Python

Mutable Defaults in Python

PythonFunctionsArgumentsbeginner

What this snippet does

Default arguments are evaluated once at function definition; mutable defaults persist state across calls.

Expected output

[1]
[1, 2]

Why practise typing this

Typing functions code builds muscle memory for the symbols and indentation Python uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.

More Python practice

Browse all Python snippets →