--Originally published at Quirino´s Projects

When we want to repeat some code n times, depending on a variable, or until a condition is met, we can use While and For loops

For

A for loop takes a data type, could be a string, a list, a dictionary, and basically every type of data that can be access by its elements, and runs n times were n is the number of elements of the list, and creates a variable each loop with each element

And example, we have a list

myList = [0,1,2,3,4]

And we want to print each element individually, in this case we use the for loop like this

for i in myList:

print (i)

Here the i in the first loop takes the value of 0, then gets printed, then takes the value of 1, then gets printed, and so on the i becomes the value of the index of the list

Here is an example of a program that eliminates spaces from strings

myString = input(“Give me a string: “)

newString =””

for i in myString:

if i != ” “:

newString += i

print (newString)

This program checks each character in the string, if the string is different that a blank space, is not added to the new string

While

A while loop is a loop that runs the code within forever until the condition given is evaluated to False

while True:

print(“I will be printed for ever”)

This is a not correct way of using loop, but serves to explain for While

n = 10

while n <100:

print (“Value of number is {0}”.format(n))

n -= 2