university levels of education Python Lambda I — V
One subject taken all the way down, in five courses — handmade, no ads, no sign-ups. Twenty-five long lectures with runnable code throughout, two hundred and thirteen worked examples revealed step by step, three hundred and ninety-four practice problems with their solutions, quizzes for every lecture, and a hundred and three unsolved problems to do on your own, in nineteen ways of studying including a continuous read of a whole course. Start at whichever course you need; the last entry opens all five as one book.
- 001
Lambda I
Foundations: Expressions, Parameters, Logic and Sorting. Where lambda comes from and what it is — the mathematical function idea and Alonzo Church's lambda calculus; the one-expression rule and how a lambda differs from def; parameters in full, with defaults, star-args and keyword catch-alls; boolean logic and conditional expressions inside lambdas; then the single most common professional use of all, the key function that drives sorting, and map. Five deep lectures. Every lecture carries the full written explanation with runnable code throughout, a reference table of the forms that matter, defined terms, worked examples revealed step by step, practice problems with their solutions, a quiz, and unsolved problems to do on your own, studied through nineteen modes, from flashcards and drills to timed exams and a continuous read of the whole course as one page.
live - 002
Lambda II
The Functional Core: filter, reduce, Composition and Closures. Predicates and selection with filter; folding a sequence to one value with functools.reduce and its identity elements; composing small functions into pipelines and combinators; multi-key and mixed-direction sorting on real records; then closures — how a lambda remembers its birth scope, the late-binding trap that catches everyone, and the default-argument capture that fixes it. Five deep lectures. Every lecture carries the full written explanation with runnable code throughout, a reference table of the forms that matter, defined terms, worked examples revealed step by step, practice problems with their solutions, a quiz, and unsolved problems to do on your own, studied through nineteen modes, from flashcards and drills to timed exams and a continuous read of the whole course as one page.
live - 003
Lambda III
Design and Application: Currying, Laziness, Patterns, Callbacks and Files. Currying and partial application for configurable APIs; iterators, generators and itertools for lazy pipelines over unbounded data; the pattern layer of pure functions, dispatch tables, strategies and dependency injection; callbacks and event-driven code where the loop-variable trap returns in GUI form; and real file work, from CSV and JSON cleaning to full ETL pipelines. Five deep lectures. Every lecture carries the full written explanation with runnable code throughout, a reference table of the forms that matter, defined terms, worked examples revealed step by step, practice problems with their solutions, a quiz, and unsolved problems to do on your own, studied through nineteen modes, from flashcards and drills to timed exams and a continuous read of the whole course as one page.
live - 004
Lambda IV
Data and Science: NumPy, pandas, Machine Learning and Algorithms. Where lambdas meet the numerical stack, including when NOT to use them — vectorisation in NumPy against element-wise mapping; pandas apply, map and groupby aggregation; feature engineering, loss functions and scikit-learn pipelines with their pickling caveat; memoisation, functors and monadic patterns; and lambdas inside algorithms, from heaps and greedy choices to graph work. Five deep lectures. Every lecture carries the full written explanation with runnable code throughout, a reference table of the forms that matter, defined terms, worked examples revealed step by step, practice problems with their solutions, a quiz, and unsolved problems to do on your own, studied through nineteen modes, from flashcards and drills to timed exams and a continuous read of the whole course as one page.
live - 005
Lambda V
Professional Practice: Style, Concurrency, Testing and the Capstone. When a lambda is right and when PEP 8 demands a def; concurrency with thread and process pools, and the pickling rule that decides which one may take a lambda; testing, debugging, profiling and typing functional code; the advanced patterns — functors, monads, Result values and trampolines; and a capstone that reassembles the entire course into working pipelines. Five deep lectures. Every lecture carries the full written explanation with runnable code throughout, a reference table of the forms that matter, defined terms, worked examples revealed step by step, practice problems with their solutions, a quiz, and unsolved problems to do on your own, studied through nineteen modes, from flashcards and drills to timed exams and a continuous read of the whole course as one page.
live - 006
The whole of lambda
All five courses opened as one book — twenty-five deep lectures from the one-expression rule to functional architecture in production, with 760 questions between them, readable end to end in the continuous view or studied through any of the nineteen modes across the whole sequence at once.
live