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Hello and welcome to this video.

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This is gonna be a three part video series where we are going to create a count down timer using Python.

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Calm down time has a very useful.

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You can use that to count down to several events for example.

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Holidays and other related events that are of interest to you to begin our development.

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You need to open up the python shell and you can access it.

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Fi your programs menu inside the python folder there is the idol just double click on the idle and that

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will open up this shell.

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So once you've got the shell open we need to open up a new window.

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So you go file a new file and inside this area here we will develop our application.

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So the first thing you need to do is save the file so you do file save as and you can save it anywhere

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you like but just save it with a dot P Y extension actually you don't need to because it's already done

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that for you here or you need to just give it a name.

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So I'm going to call my count down and I'll just save it and I'll save it on my desktop.

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OK.

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So I've got the file so this now is a python file.

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I want to use some Python libraries.

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So before I use them I need to import them.

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I'm going to import t counter which is a module that is used to create user interfaces of various types.

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So to import that I just need to type typing from space teak into

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King ter can't spell today Kintore.

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That's it from TI Kintore.

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They type in the word import

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space Asterix.

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So with the asterisks it will import the library mix who want to import whole nother library.

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It's also a subset of T Kintore to do to take into space import space.

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This one's called t t k.

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Next we won't import a t type font.

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So we can use a font from t kin to you type in the word import followed by or too important to import

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in the font element.

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Next I want to import the time module so I'm just typing.

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Import time I also want to import the date time so I type import

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date time.

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All right.

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So I've got all my libraries and class methods ready.

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First thing I want to do is create a variable.

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It's gonna be a global variable a global variable means it will be available throughout the application

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Python variables are scope base where you can have a variable that is local or exist only within the

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module but by declaring it global that means I want the available throughout the application so I just

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type in the word global followed by the name I want to call it.

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I'm going to call it and times who will use that later in the application.

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So I want to create our first function here and to create a function you type in D F followed by the

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name.

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I'm going to call this can't underscore wait I'm going to be the name of my function actually before

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I create that function I want to create another one of us not create a function called quit.

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This will allow us to quit the application and inside the parentheses I'm going to pass it arguments.

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Okay.

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And that's it and semicolon you use the asterisks and the KRG is which stands for argument.

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So what you normally do when you're not sure how many arguments might be passed to your function you

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used the asterisks and eggs.

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What that does it allows you to pass an arbitrary number of arguments to your function and inside this

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quit function.

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I'm going to had a root metros and was a root dot this Troy

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what the root dot destroyed does it will cause the main loop of the application to exit.

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So when the application kept running and this font with this function of this method is called it will

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exit the application from the look.

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One more thing I want to do before we wrap up this video lecture I want to create on another function

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this time I'll call it

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can't on the score wait but feel free to call use whatever you like.

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And then the parentheses and the call on and I'm going to create a variable and I'm going to call this

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variable time left and and went to set that to a course to the end time variable which is this variable

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here.

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The global one so I'm certain it two equals two that minus the date time dot the time date time the

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day time dot.

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Now that this is method a time function we've imported the day time and the time module has we're able

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to utilize it here.

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This will give us the current time.

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So if we take away B value of this and time from this method here it will give us the time left over

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for our event.

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I have added some more line of code so as to save time so a mother this line here.

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What this does it takes away the micro seconds.

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Okay.

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So if without doubt the time would display after the cyclone Yasi tore through so sure some microseconds.

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So I'm using this value here to take away the microsecond so that we don't have that displayed and then

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here I have created.

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This is what will display the clock.

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Ok this will show the time that is left to your particular event.

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This is what we've used to set that time.

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And this here this piece of code here is used to trigger the countdown after one thousand milli seconds.

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So I'm going to end this lecture here and we'll continue in part to where we'll start to build the interface

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for the countdown clock.

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So make sure you save your work.

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Just keep files save and we'll see you in part two.

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Thanks for watching.

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Bye for now.