The list is perhaps the most commonly used data structure in Python. It allows us to store elements of different data types in one container.

The contents of a list are enclosed by square brackets, [].

Lists are ordered, like strings. Elements are stored linearly at a specific index.

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We can see from the illustration above that a list bears resemblance to a string.

A string is a collection of characters indexed in a linear fashion. A list is the same except that it can contain any type of data, even another list!

Creating a List

Let’s see how to create a list using square brackets.

The if and else blocks will remain the same. The elif statement comes in between the two.

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Let’s write an if-elif-else statement which checks the state of a traffic signal and generates the appropriate response: