Python list.append Method: Usage and Examples

A packing checklist gains one new task.

What You Need to Understand

list.append(item) adds one object to the end of a list. If that object is itself a list, it is added as a single nested element.

When to Use It

A packing checklist gains one new task.

Step-by-Step Python Example

tasks = ["pack", "label"]
result = tasks.append("ship")
print(tasks)
print(result)

How the Example Works

The list now has three entries, and the method returned None because it changed the list in place.

Example Output

['pack', 'label', 'ship']
None
['core', ['extra', 'optional']]

A Second Example

Compare this smaller variation with the main example, then experiment with your own values.

groups = ["core"]
groups.append(["extra", "optional"])
print(groups)

Important Behavior and Edge Cases

Do not assign tasks = tasks.append("ship"): that replaces your list variable with None.

Try It Yourself

Append a list of two tags to a list and inspect whether it creates one nested item.

Common Beginner Mistakes

• Do not assign tasks = tasks.append("ship"): that replaces your list variable with None.
• Using the wrong collection method for this operation without checking whether it mutates the object, returns a result, or raises on missing data.

Key Takeaways

• list.append(item) adds one object to the end of a list.
• The list now has three entries, and the method returned None because it changed the list in place.
• Do not assign tasks = tasks.append("ship"): that replaces your list variable with None.