Introduction to Programs Data Types and Variables

Writing a basic program. Basics of data types, variables and conditional statements

What I want to do in this video is to introduce you

to what a computer program is.

I highly recommend you follow along

because the real way to learn computer science

is to really fiddle with things yourself.

This is a Python environment. I'm going to be doing a lot

of the programming in a language called Python.

This environment is called PyScripter. It's free,

it's an open-source piece of software and I believe

I'm using Python 2.6 or 2.7. As long as you are using

Python 2 your examples will be the same as mine,

They will work the same way. But If your using Python 3 you are going to have

to use slightly different variations every now and then

to make it work properly. I'll try to make notes for

those when they occur. So lets just start writing ourselves

a computer program. What's cool about this is, we can

write our computer program right here

and really we are just editing text in a file. That's all it is.

It's a set of instructions and the computer is just going

to start at the top of this file and just go down

and read the instructions., although you will see

later on that there are ways to tell the computer to jump

around and loop around within the instructions, so that

it can do things over and over again or skip parts of the program.

With that said lets write ourselves a simple program

and while we do this we will expose ourselves to some of the

core concepts that exist within a computer program.

So let me just write a very very simple computer program.

So one very simple computer program

would literally just be an expression.

So let me just write 'print 3+7', so it's literally

just going to take 3+7 and print it. It's going to pass

it to the print function which comes with Python

and maybe I will write like this: print(3+7)

Lets save this file. So there's literally only on command

here on the top line that says print 3+7.

Actually, let's add another command,

just so you can see that it's going to go top down.

let me add another one: print(2-1)

and lets do: print("this is a chunk of text")

Now let's see what this computer program is going to do.

Let me save it. I saved it as the file "testarea.py".

The .py extension signifies it is a Python file.

Now let me run the program. What's nice about these

IDE or Integrated Development Environments is that

you can type and run the program in the same place.

It also color-codes your text, so you can see what's a

function, what's not a function, the different data-types...

Let's run the program to see what happens.

So there we go, we ran it!