Syntax: List Indexing and In Keyword

In Python, lists store multiple items in a single variable. List items are ordered, changeable, and allow duplicate values. List items are indexed, with the first item having an index of 0.

days = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday']
print(days[0])
print(days[3])

> "Monday"

> "Thursday"

Python also allows negative indexing, where -1 refers to the last item, -2 refers to the second last item, and so on.

print(days[-1])
print(days[-2])

> "Friday"

> "Thursday"

The 'in' keyword can be used to check if an item exists in the list.

if "Wednesday" in days:
  print("Yes, 'Wednesday' is in the list days.")

> "Yes, 'Wednesday' is in the list days."

Practice: Retrieve Item at a Specific Index

1. Create a list named fruits and assign it the values "Apple", "Banana", "Cherry", "Dragon Fruit", "Elderberry".

2. Print the item at index 2 from the list.

Run your code and confirm that the output is "Cherry".

> "Cherry"

fruits = ["Apple", "Banana", "Cherry", "Dragon Fruit", "Elderberry"]
print(fruits[2])

Practice: Check if an Item Exists

1. Create a list named fruits and assign it the values "Apple", "Banana", "Cherry", "Dragon Fruit", "Elderberry" if you haven't already.

2. Use the 'in' keyword to check if "Banana" is in the fruits list and print the result.

3. Use the 'in' keyword to check if "Grapes" is in the fruits list and print the result.

Run your code and confirm that the output is True for "Banana" and False for "Grapes".

> True

> False

fruits = ["Apple", "Banana", "Cherry", "Dragon Fruit", "Elderberry"]
print("Banana" in fruits)
print("Grapes" in fruits)

Good job! Your understanding of lists, their indexing, and the 'in' keyword in Python is improving. This knowledge is very useful when dealing with sequential data in Python.