# 
## Overview
In Python, a **list** is a data structure that is a changeable/mutable and ordered sequence of elements. Each element or value present in a list is called an **item**. 
>In a Python program, lists are defined by having values between square brackets `[]`.

## Example

From the example given above, `countries` is a list variable, while `USA`, `CHINA` and `TURKEY` are all elements of the list.

## How can we loop through a list in Python

To loop through a list in Python means repeating something over and over the items of a list, until a particular condition is satisfied.

We can loop through a list using a **`while` loop**. Here, we use the `len()` function. The **`len()` function** is used to determine the length of the list we created. This function starts the iteration at the `0` index, going through all the items of the list by referring to their indexes.

## Code example



# creating a list
countries = ["USA", "CHINA", "BRAZIL", "TURKEY"]

# starting at 0 index
i = 0

# using a while loop
while i < len(countries):
  print(countries[i])

  # giving an incrememt of 1 to i
  i = i + 1

## Code explanation
* **Line 2**: We create a list named `countries`.
* **Line 5**: We create a variable `i`, to represent the index numbers of the items of the list starting with index `0` (`i=0`).
* **Line 8**: We create a `while` loop and use the `len()` function to iterate over the list by referring to all the index numbers of each items of the list.
* **Line 9**: We print the elements of the list.
* **Line 12**: We increment `i`, which represents the index numbers of the list by `1` (`i = i + 1`).

How can we loop through a list using while loop in Python

Loop through a list in Python using a while loop by iterating over indexes from 0 to len() - 1.