WEBVTT

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So in the previous video we drew
attention to the fact that there's code

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warnings in IntelliJ, and they're those
dashes you saw on the right hand side.

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So, right at the moment now we
haven't typed anything in, but

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you'll notice the little green arrow
there, which is actually indicating that

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there's no actual errors in the code or
no warnings.

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So as I start typing, i'm gonna actually
type in the program that we actually typed

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in in the last section.

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Notice the little warnings
that actually come

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up, the little lines as I type.

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So I type number=9223372036854775807.

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So far, so good.

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You'll notice there's a little I
there showing as I was typing and

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that it actually ended up with a t.

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So as I'm typing,
it's actually scanning and

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giving us errors if
there are errors there.

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So cleaned number, equals double quote,

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double quote gives us two quotes, and
I'll add a few more spaces there so

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we can be clear about what
we're trying to do here.

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So, for i in range, just going to
type this program in again now,

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0, len(number), again,
this is the old version.

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If number

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I in 0123456789, then we're gonna do

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cleanedNumber = cleanedNumber,
plus number I.

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And it's just a couple more lines.

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New number, whoops,
getting our indentation numbers correct.

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New number equals int,

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clean number,
then print into the top of there.

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Come back to the minute print,
the number is

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.format(newNumber) and fix that typo.

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And again notice that when you
have actually made a typo,

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it does actually appear as
here as some warning as well.

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So type int.

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Fix that up.

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So if you actually type it in, exactly as
I've typed it in here, the first real code

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of course starts on line three, the number
we're actually assigning the value

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into a number variable, you should see
a marker at the end of line eight.

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So coming down here,

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there's actually one on line three as
well, missing white space around operator.

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So what I should have done there is put,
= and a space, like so.

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And that will get rid off that one.

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But the one we wanna look at first,

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before we get started,
is this one here on line eight.

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So if you hover over
this with a mouse again,

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it says, assignments can be
replaced with augmented assignment.

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And again, with these warnings we're
already on that line, but if you click on

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them you will actually go for that
line and sort of parse button as well.

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You can start editing it as well.

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So in this case,
this is actually not an error.

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It's more of a suggestion, but given that
in the last videos I recommended you

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checking out these markers,

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this is actually a good place to
discuss the augmented assignment.

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Which of course is not what
it's actually asking about,

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it's actually mentioning that maybe we
should be using augmented assignment.

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So I know augmented assignment
sounds really fancy, but

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it's really just a short-hand way
of assigning values to a variable.

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Now the Python documentation describes
them as the following, the combination in

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single statement of a binary operation and
an assignment statement, which is true but

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If you're like me, listening to that
doesn't sound terribly understandable.

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So in line eight we performed
the concatenation of clean number plus

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number i.

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Then we assigned the result
to clean number.

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So the concatenation is
the binary operation.

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Binary because it takes
two upper ends to work on.

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And then of course,
there's the assignment after that.

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So what you could do to change this to
an augmented assignment, we could instead,

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I have this example I've
done here on line eight.

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We could have actually done this,
+=number i.

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When we do that, the warning indicator
over here has now disappeared,

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and it's telling that this
is a more efficient way.

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It's a short hand way for
what we had in the past.

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Now if you're used to programming in Java
or C++, and particularly if you used

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IntelliJ ,then you would find that
IntelliJ doesn't make this suggestion for

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those languages,
because both statements are identical.

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The use is just really
a matter of preference.

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So whether you typed it in the long way or
the short way with the plus equal,

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as far as Java or C++,
which is two examples of languages.

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It makes no difference.

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Thing to keep in mind though, is that in
Python the augmented assignment form only

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evaluates the signee, which is
the clean number in this example, once.

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So, in the other form,
where clean number appeared twice,

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the variable is evaluated more than once.

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So, basically there's more work for
the computer to do.

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So, it's actually processing
that more than once.

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And also with the first form,

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plus the long winded way with clean
number equals clean number plus one.

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Python actually creates a new variable
in memory, assigns the value after

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performing the calculation,
then destroys the original version.

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Now using an augmented assignment
can perform the operation in place,

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with possible modifying of
the original variables.

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So there's less work.

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There's one less variable.

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In this case it would be created
internally from Python's perspective, and

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it's going to be more
efficient in most cases.

