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And one last thing I want to show you about
Python OOP is the concept of composition.

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Let's say that now you have to
work with a packaging solution.

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This packaging solution is
nothing more than two robotic

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arms assembled together
to work on an assembly line.

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What you can do here is
to create a class, I'm going

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to create a new class here,
class, packaging, solution.

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And inside this class
you're going to keep and

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use two instances of
the robotic arm class.

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This is what we call composition.

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Basically when you use an object
from another class inside of a class.

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So let's see with this example.

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I'm going to create a constructor here,
so def init, and I'm going to pass it.

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So let's say we have a robotic arm on
the right and a robotic arm on the left.

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I'm going to name it
robot right and robot left.

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And do self.robot right
is equal to robot right.

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And then self.robot
left is equal to robot left.

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So I create two attributes
of the class which are

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going to be two objects
from the robotic arm class.

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And then I create a new
method def, let's say package.

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We are going to add some parameters.

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So let's say pick x and then pick
y and then place x and place y.

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The coordinates we want to pick
and place the object from and to.

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And I'm going to also
add middle x and middle y.

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So I'm going to make the two robotic
arm collaborates between each other.

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So what I can do, for example, I can do
self.robot right.pick object with pick x.

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And pick y.

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And then self.robot right.place object
with, let's say middle x and middle y.

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And then self.robot left
this time, which is going

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to pick the object from
the middle x and middle y.

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And then self.robot left.place
object to place x and place y.

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So basically what I do
is I make the robot right,

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pick the object and place
it in the middle position.

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And then the robot left is
going to pick the object from

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that middle position and
place it in the place position.

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Okay, so that's just for the example.

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So you can see that we use the
instances of that class inside that class.

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So now this is ready.

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What I can do is go back here and I'm going
to do from robot import packaging solution.

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And I'm going to add a new robotic arm.

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So let's say robotic left.

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I'm going to call it left
in this one robotic right.

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Okay, this is going to be robotic arm.

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Let's call it.

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So Bob and John.

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Version two rage.

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Let's put 300 also.

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Then I'm going to remove that.

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I'm going to comment that.

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And what I can do now is I
create a packaging solution.

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So packaging solution is
equal to packaging solution.

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Okay, and I need to give two
parameters which are this time two objects.

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So robotic arm right first robotic
arm right and robotic arm left right.

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And so now I have two
objects here, but I also can

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use the object inside the packaging solution
class, which I'm going to do right now.

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I'm going to do packaging
solution dot package

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and then I need to
provide six coordinates.

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So let's put one two
three four five and six.

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Okay, let's keep it simple and let's run
that and you can see pick object on one to

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place object on three four pick object
on three four and place object on five six.

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Okay, so this when I call package
it's going to call the different

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methods from the robot right and
the robot left we have created here.

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Okay, which is going
to go here and then you

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can see print the pick
object and place objects.

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Great.

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So now you have both used the inheritance here and the composition concepts with
ROP and Python to quickly recap you can use inheritance when there is a relation

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where you can use the verb to be for example a robotic arm is a robot and you
can use composition when there is a relation with the verb to have for example,

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the packaging solution has two
robotic arms here we use composition.

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All right, that's the end of this
bonus section on ROP with Python.