How to Make Mistakes in Python

Table of contents

1. Introduction
2. 1. Setup
   1. Polluting the System Python
   2. Using the Default REPL
3. 2. Silly Things
   1. Forgetting to Return a Value
   2. Misspellings
   3. Mixing Up Def and Class
4. 3. Style
   1. Hungarian Notation
   2. PEP-8 Violations
   3. Bad Naming
   4. Inscrutable Lambdas
   5. Incomprehensible Comprehensions
5. 4. Structure
   1. Pathological If/Elif Blocks
   2. Unnecessary Getters and Setters
   3. Getting Wrapped Up in Decorators
   4. Breaking the Law of Demeter
   5. Overusing Private Attributes
   6. God Objects and God Methods
   7. Global State
6. 5. Surprises
   1. Importing Everything
   2. Overbroadly Silencing Exceptions
   3. Reinventing the Wheel
   4. Mutable Keyword Argument Defaults
   5. Overeager Code
      1. At Import Time
      2. At Instantiation Time
   6. Poisoning Persistent State
   7. Assuming Logging Is Unnecessary
      1. Log at Boundaries
      2. Log Actions, Motives, and Results
      3. Log Mindfully
   8. Assuming Tests Are Unnecessary
7. 6. Further Resources
   1. Philosophy
   2. Tools