Pydon'ts – Write elegant Python code

Description

Would you like me to teach you how to write Python ? code that is more elegant, more effective, and more expressive than what you have been writing until now... for free? I am looking to teach Python to people who want to master Python to the best of their abilities. Do you? If you do, then I know I can help you improve your skills. Python has dozens of built-ins, and all of them have multiple usage patterns. No human knows all of them by heart, but my research bundled them up nicely in a book for you to reference and learn from. With the help of the +20 chapters and +260 pages of this book, you will learn more about all the built-ins and their usage patterns, and your code will become more elegant, it will become more effective, and it will also become more expressive. Foreword Pydon’t disrespect the Zen of Python Zen of Python References Does elegance matter? Introduction Beware, opinions ahead Elegance is not a dispensable luxury Don’t write that, that’s unreadable The right tool for the job Optimise for rewrite Conclusion References Code style matters Introduction Code style Tools for your tool belt Conclusion References Naming matters Introduction Naming conventions PEP 8 recommendations Standard names Verbosity Picking a name Context is key Practical example Conclusion References Chaining comparison operators Introduction Chaining of comparison operators Pitfalls Ugly chains Examples in code Conclusion References Assignment expressions and the walrus operator := Walrus operator and assignment expressions Examples in code Conclusion References Truthy, Falsy, and bool “Truthy” and “Falsy” The __bool__ dunder method Remarks Examples in code Conclusion References Deep unpacking Introduction Assignments Examples in code Conclusion References Unpacking with starred assignments Starred Assignment Examples in code References EAFP and LBYL coding styles EAFP and LBYL EAFP instead of LBYL? Conclusion References Zip up Introduction How zip works Zip is lazy Three is a crowd Mismatched lengths Create a dictionary with zip Examples in code Conclusion References Enumerate me Introduction How enumerate works Optional start argument Unpacking when iterating Examples in code Conclusion References str and repr str and repr The __str__ and __repr__ dunder methods Examples in code Conclusion References Structural pattern matching tutorial Introduction Structural pattern matching Python could already do Your first match statement Pattern matching the basic structure Matching the structure of objects __match_args__ Wildcards Naming sub-patterns Traversing recursive structures Conclusion References Structural pattern matching anti-patterns Introduction There should be only one obvious way to do it A short and sweet if statement Be smart(er) Basic mappings Conclusion References Watch out for recursion Introduction Watch out for recursion Examples in code Conclusion References Sequence indexing Introduction Sequence indexing Maximum legal index and index errors Negative indices Indexing idioms To index or not to index? Best practices in code Conclusion Idiomatic sequence slicing Introduction Slicing syntax What to slice? Slicing from the beginning Slicing until the end Slicing with negative indices Slicing and range Idiomatic slicing patterns Empty slices More empty slices Examples in code Conclusion References Mastering sequence slicing Introduction Slicing step Sequence copying Manipulating mutable sequences More idiomatic slicing Conclusion References Inner workings of sequence slicing Introduction The slice class Getting items from sequences Setting items, deleting items, and container emulation Comma-separated indices and slices Examples in code Conclusion References Boolean short-circuiting Introduction Return values of the and and or operators Short-circuiting Short-circuiting in plain English all and any Short-circuiting in chained comparisons Examples in code Conclusion References The power of reduce Introduction How reduce works The rabbit hole of the built-in reductions Why bother? Far-fetched reductions The identity element… Why some people dislike reduce Examples in code Conclusion References Usages of underscore Introduction Recovering last result in the session Prefixes and suffixes for variable names Underscore as a sink Matching everything in the new match statement String localisation Improve number readability Conclusion References name dunder attribute Introduction What is __name__? The module attribute __name__ __name__ as an object type attribute Examples in code Conclusion References Bite-sized refactoring Introduction Refactoring What to refactor? Case study Conclusion References String translate and maketrans methods Introduction str.translate Non-equivalence to str.replace Generic translation tables str.maketrans Examples in code Conclusion References Boost your productivity with the REPL Introduction REPL Just fire up the REPL REPL mechanics The last result Getting help from within the REPL Tips for quick hacks Other tools Conclusion References set and frozenset Introduction (Mathematical) sets (Common) Operations on sets Differences between set and frozenset What are sets used for? Examples in code Conclusion References List comprehensions 101 Introduction What is a list comprehension? Anatomy of a list comprehension Example list comprehensions without filtering Example list comprehensions with filtering Equivalence with for loops Nesting for loops Nesting if statements Arbitrary nesting List comprehensions instead of map and filter Examples in code Conclusion References Conditional expressions Introduction What is a conditional expression? Rationale Short-circuiting Conditional expressions and if statements Precedence Conditional expressions that evaluate to Booleans Examples in code Conclusion References Pass-by-value, reference, and assignment Introduction Is Python pass-by-value? Is Python pass-by-reference? Python object model Python is pass-by-assignment Making copies Examples in code Conclusion References String formatting comparison Introduction String formatting rationale Three string formatting methods Value conversion Alignment Named placeholders Accessing nested data structures Parametrised formatting Custom formatting Examples in code Conclusion References Closing thoughts