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Hello and welcome to this video.

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This video is going to be the part one of a series of videos on creatine a calculator with Python.

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The first thing you need to do is open up a python shell so the way you access it is fine.

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The python folder so if you go into your program file as a python folder and just click on the Idol

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and that will launch the shell.

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So once you've got the shell open we need to open up a new file so click on File.

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New file and this file here is where we will write the code that will build the calculator the first

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and I recommend you do a save this file save as a python file so you do safe has and then keep it whatever

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name you want.

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He's already got the python file format here so you don't need to worry about that.

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Just give it a name.

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I'm going to call mine calculator

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calculator and I just press save and that will save it.

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I wanted to save on my desktop so I click save.

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So this file now is now a python file.

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The first thing I want to do is import a library.

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The library I want to import is called T counter is a library used to generate or create graphical user

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interface.

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So to do that we need to import it.

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So you type in from then you specify the name of the module.

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So this is a module is called teak into space and type in the word import space Asterix and that will

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import the library into the application for me to you.

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The next thing I want to do is create a class a class basically is a template for creating objects.

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So our typing class followed by the name I want to give the class I'll call it application.

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And when you create a class you can also passing arguments all parameters into it and I'm going to pass

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him a frame has an argument into that class.

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And when you create a class you also have to put a call on there.

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So this would be the main class for the calculator.

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Not as a passing frame that a frame basically is used to group and organize other widgets.

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So it's kind of like a container object for all the widgets the application is going to use.

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So inside this class I'm going to create a function or a method so to define a function you type in

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the what the f followed by the name.

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So I'm going to use the in it c to underscore in it on the score and then in parentheses is who are

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passing the any arguments I want inside that function.

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This on the score you need on the score function is a special function that is called when an instance

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of a class is created.

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So you use that to initialize that instance.

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So inside the parentheses I'm going to pass same two arguments.

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I'm going to passing herself variable and master the self is a reference to the current instance of

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the class.

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OK.

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And that's what that self is.

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And then the master represents the parent widget.

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So now let's initialize the frame so to initialize the frame we're going to use a special built in function

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and the built in function is called Super.

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So inside the parentheses are passing some of the super function is a built in function which returns

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a proxy object to delegates.

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Method calls.

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So he uses that to delegate method calls to a class which can either be a parent or a sibling in nature.

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So inside a super function I pass Tim the application class here and also a reference to the cell variable.

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And here I'm using the underscore in it again initialize the master widget.

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This master also is known as the parent widget so we initialize in it.

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Here to save time I've added a few lines of code here.

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I've added these lines of code so this self again is a is a variable.

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It's a reference to an instance of a class or an object that is created.

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So here I am set in these two blank and then here I'm using the self again the user input.

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This was going to be a user input variable and I've set that to equals to this string.

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Var basically this string var is going to hold a string and the default value is blank.

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But I've set this to make sure it holds a string value.

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Then here we've got the create method.

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The grid metal basically is used to register a widget with the great geometry manager.

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So if you don't do this the widget will exist internally but it will not be visible on the screen so

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the greed is used to register widgets with the jewel military manager.

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The geometric manager is used to manage the placement and the layout of the elements of the go to create

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on the score widget function which will use to create widgets.

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So that's it for this part.

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Thanks for watching.

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Bye for now.