Awesome.
Thanks for having me. >> Thanks for coming on.
Those are great introduction to not only Visual Studio code for folks that haven't been playing
around with it a lot but also how you get started using
Python and it's awesome. >> Perfect. Yes. >> Thanks. >> Awesome. Thank you. >> Hope you guys enjoyed
that and we will see you next time on Visual Studio Toolbox. [MUSIC]
