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Pandas Coding for Data Tasks
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Pandas Coding for Data Tasks

MediumSQL · PostgreSQL

Problem

Pandas coding for a dataset

Using the supplied dataset, produce a category-level summary of usable observations. Include only observations with a valid status and a non-null value, while retaining categories that have no usable observations.

Output

  1. One row per category with category_name, observation_count, average_value, and maximum_value.
  2. Include categories with zero usable observations, with zero counts and null summary values.
  3. Order by observation_count descending, then category_name ascending.

Schema

categories
ColumnTypeDescription
category_idPKINTUnique category identifier
category_nameVARCHAR(100)Category label
observations
ColumnTypeDescription
observation_idPKINTUnique observation identifier
category_idINTReferenced category identifier
observed_atDATEObservation date
valueDECIMAL(10,2)Numeric observation value
statusVARCHAR(20)Observation quality status
Tablescategoriesobservations
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