What this snippet does
TypeVars allow writing functions that preserve the relationship between input and output types.
Expected output
1
Why practise typing this
Typing advanced typing 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
- Union TypesAdvanced Typing · intermediate
- Optional ReturnsAdvanced Typing · intermediate
- Pipe OperatorAdvanced Typing · intermediate
- Generic ClassAdvanced Typing · intermediate
- Runtime ErasureAdvanced Typing · intermediate
- Callable TypeAdvanced Typing · intermediate