Problem 1 of 5 · Data-shape transformsNext: Pivot a long metrics table to wide

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Practice / Python / Data-shape transforms

WorkingGuided

EasyAbout 10 minData-shape transforms

Reshape long records into a wide nested dict

Given a list of "long" records {"row": str, "col": str, "val": any}, reshape into a nested dict mapping row -> {col -> val}.

If the same (row, col) appears more than once, the later record wins. Empty input returns {}.

What the tests check

4 on Run · 5 on Submit

01empty input

02single record

03multiple columns under one row

04multiple rows

Submit runs these and one more check you don’t see, so code written for the visible tests alone can still miss.

Runtime

Python 3.13 in your browser – the standard library plus pandas and numpy; no pip installs.

If you get stuck

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