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So far, what we have done is all output.

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We printed the screen,
it's not very interactive, is it?

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The conversation's kind of one sided.

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Take a second and
think about applications that you use.

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Just about every one of them gathers
information from you, whether that be

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a field, or a check box, a button click,
or telling a bird when to flap its wings.

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Every application you make is going to
need to gather some information from its

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users, this is called input.

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And gathering input from users from the
command line is pretty straight forward,

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so let's get to it.

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So let's explore this input thing
a little bit in the Python shell first.

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So I'm gonna open that up,
we'll type python.

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Let's give ourselves
a little bit of space.

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All right, so the command to get input
from the user is super easy to remember,

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it's input.

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So input, that's a function,
so we're gonna call it.

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And inside here you put the prompt.

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So let's ask a question, so
let's say, How are you today?

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So see how the cursor is here,
it's waiting for me to type, so how am I?

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Great, I mean you're standing a little
close to me, but pretty great.

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Already we're seeing the importance
of user experience right?

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That prompt made me feel uncomfortable.

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So I'm gonna press Enter.

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And now, remember,
in the REPL we see the results show up.

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So what happens is when you call the input
function, it outputs out the prompt and

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then it waits for an answer.

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Once the answer to the prompt is given,
and

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the user presses Enter,
the result is returned.

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So we know that this input
returns a string, so

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let's capture it in a new variable.

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So let's see,
what would how are you today be?

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[SOUND] I guess that'd probably be
something like current mood, right?

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[LAUGH] Naming things is hard, isn't it?

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So we do current,

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and then we're gonna use the underscore,
cuz there's two words, right?

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So current_mood,
that's current mood in snake case.

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And we'll say, again,
we do the input, How are you today?

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Now, you know what, I'm gonna use couple
of spaces just to give some room there for

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user experience.

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So let's do this.

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So how are you today?

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Well, I am wonderful, especially
[LAUGH] now that you're not standing so

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close to me.

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And now our variable, current_mode,
if we just type that out here,

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we can see what's in it, wonderful.

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Awesome, so you know what,
we could just put this in our program.

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We could ask for
the user's first name, so let's do it.

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So we'll just replace this
value with the input statement.

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We'll say, what is your first name?

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And then we'll definitely
give them some space,

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cuz we want them to feel comfortable,
awesome.

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So now, you know what else,
let's scroll this down,

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let's get rid of these other lines
in here where we're saying hello.

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So I'm gonna Cmd+Shift+D that and
Cmd+Shift+D this,

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and let's bring this back up.

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There we go, that's looking good.

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00:03:01,820 --> 00:03:05,420
And it's saved, so let's go ahead,
I'm gonna drop out of the shell, Ctrl+D.

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I'm gonna clear the console, and
I'm gonna type python hello.py.

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So what is your first name?

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00:03:14,030 --> 00:03:16,800
I just got an email from one of my
students, so he's on my mind right now.

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00:03:16,800 --> 00:03:19,890
So I'll enter Kehinde.

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Hello, Kehinde,
Kehinde is learning Python.

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How's the weather in Nigeria
this time of year, Kehinde?

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And so you'll see that the first
name variable is now set to

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whatever we enter from input.

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So the program changes based on our
user's input, which is awesome.

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Because now we're dealing with input and
output, the staples of application

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development, great job.

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00:03:49,540 --> 00:03:54,100
We stumbled right into a fundamental
problem that you're gonna encounter daily

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in your coding journey,
naming things is hard.

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Now you'll get better at it,
[LAUGH] but it's never easy.

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And I can't stress this enough,
a good name is really important.

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You wanna be able to look at your code and
understand and remember what it's doing.

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00:04:10,322 --> 00:04:12,460
You wanna be able to read it next week.

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Now one thing to remember, and most people
who are just getting started coding

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don't think about this too often,
other people are going to read your code.

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Now, that might seem like a totally
foreign idea, but ready for this?

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You're going to be most likely on a team,
and

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00:04:28,420 --> 00:04:31,440
your teammates will need to understand
what you are trying to communicate.

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00:04:32,610 --> 00:04:34,960
We already know that
the computer has rules for

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understanding what we're talking about,
right?

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00:04:37,280 --> 00:04:38,580
That's called syntax.

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00:04:38,580 --> 00:04:40,700
But what we're talking
about here is coding style.

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[SOUND] There is absolutely nothing
stopping you from using a single letter

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00:04:44,888 --> 00:04:48,007
variable name for
the current mood code that we wrote.

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00:04:48,007 --> 00:04:51,770
Like I could store the result from
the prompt, how are you today,

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00:04:51,770 --> 00:04:53,150
in a variable called m.

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00:04:54,280 --> 00:04:58,750
But, I can guarantee that your actual
real life mood is going to change for

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00:04:58,750 --> 00:05:00,340
the worst, when you read this code and

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00:05:00,340 --> 00:05:03,670
have to try to figure out,
what does m mean?

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00:05:03,670 --> 00:05:08,790
Great news though, the Python community as
a whole are very big on consistent style.

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00:05:08,790 --> 00:05:11,390
Chances are after you
learn the style rules,

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00:05:11,390 --> 00:05:16,270
your code will be indistinguishable
from that of a long time Python coder.

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00:05:16,270 --> 00:05:19,650
I'll point these standard style
decisions out as we encounter them.

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00:05:19,650 --> 00:05:23,930
The one we've seen already is use
snake_case for variable names.

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00:05:23,930 --> 00:05:27,930
Now it's definitely not a syntax error,
you could use another casing system,

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00:05:27,930 --> 00:05:30,300
like for instance,
you could say currentMood.

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00:05:30,300 --> 00:05:33,695
This is called camel case,
each word here has a new hump.

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00:05:33,695 --> 00:05:38,340
[SOUND]
thisIsAnExampleOfWhatCamelCasingLooksLike.

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00:05:38,340 --> 00:05:42,002
If you're working with a team on
a project, you'll wanna make sure that you

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00:05:42,002 --> 00:05:45,170
follow the same style that is
being used in the project.

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Try to stay consistent.

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00:05:46,970 --> 00:05:48,720
So, how are you feeling?

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00:05:48,720 --> 00:05:50,870
You've picked up quite a bit
of information over these

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00:05:50,870 --> 00:05:52,100
past couple of videos.

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00:05:52,100 --> 00:05:54,990
I know that it's a lot,
especially if this is your first language.

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So let me say again,
great job sticking with it.

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What you've been learning will give you
a great foundation to dive deeper and

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00:06:00,950 --> 00:06:02,350
explore the language.

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00:06:02,350 --> 00:06:05,970
We've got the starts of what every
application has, input and output.

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00:06:07,040 --> 00:06:10,110
Next up, let's start processing
that input that we receive,

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right after this quick break.