Python pattern

Missing data

4 problems in this pattern, climbing easy → medium → hard. Pick wherever you're calibrated.

Easy

0 / 1 solved

Coalesce a column from a fallback
Python · ~8 min
NEW

Medium

0 / 2 solved

Hard

0 / 1 solved

Daily store report: zero-fill the sales, forward-fill the stock (but not forever)
Python · ~22 min
NEW