5 - Iteration

The following code repeats the same task twice:

word = 'Lilian' 
print(word) 
print(word)

If we wanted to write a script that print the same thing a thousand times, this approach would be impractical. Thankfully we can do the same thing more concisely via iteration.

In programming, iteration refers to the process of repeatedly executing a block of code until a certain condition is met. Iteration is often used in loops, which allow you to iterate over a sequence of values or perform a certain operation a specific number of times.

There are two main types of loops in Python: for loops and while loops.

for loops are used to perform a certain operation a specific number of times or to iterate over a sequence of values, such as a list, tuple, or string. The for loop is also referred to as a count-controlled loops.

To print my name a thousand times can be done concisely with a for statement as shown below.

word = 'Lilian' 
for i in range(1000): 
    print(word) 

This is the simplest use of the for statement; we will see more later.

while loops, on the other hand, are used to iterate until a certain condition is met. They are sometimes referred to as condition-controlled loops.

In both cases, iteration allows us to execute a block of code multiple times, which can be useful for performing repetitive tasks or iterating over a sequence of values.