Dataford
Interview QuestionsInterview GuidesExperiencesCoaching
New
Pricing
Get started
Dataford
Popular roles
Software EngineerData AnalystData ScientistData EngineerBusiness AnalystAI EngineerMachine Learning EngineerProduct Manager
Browse
Browse All RolesEvery role hub, from analyst to MLBrowse All CompaniesCompany-specific interview loopsAll Interview GuidesThe full guide library
Top questions by role
Software EngineerData AnalystData ScientistData EngineerBusiness AnalystAI EngineerMachine Learning EngineerProduct Manager
Top questions by skill
SQLPythonStatisticsMachine LearningA/B TestingSystem DesignGenerative AIProduct SenseMetricsBehavioral
Browse all questions →Try a mock interview
Experiences
Practice
Mock InterviewsTimed interview simulations with feedbackCoaching1:1 coaching with people at your target companiesSuccess PathYour 6-week structured planModulesCurated lessons by topicWebinarsTalks from ex-Big Tech data leadsPlaygroundA free-form scratch editor
Learn
BlogInterview strategy and career adviceTech Job Market ReportHiring trends across data and AI rolesFor UniversitiesDataford for career centersAbout DatafordWho we are and how we build
Pricing
Build my plan
Pandas Data Cleaning Pipeline
00:00
5 left

Pandas Data Cleaning Pipeline

MediumSQL · PostgreSQL

Problem

Given a raw dataset in Python, write a script using Pandas to handle missing data, normalize numerical features, and export the cleaned data.

For this SQL version, return an export-ready result from raw_dataset. Replace missing numerical values with the median of their respective columns, then scale each numerical feature to the 0 to 1 range.

Output

  1. One row per input record with record_id, source_label, and cleaned normalized values named age_normalized, annual_income_normalized, and engagement_score_normalized.
  2. Include every input record and order by record_id ascending.

Schema

raw_dataset
ColumnTypeDescription
record_idPKINTUnique input record identifier
source_labelVARCHAR(50)Source label associated with the record
ageINTAge value requiring cleaning and normalization
annual_incomeDECIMAL(12,2)Annual income value requiring cleaning and normalization
engagement_scoreDECIMAL(5,2)Numerical engagement score requiring cleaning and normalization
Tablesraw_dataset
Interviewer

Your question is Pandas Data Cleaning Pipeline. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

You need to log in / sign up to run or submit.
CodePostgreSQL
Sign up free to run your codeLog inLn 1
Run your query to see results here.