--Originally published at Quirino´s Projects

A very useful data type in python are dictionaries, these could be understand as a list, but each element its a key with its respective value e.g.

We can have a list that holds every word in the english alphabet, but if we wanted to create a program that holds the number of times a letter appears in a string, creating a variable for each letter would be that practical, so a dictionary would be useful

alphabet = {“A”:0,”B”:0,”C”:0,”D”:0…}

Now we have a dictionary that holds a numerical value for each letter, the sintaxis of the dictionary is the following

{} The curly braces contain the dictionary

: The colon separates the key from the value of the key

“A” This is the key, it holds the value next to it

0 Its the value of the key

If we would like to add elements to our dictionary, we simply assign a value to a key is if it was already there

alphabet[“E”] = 5

A useful function when you are working with dictionaries is dictionary.keys(),this function returns the keys in a dictionary as a list, so we could check if a key is in the list before doing something with it

To get more info about dictionaries check:

https://www.tutorialspoint.com/python/python_dictionary.htm

--Originally published at Quirino´s Projects

This a little bit hard to catch for early beginners, but trust me these are really easy once you understand how the functions are made.

Sometimes we want to do something many or several times in our code changing only a number or a string, and repeating ourselves makes our program harder to read

This is were functions become our ally

If we wanted to get the factorial of 3 numbers, without functions we would need to do this:

num1 = int(input(“N: “))
result1 = 1
for i in range(1,num + 1):
result1 *= i
num2 = int(input(“N: “))
result2 = 1
for i in range(1,num2 + 1):
result2 *= i

num3 = int(input(“N: “))
result3 = 1
for i in range(1,num3 + 1):
result3 *= i

print (num1)

print(num2)

print (num3)

Using the for loop each time makes a bulky code, so instead we could use a function

def factorial(num):
result = 1
for i in range(1,num+1):
result *= i
return result

To explain how a function in python works we need to see each part

def

Stands for define is the keyword needed to tell python that the next thing will be a function

factorial

This is the name our function has and the name it will be called with it can be any name but there are a few conventions about naming things in python

Please Check https://www.python.org/dev/peps/pep-0008/

(num)

These are why functions are a bit hard at first, num is the argument that is passed to the function we defined just one, called num but a function can have as many arguments as we want, this argument is used locally inside the function and we cannot edit it outside the function block for easier understanding lets look at this code

def numberTimesThree(num):

    return

Continue reading "Creating functions" →

--Originally published at Quirino´s Projects

#Go ahead try this in your python3/2 console

import this

#Just go to shell enter python3/python2 and paste that

Write easy to read code

#Python comes helpful to teach you how to indent your code
#Since it won't run if you don't
#Indent makes it easy to understand nested code
if 1 == 1:
    for i in range(5):
            print ("This is the range of 5")
            for x in range (45):
                if i = 5:
                    print("We are in the range of 5 of the range of 5")
#Of course this is a pretty bad example but i think you get the drill
#With indentation you know what things belongs to where

Useful external sources: