• Table of Contents
• Reviews
• Reader Reviews
• Errata
• Academic

Python Cookbook, 2nd Edition
By David Ascher, Alex Martelli, Anna Ravenscroft
Publisher	: O'Reilly
Pub Date	: March 2005
ISBN	: 0-596-00797-3
Pages	: 844

		Copyright
		Preface
			The Design of the Book
			The Implementation of the Book
			Using the Code from This Book
			Audience
			Organization
			Further Reading
			Conventions Used in This Book
			How to Contact Us
			Safari® Enabled
			Acknowledgments
		Chapter 1. Text
			Introduction
			Recipe 1.1. Processing a String One Character at a Time
			Recipe 1.2. Converting Between Characters and Numeric Codes
			Recipe 1.3. Testing Whether an Object Is String-like
			Recipe 1.4. Aligning Strings
			Recipe 1.5. Trimming Space from the Ends of a String
			Recipe 1.6. Combining Strings
			Recipe 1.7. Reversing a String by Words or Characters
			Recipe 1.8. Checking Whether a String Contains a Set of Characters
			Recipe 1.9. Simplifying Usage of Strings' translate Method
			Recipe 1.10. Filtering a String for a Set of Characters
			Recipe 1.11. Checking Whether a String Is Text or Binary
			Recipe 1.12. Controlling Case
			Recipe 1.13. Accessing Substrings
			Recipe 1.14. Changing the Indentation of a Multiline String
			Recipe 1.15. Expanding and Compressing Tabs
			Recipe 1.16. Interpolating Variables in a String
			Recipe 1.17. Interpolating Variables in a Stringin Python 2.4
			Recipe 1.18. Replacing Multiple Patterns in a Single Pass
			Recipe 1.19. Checking a String for Any of Multiple Endings
			Recipe 1.20. Handling International Text with Unicode
			Recipe 1.21. Converting Between Unicode and Plain Strings
			Recipe 1.22. Printing Unicode Charactersto Standard Output
			Recipe 1.23. Encoding Unicode Data for XML and HTML
			Recipe 1.24. Making Some Strings Case-Insensitive
			Recipe 1.25. Converting HTML Documents to Texton a Unix Terminal
		Chapter 2. Files
			Introduction
			Recipe 2.1. Reading from a File
			Recipe 2.2. Writing to a File
			Recipe 2.3. Searching and Replacing Text in a File
			Recipe 2.4. Reading a Specific Line from a File
			Recipe 2.5. Counting Lines in a File
			Recipe 2.6. Processing Every Word in a File
			Recipe 2.7. Using Random-Access Input/Output
			Recipe 2.8. Updating a Random-Access File
			Recipe 2.9. Reading Data from zip Files
			Recipe 2.10. Handling a zip File Inside a String
			Recipe 2.11. Archiving a Tree of Files into a Compressed tar File
			Recipe 2.12. Sending Binary Data to Standard Output Under Windows
			Recipe 2.13. Using a C++-like iostream Syntax
			Recipe 2.14. Rewinding an Input File to the Beginning
			Recipe 2.15. Adapting a File-like Object to a True File Object
			Recipe 2.16. Walking Directory Trees
			Recipe 2.17. Swapping One File Extension for Another Throughout a Directory Tree
			Recipe 2.18. Finding a File Given a Search Path
			Recipe 2.19. Finding Files Given a Search Path and a Pattern
			Recipe 2.20. Finding a File on the Python Search Path
			Recipe 2.21. Dynamically Changing the PythonSearch Path
			Recipe 2.22. Computing the Relative Path from One Directory to Another
			Recipe 2.23. Reading an Unbuffered Character in a Cross-Platform Way
			Recipe 2.24. Counting Pages of PDF Documents on Mac OS X
			Recipe 2.25. Changing File Attributes on Windows
