A day planner must update a task, add a new appointment and remove a canceled entry.
What You Need to Understand
A list supports assignment by index, insertion before an index, and removal by value or position. These operations mutate the same list object.
When to Use It
A day planner must update a task, add a new appointment and remove a canceled entry.
Step-by-Step Python Example
schedule = ["call", "meeting", "review"]
schedule[0] = "email"
schedule.insert(1, "backup")
schedule.remove("meeting")
print(schedule)How the Example Works
The sequence becomes email, backup, review; the insertion shifts later elements and remove() deletes the first matching value.
Example Output
['email', 'backup', 'review']
[1, 2]A Second Example
Compare this smaller variation with the main example, then experiment with your own values.
values = [1, 2, 3]
values.pop()
print(values)Important Behavior and Edge Cases
remove() raises ValueError for a missing value; pop() raises IndexError for an invalid position. Check membership or handle exceptions where appropriate.
Try It Yourself
Replace the last task, then add one at the beginning.
Common Beginner Mistakes
remove()raisesValueErrorfor a missing value;pop()raisesIndexErrorfor an invalid position. Check membership or handle exceptions where appropriate.- Assuming every sequence operation modifies the original data or that a tuple makes nested mutable objects immutable.
Key Takeaways
- A list supports assignment by index, insertion before an index, and removal by value or position.
- The sequence becomes
email,backup,review; the insertion shifts later elements andremove()deletes the first matching value. remove()raisesValueErrorfor a missing value;pop()raisesIndexErrorfor an invalid position.