A little more Python.
A little more confidence.

1. 01

   Your first Python program

   Beginner

   Run a few statements and follow how named values reach printed output.

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   Open chapter: Your first Python program
2. 02

   Working with strings

   Beginner

   Read, slice, and clean text with explicit rules for spaces and separators.

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   Open chapter: Working with strings
3. 03

   Lists and changing one item

   Beginner

   Build an ordered collection and use indexes to inspect or update it.

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   Open chapter: Lists and changing one item
4. 04

   Decisions and repeating work

   Beginner

   Choose a branch and process a small list using indentation and a for loop.

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   Open chapter: Decisions and repeating work
5. 05

   Functions that return an answer

   Beginner

   Give a reusable calculation a name, inputs, and a returned result.

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   Open chapter: Functions that return an answer
6. 06

   Values, text, and arithmetic

   Beginner

   Choose operations that match the meaning of the data.

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   Open chapter: Values, text, and arithmetic
7. 07

   Functions and dependable defaults

   Beginner

   Define return contracts and avoid shared default state.

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   Open chapter: Functions and dependable defaults
8. 08

   Lists, sets, and dictionaries

   Intermediate

   Select a collection from its required behavior.

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   Open chapter: Lists, sets, and dictionaries
9. 09

   Comprehensions and nested aliasing

   Intermediate

   Express transformations without creating shared mutable rows.

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   Open chapter: Comprehensions and nested aliasing
10. 10

    Lexical scope and closures

    Intermediate

    Track which binding a nested function reads or changes.

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    Open chapter: Lexical scope and closures
11. 11

    Iterators and lazy pipelines

    Intermediate

    Process sequences incrementally with explicit consumption.

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    Open chapter: Iterators and lazy pipelines
12. 12

    Instance state and behavioral contracts

    Intermediate

    Protect object invariants and avoid shared class-level collections.

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    Open chapter: Instance state and behavioral contracts
13. 13

    Exceptions and resource boundaries

    Advanced

    Handle expected failures without hiding programming defects.

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    Open chapter: Exceptions and resource boundaries
14. 14

    JSON parsing and domain validation

    Advanced

    Separate syntactic parsing from application rules.

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    Open chapter: JSON parsing and domain validation
15. 15

    Records, ordering, and invariants

    Advanced

    Model data explicitly and reason about repeatable ordering.

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    Open chapter: Records, ordering, and invariants
16. 16

    Modules and tests that challenge a contract

    Intermediate

    Make reusable code importable and choose tests that expose defects.

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    Open chapter: Modules and tests that challenge a contract
17. 17

    Recursive algorithms and terminating ranges

    Advanced

    Use shrinking subproblems and explicit base cases.

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    Open chapter: Recursive algorithms and terminating ranges

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