			Recipe 2.26. Extracting Text from OpenOffice.org Documents
			Recipe 2.27. Extracting Text from Microsoft Word Documents
			Recipe 2.28. File Locking Using a Cross-Platform API
			Recipe 2.29. Versioning Filenames
			Recipe 2.30. Calculating CRC-64 Cyclic Redundancy Checks
		Chapter 3. Time and Money
			Introduction
			Recipe 3.1. Calculating Yesterday and Tomorrow
			Recipe 3.2. Finding Last Friday
			Recipe 3.3. Calculating Time Periods in a Date Range
			Recipe 3.4. Summing Durations of Songs
			Recipe 3.5. Calculating the Number of Weekdays Between Two Dates
			Recipe 3.6. Looking up Holidays Automatically
			Recipe 3.7. Fuzzy Parsing of Dates
			Recipe 3.8. Checking Whether Daylight Saving Time Is Currently in Effect
			Recipe 3.9. Converting Time Zones
			Recipe 3.10. Running a Command Repeatedly
			Recipe 3.11. Scheduling Commands
			Recipe 3.12. Doing Decimal Arithmetic
			Recipe 3.13. Formatting Decimals as Currency
			Recipe 3.14. Using Python as a Simple Adding Machine
			Recipe 3.15. Checking a Credit Card Checksum
			Recipe 3.16. Watching Foreign Exchange Rates
		Chapter 4. Python Shortcuts
			Introduction
			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
		Chapter 5. Searching and Sorting
			Introduction
			Recipe 5.1. Sorting a Dictionary
			Recipe 5.2. Sorting a List of Strings Case-Insensitively
			Recipe 5.3. Sorting a List of Objects by an Attribute of the Objects
			Recipe 5.4. Sorting Keys or Indices Basedon the Corresponding Values
			Recipe 5.5. Sorting Strings with Embedded Numbers
			Recipe 5.6. Processing All of a List's Items in Random Order
			Recipe 5.7. Keeping a Sequence Ordered as Items Are Added
			Recipe 5.8. Getting the First Few Smallest Items of a Sequence
			Recipe 5.9. Looking for Items in a Sorted Sequence
			Recipe 5.10. Selecting the nth Smallest Element of a Sequence
			Recipe 5.11. Showing off quicksort in Three Lines
			Recipe 5.12. Performing Frequent Membership Tests on a Sequence
			Recipe 5.13. Finding Subsequences
			Recipe 5.14. Enriching the Dictionary Type with Ratings Functionality
			Recipe 5.15. Sorting Names and Separating Them by Initials
		Chapter 6. Object-Oriented Programming
			Introduction
			Recipe 6.1. Converting Among Temperature Scales
			Recipe 6.2. Defining Constants
			Recipe 6.3. Restricting Attribute Setting
			Recipe 6.4. Chaining Dictionary Lookups
			Recipe 6.5. Delegating Automatically as an Alternative to Inheritance
			Recipe 6.6. Delegating Special Methods in Proxies
			Recipe 6.7. Implementing Tuples with Named Items
			Recipe 6.8. Avoiding Boilerplate Accessors for Properties
			Recipe 6.9. Making a Fast Copy of an Object
			Recipe 6.10. Keeping References to Bound Methods Without Inhibiting Garbage Collection
			Recipe 6.11. Implementing a Ring Buffer
			Recipe 6.12. Checking an Instance for Any State Changes
			Recipe 6.13. Checking Whether an Object Has Necessary Attributes
			Recipe 6.14. Implementing the State Design Pattern
			Recipe 6.15. Implementing the "Singleton" Design Pattern
			Recipe 6.16. Avoiding the "Singleton" Design Pattern with the Borg Idiom
			Recipe 6.17. Implementing the Null Object Design Pattern
			Recipe 6.18. Automatically Initializing Instance Variables from _ _init_ _ Arguments
			Recipe 6.19. Calling a Superclass _ _init_ _ Method If It Exists
