Recipe 4.1. Copying an Object
Recipe 4.2. Constructing Lists with List Comprehensions
Recipe 4.3. Returning an Element of a List If It Exists
Recipe 4.4. Looping over Items and Their Indices in a Sequence
Recipe 4.5. Creating Lists of Lists Without Sharing References
Recipe 4.6. Flattening a Nested Sequence
Recipe 4.7. Removing or Reordering Columnsin a List of Rows
Recipe 4.8. Transposing Two-Dimensional Arrays
Recipe 4.9. Getting a Value from a Dictionary
Recipe 4.10. Adding an Entry to a Dictionary
Recipe 4.11. Building a Dictionary Without Excessive Quoting
Recipe 4.12. Building a Dict from a List of Alternating Keys and Values
Recipe 4.13. Extracting a Subset of a Dictionary
Recipe 4.14. Inverting a Dictionary
Recipe 4.15. Associating Multiple Values with Each Key in a Dictionary
Recipe 4.16. Using a Dictionary to Dispatch Methods or Functions
Recipe 4.17. Finding Unions and Intersections of Dictionaries
Recipe 4.18. Collecting a Bunch of Named Items
Recipe 4.19. Assigning and Testing with One Statement
Recipe 4.20. Using printf in Python
Recipe 4.21. Randomly Picking Items with Given Probabilities
Recipe 4.22. Handling Exceptions Within an Expression
Recipe 4.23. Ensuring a Name Is Defined in a Given Module