Effective Python: 59 Specific Ways to Write Better Python

Code Snippets......Page 0
Title Page......Page 2
Copyright Page......Page 3
Praise for Effective Python......Page 5
Dedication Page......Page 7
Contents......Page 8
What This Book Covers......Page 11
Conventions Used in This Book......Page 12
Where to Get the Code and Errata......Page 13
Acknowledgments......Page 14
About the Author......Page 15
Item 1: Know Which Version of Python You’re Using......Page 16
Item 2: Follow the PEP 8 Style Guide......Page 17
Item 3: Know the Differences Between bytes, str, and unicode......Page 19
Item 4: Write Helper Functions Instead of Complex Expressions......Page 22
Item 5: Know How to Slice Sequences......Page 24
Item 6: Avoid Using start, end, and stride in a Single Slice......Page 26
Item 7: Use List Comprehensions Instead of map and filter......Page 28
Item 8: Avoid More Than Two Expressions in List Comprehensions......Page 29
Item 9: Consider Generator Expressions for Large Comprehensions......Page 31
Item 10: Prefer enumerate Over range......Page 32
Item 11: Use zip to Process Iterators in Parallel......Page 34
Item 12: Avoid else Blocks After for and while Loops......Page 35
Item 13: Take Advantage of Each Block in try/except/else/finally......Page 38
Item 14: Prefer Exceptions to Returning None......Page 40
Item 15: Know How Closures Interact with Variable Scope......Page 42
Item 16: Consider Generators Instead of Returning Lists......Page 45
Item 17: Be Defensive When Iterating Over Arguments......Page 47
Item 18: Reduce Visual Noise with Variable Positional Arguments......Page 51
Item 19: Provide Optional Behavior with Keyword Arguments......Page 53
Item 20: Use None and Docstrings to Specify Dynamic Default Arguments......Page 56
Item 21: Enforce Clarity with Keyword-Only Arguments......Page 58
Item 22: Prefer Helper Classes Over Bookkeeping with Dictionaries and Tuples......Page 62
Item 23: Accept Functions for Simple Interfaces Instead of Classes......Page 67
Item 24: Use @classmethod Polymorphism to Construct Objects Generically......Page 70
Item 25: Initialize Parent Classes with super......Page 74
Item 26: Use Multiple Inheritance Only for Mix-in Utility Classes......Page 78
Item 27: Prefer Public Attributes Over Private Ones......Page 81
Item 28: Inherit from collections.abc for Custom Container Types......Page 86
Item 29: Use Plain Attributes Instead of Get and Set Methods......Page 90
Item 30: Consider @property Instead of Refactoring Attributes......Page 94
Item 31: Use Descriptors for Reusable @property Methods......Page 97
Item 32: Use __getattr__, __getattribute__, and __setattr__ for Lazy Attributes......Page 101
Item 33: Validate Subclasses with Metaclasses......Page 106
Item 34: Register Class Existence with Metaclasses......Page 108
Item 35: Annotate Class Attributes with Metaclasses......Page 112
Item 36: Use subprocess to Manage Child Processes......Page 115
Item 37: Use Threads for Blocking I/O, Avoid for Parallelism......Page 119
Item 38: Use Lock to Prevent Data Races in Threads......Page 122
Item 39: Use Queue to Coordinate Work Between Threads......Page 125
Item 40: Consider Coroutines to Run Many Functions Concurrently......Page 131
Item 41: Consider concurrent.futures for True Parallelism......Page 139
Item 42: Define Function Decorators with functools.wraps......Page 143
Item 43: Consider contextlib and with Statements for Reusable try/finally Behavior......Page 145
Item 44: Make pickle Reliable with copyreg......Page 148
Item 45: Use datetime Instead of time for Local Clocks......Page 153
Item 46: Use Built-in Algorithms and Data Structures......Page 157
Item 47: Use decimal When Precision Is Paramount......Page 161
Item 48: Know Where to Find Community-Built Modules......Page 163
Item 49: Write Docstrings for Every Function, Class, and Module......Page 165
Item 50: Use Packages to Organize Modules and Provide Stable APIs......Page 169
Item 51: Define a Root Exception to Insulate Callers from APIs......Page 173
Item 52: Know How to Break Circular Dependencies......Page 175
Item 53: Use Virtual Environments for Isolated and Reproducible Dependencies......Page 180
Item 54: Consider Module-Scoped Code to Configure Deployment Environments......Page 185
Item 55: Use repr Strings for Debugging Output......Page 187
Item 56: Test Everything with unittest......Page 189
Item 57: Consider Interactive Debugging with pdb......Page 192
Item 58: Profile Before Optimizing......Page 194
Item 59: Use tracemalloc to Understand Memory Usage and Leaks......Page 198
Index......Page 201