Python for Data · Unit 2
Unit 2: Cleaning and Shaping
Fix missing values, wrong types and duplicate rows before you count anything.
Lessons
- What Dirty Data Looks LikeThe four problems you will meet in almost every real file.
- Missing ValuesFind them, then decide between dropping and filling on purpose.
- Fixing TypesEverything out of a file is text, and text sorts and adds in the wrong way.
- Removing DuplicatesDeciding what counts as the same row is most of the work.
- Filtering RowsSelecting the rows you meant, and noticing how many you dropped.
- Sorting and RankingOrder by the value you mean, and remember that sorted returns a new list.
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Take the Unit 2 test
End of unit test
Ten multiple choice questions and one free response problem. You need 70 to finish the unit. Retakes are unlimited and your best score is the one that counts.