Python programs operate on objects with explicit input, ownership and failure contracts.
Learning roadmap
This section contains 6 written lessons or quiz banks. Programs are verified on CPython 3.14.6. Standard-library lessons target 3.11+ syntax; lessons using data, web, machine-learning or testing packages state their tested dependencies separately. Framework programs use local test clients, not a deployed service. Read the stated limits before adapting a fixture into an application.
Operation reminders
Read the contract, run its program and inspect the failure case.
Collection and failure operation reminders
Read the contract, run its program and inspect the failure case.
- Python collections reference: selection costs and retained ownership
- Python exceptions reference: raise, propagate, chain and clean up
Static claims versus runtime acceptance
Read the contract, run its program and inspect the failure case.
File and iteration reminders
Read the contract, run its program and inspect the failure case.
- Python pathlib reference: distinguish a path name from validated file content
- Python iterator reference: consume once or create a repeatable source
Continue learning
Move between tutorial, collections, advanced material and practice using the subject tabs. The sidebar changes with each section; related examples keep one canonical lesson URL.