			Recipe 6.20. Using Cooperative Supercalls Concisely and Safely
		Chapter 7. Persistence and Databases
			Introduction
			Recipe 7.1. Serializing Data Using the marshal Module
			Recipe 7.2. Serializing Data Using the pickle and cPickle Modules
			Recipe 7.3. Using Compression with Pickling
			Recipe 7.4. Using the cPickle Module on Classes and Instances
			Recipe 7.5. Holding Bound Methods in a Picklable Way
			Recipe 7.6. Pickling Code Objects
			Recipe 7.7. Mutating Objects with shelve
			Recipe 7.8. Using the Berkeley DB Database
			Recipe 7.9. Accesssing a MySQL Database
			Recipe 7.10. Storing a BLOB in a MySQL Database
			Recipe 7.11. Storing a BLOB in a PostgreSQL Database
			Recipe 7.12. Storing a BLOB in a SQLite Database
			Recipe 7.13. Generating a Dictionary Mapping Field Names to Column Numbers
			Recipe 7.14. Using dtuple for Flexible Accessto Query Results
			Recipe 7.15. Pretty-Printing the Contents of Database Cursors
			Recipe 7.16. Using a Single Parameter-Passing Style Across Various DB API Modules
			Recipe 7.17. Using Microsoft Jet via ADO
			Recipe 7.18. Accessing a JDBC Database from a Jython Servlet
			Recipe 7.19. Using ODBC to Get Excel Data with Jython
		Chapter 8. Debugging and Testing
			Introduction
			Recipe 8.1. Disabling Execution of Some Conditionals and Loops
			Recipe 8.2. Measuring Memory Usage on Linux
			Recipe 8.3. Debugging the Garbage-Collection Process
			Recipe 8.4. Trapping and Recording Exceptions
			Recipe 8.5. Tracing Expressions and Comments in Debug Mode
			Recipe 8.6. Getting More Information from Tracebacks
			Recipe 8.7. Starting the Debugger Automatically After an Uncaught Exception
			Recipe 8.8. Running Unit Tests Most Simply
			Recipe 8.9. Running Unit Tests Automatically
			Recipe 8.10. Using doctest with unittest in Python 2.4
			Recipe 8.11. Checking Values Against Intervals in Unit Testing
		Chapter 9. Processes, Threads, and Synchronization
			Introduction
			Recipe 9.1. Synchronizing All Methods in an Object
			Recipe 9.2. Terminating a Thread
			Recipe 9.3. Using a Queue.Queue as a Priority Queue
			Recipe 9.4. Working with a Thread Pool
			Recipe 9.5. Executing a Function in Parallel on Multiple Argument Sets
			Recipe 9.6. Coordinating Threads by Simple Message Passing
			Recipe 9.7. Storing Per-Thread Information
			Recipe 9.8. Multitasking Cooperatively Without Threads
			Recipe 9.9. Determining Whether Another Instanceof a Script Is Already Running in Windows
			Recipe 9.10. Processing Windows Messages Using MsgWaitForMultipleObjects
			Recipe 9.11. Driving an External Process with popen
			Recipe 9.12. Capturing the Output and Error Streams from a Unix Shell Command
			Recipe 9.13. Forking a Daemon Process on Unix
		Chapter 10. System Administration
			Introduction
			Recipe 10.1. Generating Random Passwords
			Recipe 10.2. Generating Easily Remembered Somewhat-Random Passwords
			Recipe 10.3. Authenticating Users by Means of a POP Server
			Recipe 10.4. Calculating Apache Hits per IP Address
			Recipe 10.5. Calculating the Rate of Client Cache Hits on Apache
			Recipe 10.6. Spawning an Editor from a Script
			Recipe 10.7. Backing Up Files
			Recipe 10.8. Selectively Copying a Mailbox File
			Recipe 10.9. Building a Whitelist of Email Addresses From a Mailbox
