# 2. Getting started¶

It is customary for language tutorials to start with a plain "Hello World" and as such an adherent to tradition that I am, I will do no less:

[1]:

print("Hello world")

Hello world


This should simply output:

Hello world


It is a very simple example where we pass the string "Hello world" to the function print which, well, print stuff (for those who don’t know, a string is sequence of characters, that is, a bunch of text).

We could make this a little more interesting, though:

[2]:

somevar = "Hello world"
print(somevar)

Hello world


Which gets us the same output, but now, we first “store" the string inside the variable somevar, and then ask the function to print it for us.

[3]:

#This is a Hello world in Python
somevar = "Hello world"
print(somevar)

Hello world


Just like bash scripting, everything that goes after # will be ignored by the Python interpreter. Now, lets try doing some math with integers:

[4]:

someint = 12
someotherint = 23
somemath = someint + someotherint
print("Result:", somemath)

Result: 35


Which should simply output:

Result: 35


Note that the print function allows us to pass multiple arguments to it, and automatically concatenate them for us.

Now look at this other example using decimal numbers (called floats on Python).

[5]:

somefloat = 3.43
someotherfloat = 1.4
amultiplication = somefloat * someotherfloat
print("Result:", amultiplication)

Result: 4.802


Which should output:

[6]:

Result: 4.802


Let’s also try something more “complicated":

[7]:

somefloat = 3.43
someotherfloat = 1.4
amultiplication = (3.24 + somefloat) * someotherfloat
print("Result:", amultiplication)

Result: 9.338


Which should output:

[8]:

Result: 9.338


Note that, as your High School teacher always said, multiplication takes precedence over division:

[9]:

somefloat = 3.43
someotherfloat = 1.4
amultiplication = 3.24 + somefloat * someotherfloat
print("Result:", amultiplication)

Result: 8.042


Which should output:

[10]:

Result: 8.042


## 2.2. Exercises for delving deeper¶

You may now want to use the function type to check the type of those variables, like this:

[16]:

somefloat = 3.43
someint = 1.4
somestring = "ske"
someotherstring = "2321"
type(somefloat)
type(someint)
type(somestring)
type(someotherstring)
type(someint + somefloat)

[16]:

float


Also note that none of these will work:

"2321" + 32
"2323.1" + 32
"2323" + 32.1
"2323.4" + 32.1


So, don’t try to add a string to an integer.