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Let's now improve that if structure.

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So with what we've seen, we can execute this
block of code if that condition is true.

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But what if you want
to execute a different

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set of instructions if
the condition is false?

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So you want to test if it's
true, execute something,

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and if it's false, you
execute something else.

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Well, let's see that.

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So first I'm going to come back to the
first statement here to make it very simple.

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OK.

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User age greater or equal
than 18, you are an adult.

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And then I'm going to come back.

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So I press Enter.

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And I go back to the first indentation.

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And I write else with a color.

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I press Enter.

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I have a new indentation.

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Print you're not an adult yet.

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So in this case-- so first is
going to check if that is true.

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If that is true, it's going to execute
the next indented block of code.

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And if that is not true-- so if
this is false-- we go to the else.

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And then we can execute that block of code.

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So now let's run this.

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OK.

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So we still have the same
time and end of program.

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But you have you're an
adult because user age is 30.

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Now you're going to put 17.

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And you can see you are not an adult yet.

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So you can use if and else.

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And you can also add
intermediate conditions

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with else if or in
Python it's named elif.

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And let's see that
with this structure here.

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So I'm first going to modify this.

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OK.

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Because summertime is actually--
so from the north hemisphere--

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it's June, July, and August.

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OK.

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So let's say if month
in June, July, August.

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So we use the test here to
check if one value is in one list.

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OK.

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So if the value is June or July or August,
it's going to work and print summertime.

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Let's just test that.

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OK.

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Summertime.

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Now what if I want to
test if the month is actually

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in the wintertime or the
springtime or the Autumn time?

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What I can do, I can use elif.

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OK.

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Not else if.

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OK.

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Else if can be in other languages.

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But for Python, this is going to be elif.

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Month in-- let's say we want to
test September and then October.

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And then November,
we can print Autumn time.

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So what's going to happen is first, it's
going to check that this condition is true.

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If yes, it's going to execute
that block of code and then exit.

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OK.

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Once a condition is true, a
block of code is executed.

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And then the if will exit.

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If this is not true, it's
going to go to the next

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elif, if there is one,
and check if that is true.

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If that is true, it's
going to execute that.

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And if it's false, it's not
going to execute anything.

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And then any of the block
here will not be executed.

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And we continue the execution here.

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OK.

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Now I'm going to add another elif.

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Month in-- so let's do all the year.

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So November, we have December.

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And then January.

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And then February.

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OK.

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If the month is in that range,
we are going to print wind time.

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And then-- so here we still
have three months in the year.

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OK.

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We have March, April, and May.

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I could do elif month in
March, April, and May.

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But I can just do els.

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Because, well, that's the
only possibility that's left.

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So els print spring time.

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We first check if that is true.

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We print summer time with exit.

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If that is false, we check this.

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If this is true, we print
out on time and exit.

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If this is still false,
we continue with this.

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And if this is true, we print winter time.

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If this is still false, we go to the els.

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And then we print spring time.

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OK.

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So we have July, which is summer time.

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Let's test with September.

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You can see Autumn time.

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OK.

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Because this is false.

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This is true.

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So we execute that.

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And then we skip all the rest.

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Now let's say May.

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You can see spring time.

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OK.

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We are in the pets.

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So you can test here with different values.

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OK.

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To see where you end
up in the if structure.

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All right.

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Now you are able to
use if structure to choose

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what to execute depending
on different conditions.

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This will allow you to make your
programs much more dynamic.