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Data Analysis and Visualization with Python / Module 7

Module 7 check

Module 7 Assessment: Join Safety Check

Assessment ID: DAV-M07-QA01 Estimated active time: 30-40 minutes

Part A: Short answers

  1. When should you use concat?
  2. When should you use merge?
  3. What does a left join keep?
  4. Why can duplicate keys be dangerous?
  5. What should you record after a join?

Part B: Join plan

You have:

  • enrolments: one row per enrolment;
  • courses: one row per course;
  • support_tickets: one row per ticket.

Explain how you would create one row per enrolment with course details and ticket count.

Rubric

LevelEvidence
PassJoin plan checks keys, preserves row meaning, and reconciles row counts.
ReviseJoin plan is plausible but missing key checks or row-count evidence.
Not yetJoin plan merges tables without explaining keys, row meaning, or row counts.