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With that said, it's not always possible,
depending on the type of object.

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We have the variable, in other words,
in question to the do this.

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But it can be done in
place wherever possible.

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And that's why in this case IntelliJ,
when you're using Python with IntelliJ,

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it's suggesting that you use augmented
assignments rather than longhand.

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Because unlike Java and other programming
languages, the shorthand way with the plus

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equals in this particular case
is actually a lot more efficient

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from Python's perspective, and
you'll ultimately, as you start writing

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real Python programs you're going to be
finding this is more efficient, and you're

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going to be actually saving resources
which is actually very important.

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And just a reminder that
this last line here,

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this last warning, it's saying there's
no new line at the end of file.

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We fix that by just creating an empty line
and that will actually remove that error.

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And we should in due course get
a little tick that'll appear up here.

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And again as I mentioned
the term augmented

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assignment sounds a lot more complicated,
and it really is.

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Sounds like it's a fancy term.

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It's really just a short
hand way as you saw.

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So the symbol for

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them is just like typing the binary
operator followed by an equal sign.

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So you could do something similar.

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You put plus there, but
you can use other ones.

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You can use the minus, and that would
be the equivalent to clean number=clean

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number, type number i, which doesn't make
sense in the context of this string, but

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it might be if you're
actually adding numbers.

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You could also use multiplication.

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That would be star equals like that.

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And then you could use slash for
division slash equals.

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So let's actually go through
an example of a couple of these so

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they actually make sense.

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So we can start by saying
x equals twenty three,

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then we could put x plus equals one.

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So applying this to numbers
makes a lot more sense.

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We put x of course we should
get the value twenty four.

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So if we run that I see we got
the value 24, so no surprises there.

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Then if we actually put x -= 4 and

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print that out again that
should be 24 take four.

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We should get the answer 20.

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And there's a second answer there,
it's 20, which is correct.

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And continuing on from
that we can write x=x*=5,

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that's what it is,
it's the abbreviation for it.

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And that should be 20 times 5 and
that should give us 100 when we run it.

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Let's say we've got 100 there and
if we try division x/=4,

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so x equals x divided by 4,
in other words.

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That should give us an answer of 25.

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Bearing in mind it's a flighty answer
because we only used a single division.

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And from there we could have done
something like x star, star equals two.

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And print that out and we should
get the answer of 625.0 from that.

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And of course if you recall star,
star is to the power.

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So it's basically 25 to the power of 25,

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which was to the power of 2
I should say which was 625.

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And lastly from our
remainder process x like so.

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If you print x from there, so
we're looking for the remainder.

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I've divided what the current value of
x is by 60, if we actually run that.

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We get the answer of 25.

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And that's because 60
goes into 625 ten times,

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leaving a remainder of 25, and the number
25 is what the answer is to that.

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And just to finish off, we can actually
apply some of these, binary operators.

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There's also two binary operators
that can be performed on strings.

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Concatenation which we've seen, but
we'll do again and also repetition.

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So we could put greeting = "Good"

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(greeting)+= "morning" print (greeting).

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We can actually run that.

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We have good morning, so you've seen
the pluses before for catanation purposes.

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But we can also put this.

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We can put greeting *=far so
it's actually replicating by repetition.

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The current contents of the string
if you actually print that out.

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You can actually run that.

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And we get good morning, five times.

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And we could've added a space here.

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Then run them again if you wanna them a
little bit more nicely across the screen.

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And you can see it's repeated five times.

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They're the only binary operators
that actually work with strings.

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Now there's five more binary operations
that we haven't yet looked at, but

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we're gonna leave those for later video.

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I'll actually just paste you a list
of what they are on the screen now so

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you can actually see them.

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So we've seen some of them.

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We've seen a lot of them.

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But some of these other ones here, less
than, less than, equals, greater than,

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greater than,
equals ampersand equals, and so on.

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So we'll actually see those and
be talking about those in a future video.

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So that's the end of this video.

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In the next video, it's time for
a section challenge.

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So, we're gonna summarize what we've done
to date in this section of the course, and

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then we're actually gonna come up with a
challenge to hopefully help you understand

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all the concepts that you've
actually learned in this section.

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So, I'll see you in that next video.