Python is one of the most popular programming languages in the world. It is a great introductory language praised for it's readability, ease of use, and versatility.
You can download Python at the Python website, but if you use Linux, OSX, or something in that vein, you probably have a version of Python installed. You can go into your terminal and type in python to drop into the Python interpreter.
If you're on Windows, download Python, install it, and find the IDLE program in your start menu. Run IDLE and you will find a similar environment.
From within the Python interpreter we can interact with Python and play with code immediately. The interpreter can act as a playground for our code and by entering code and hitting Enter, we can immediately see the results of our code.
For example, try entering 2 + 2 and hit enter. If you do not get back 4. Standard math right?
Here we have two 2's. They are known to computer scientists as integers. We also have the + sign. This is known to computer scientists as an operator.
Besides addition, we can do all sorts of math from within Python.
Python supports these mathematics operators:
+ - addition 2 + 2- - subtraction 4 - 2 or negation -2* - multiplication 2 * 2/ - children's division (rounds every number down) 5 / 3% - remainder or, as the cool kids call it, modulus 5 % 3** - exponent 2 ** 3You can use Python as a rudimentary calculator using just these operators.
We can also create variables in Python to store values.
Try typing in x = 2 and then typing in print x
You should recieve 2
print is a Python statement which outputs your data to what's known as standard output (aka stdin), standard out, or stdout. print is very valuable for seeing data that you've generated or for checking the value of a variable when debugging.
Here we also introduce the idea of assignment.
We are assigning the variable x the value of 2 by using the equals sign or assignment operator (=). In reality, Python's variables are more like names for data but that's a discussion for later.
Now that we've assigned x the value of 2 we can perform operations on x as if it was 2. That means instead of 2 + 2 you can type in x + 2 and you will recieve back 4.
We can also chain all these operators to do slightly more complex mathematics. x = 2 + 3 * 6. This expression evaluates out the value of 20 and stores it in x. Order of operations (PEMDAS) applies. We can be more explicit about the order and say x = 2 + (3 * 6).
And also if we wanted to do operations with x but not have to type it out twice (like this: x = x + 2) we can use a short cut by typing x += 2. This same shortcut can be done with all the other mathematics operators we've discussed.