Chapter 1

Chapter 1
Python, IDLE and your first program

In this chapter you are going to:

• learn about computer programming and the different languages that you can use
• meet the Python programming language
• learn how to use IDLE, which will help organise your programs and allow you to run them easily
• check that your computer has been set up correctly
• write and run your first program.

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Coding

• Coding is writing instructions for a computer to perform a task. 
• This code has to be in a form that the computer can understand. 
• This is more formally known as computer programming.

• Computers and coding have not been around for a long time but they have sure packed in some interesting history in a short space of time. 
• The first machine that stored instructions in a way that future computers could take advantage of was the Jacquard loom that used holes punched in cards and was invented in 1801. 
• Charles Babbage is often credited with inventing the first computer which he described in 1837 but was not built until 100 years later. 
• In 1989 Guido van Rossum started to create the Python programming language which he named after Monty Python’s Flying Circus, a BBC comedy sketch show.

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Programming languages

• There are many programming languages currently used by coders around the world. 

• Some are best in one situation, others in another. 

• HTML is good for producing web pages. 
• SQL is great at making databases do what you want. 
• Python is brilliant for writing quick applications, running programming experiments and for building larger applications, including games.

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Python

• Python is a typed computer language. 
• This makes writing short programs very fast and you can produce almost anything you can imagine.
• Python is a powerful, modern programming language used by many famous organisations 
• such as YouTube and NASA. 
• It is one of three programming languages that can be used to write Google Apps. 
• Python is a great language. 
• Enjoy!

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IDLE

• You will start programming in IDLE which comes with Python. 
• IDLE is a special text editor like Microsoft Word, 
• except it understands Python and helps you get your code right. 
• IDLE is itself, a Python application.

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Hello World!

• Since the dawn of programming, when the first cave-coders booted up their cave-computers, it has been a tradition that your first program when learning a new language is ‘Hello World’. 

• The aim is to try to make the computer say ‘hello’ to the world. 
• If you can do this you will have tested whether everything that was set up for you is working properly.

Code Box 1.1

print("Hello World!")

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Making mistakes

• Syntax errors are very common when typing in code (as are other errors). 
• If you make one or two it is not your fault. 
• It is because although computers are fast, they can also be a bit stupid. 
• If there are any tiny mistakes in your code, they panic and produce error messages.
• These messages try to explain to you what the problem is but they are often difficult to understand.
• Colons, brackets, speech marks, apostrophes and spelling of Python words have to be just right.
• Although we can read imperfect sentences, computers cannot.

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Chapter summary

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