Python

Phantom Keys in Python

PythonCollectionsDefaultdictintermediate

What this snippet does

Accessing a key in a defaultdict creates it, adding phantom keys if you just meant to check it.

Expected output

0
True

Why practise typing this

Typing collections 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.

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