So programming, basically computers are just big calculators, they cannot do anything except add, compare and store values. Programming is the process of writing many of these basic commands in sequence to instruct the computer to do something. Although at the core all a computer can do it add, compare and store numbers when you are programming you are able to perform many more tasks, this works because code which is the actual programming text works for you, other code can interoperate your code and simplify other difficult tasks for you.
So you want to learn how to actually program, I am going to show you the basics of python. Python is an interpreted, high level language (don’t worry about what that means if you are just learning, say it to people to make you look smart and even better them look stupid).
To get started download Python and save any “scripts” (programs) and text files with the .py extension, you should then be able to open them with the python interpreter and run them.
Alright onto the actual code, programs consist of commands, the first of these commands is variable assignment, so variables are like boxes, the box can hold anything and the contents of the box can change. Like x in math.
myFavouriteNumber = 8
So this will assign 8 to the variable myFavouriteNumber, anytime myFavouriteNumber is written the value 8 will be used.
So we have our special variable, we want to show the user. Python provides a function just for this, the print function displays and variable passed to it on the screen. This opens another new topic, functions. Functions are smaller pieces of code that perform a specific tasks. You can run this code with a command structured like this
functionname is whatever the function is called, inside the parentheses you include comma separated values or variables which are given to the function as it runs. The function we are interested in was print remember? So if we want to display the number 10 we write
Simple right? So what if we wanted to print our favourite number. Well as I said before, variables hold values which are given any time a variable is used, so the command
Will display 8 on the users screen, make sense?
So what if we wanted to display the actual words ‘myFavouriteNumber’ on the screen, well that brings us to our next type of data. Strings.
Strings are a series of characters which is a fancy way of saying a string holds words.
When we want to represent a literal number we can just type the number as we did earlier when defining myFavouriteNumber, when representing literal strings we must use quotation marks to specify to the computer that we are trying to give it a string instead of a command.
myFavouriteWord = “slut”
So if we run the command
Then the program will output the word ‘slut’ (without the quotation marks) remember that the quotations marks are only to tell the computer you are writing a string, they are not actually part of the string.
Variables are not required for strings, same as numbers, so we could also write the line
And we will get the exact same result.
So this shows that variables here are somewhat useless. Where variables come in handy is where the value is not known at any one point throughout the program.
So I will introduce a new function; input the input function pauses the program and waits for the user to type some text in, which is then read into a string.
so the function looks like this
answer = input(“What is your name? “)
So this shows a new feature of functions. Return values, functions often have a result or value to give back to the program, in the case of the input function the value that the user typed in is returned. Return values become the value of the function when executed. This may sound complicated but think of them like variables, where ever a variable is used it’s value takes it’s place. Same goes for functions, when a function is hit it is run and its return value takes it’s place.
The example input function has an argument passed to it, which is a string (“What is your name? “) this function prints the string at the beginning of the line waiting for the user to type in a response, it is there to pass a question to the user to respond to. The return value of the function is then stored in answer once it has run.
so lets write a little program with the knowledge we have.
question = “What is your favourite colour? ”
theirFavouriteColour = input(question)
print(“Your favourite colour is”)
So this is pretty basic but have some fun with it, I will post another tutorial at some point over the next week. Enjoy.