Comprehensions, Iteration, and Pythonic Data Work Python lessons
Comprehensions, enumerate, zip, sorting keys, lambda, map/filter, and readable transformations.
5 exercises5+ conceptsBeginner → interview context
Start this topicWHAT YOU WILL LEARN
Core concepts
Sort records with a lambdaSquare values with mapFilter passing scoresMultiply values with reduceCreate a countdown iterator
REUSABLE THINKING
Problem-solving patterns
- lambda · sorting
- map · lambda
- filter · predicate
- reduce · operator
- iterator · StopIteration
LESSON OUTCOME
What this topic builds
Learn the idea once, trace it through two verified cases, then explain why your approach works.
ORDERED LESSONS
All 5 lessons in this topic
Work from top to bottom to build each concept gradually.
- #086Sort records with a lambdaBeginnerPremium
Sort competitors by score, highest first.
- #087Square values with mapIntermediatePremium
Square a short sequence of positive integers.
- #088Filter passing scoresIntermediatePremium
Keep all scores that meet a pass mark of 60.
- #089Multiply values with reduceIntermediatePremium
Multiply option counts to find the number of package combinations.
- #090Create a countdown iteratorAdvancedPremium
Iterate from three to zero using the iterator protocol.