			Recipe 10.10. Blocking Duplicate Mails
			Recipe 10.11. Checking Your Windows Sound System
			Recipe 10.12. Registering or Unregistering a DLL on Windows
			Recipe 10.13. Checking and Modifying the Set of Tasks Windows Automatically Runs at Login
			Recipe 10.14. Creating a Share on Windows
			Recipe 10.15. Connecting to an Already Running Instance of Internet Explorer
			Recipe 10.16. Reading Microsoft Outlook Contacts
			Recipe 10.17. Gathering Detailed System Informationon Mac OS X
		Chapter 11. User Interfaces
			Introduction
			Recipe 11.1. Showing a Progress Indicator on a Text Console
			Recipe 11.2. Avoiding lambda in Writing Callback Functions
			Recipe 11.3. Using Default Values and Bounds with tkSimpleDialog Functions
			Recipe 11.4. Adding Drag and Drop Reordering to a Tkinter Listbox
			Recipe 11.5. Entering Accented Characters in Tkinter Widgets
			Recipe 11.6. Embedding Inline GIFs Using Tkinter
			Recipe 11.7. Converting Among Image Formats
			Recipe 11.8. Implementing a Stopwatch in Tkinter
			Recipe 11.9. Combining GUIs and Asynchronous I/Owith Threads
			Recipe 11.10. Using IDLE's Tree Widget in Tkinter
			Recipe 11.11. Supporting Multiple Values per Row in a Tkinter Listbox
			Recipe 11.12. Copying Geometry Methods and Options Between Tkinter Widgets
			Recipe 11.13. Implementing a Tabbed Notebook for Tkinter
			Recipe 11.14. Using a wxPython Notebook with Panels
			Recipe 11.15. Implementing an ImageJ Plug-in in Jython
			Recipe 11.16. Viewing an Image from a URL with Swing and Jython
			Recipe 11.17. Getting User Input on Mac OS
			Recipe 11.18. Building a Python Cocoa GUI Programmatically
			Recipe 11.19. Implementing Fade-in Windows with IronPython
		Chapter 12. Processing XML
			Introduction
			Recipe 12.1. Checking XML Well-Formedness
			Recipe 12.2. Counting Tags in a Document
			Recipe 12.3. Extracting Text from an XML Document
			Recipe 12.4. Autodetecting XML Encoding
			Recipe 12.5. Converting an XML Document into a Tree of Python Objects
			Recipe 12.6. Removing Whitespace-only Text Nodes from an XML DOM Node's Subtree
			Recipe 12.7. Parsing Microsoft Excel's XML
			Recipe 12.8. Validating XML Documents
			Recipe 12.9. Filtering Elements and Attributes Belonging to a Given Namespace
			Recipe 12.10. Merging Continuous Text Events with a SAX Filter
			Recipe 12.11. Using MSHTML to Parse XML or HTML
		Chapter 13. Network Programming
			Introduction
			Recipe 13.1. Passing Messages with Socket Datagrams
			Recipe 13.2. Grabbing a Document from the Web
			Recipe 13.3. Filtering a List of FTP Sites
			Recipe 13.4. Getting Time from a Server via the SNTP Protocol
			Recipe 13.5. Sending HTML Mail
			Recipe 13.6. Bundling Files in a MIME Message
			Recipe 13.7. Unpacking a Multipart MIME Message
			Recipe 13.8. Removing Attachments from an Email Message
			Recipe 13.9. Fixing Messages Parsed by Python 2.4 email.FeedParser
			Recipe 13.10. Inspecting a POP3 Mailbox Interactively
			Recipe 13.11. Detecting Inactive Computers
			Recipe 13.12. Monitoring a Network with HTTP
			Recipe 13.13. Forwarding and Redirecting Network Ports
			Recipe 13.14. Tunneling SSL Through a Proxy
			Recipe 13.15. Implementing the Dynamic IP Protocol
			Recipe 13.16. Connecting to IRC and Logging Messages to Disk
			Recipe 13.17. Accessing LDAP Servers
		Chapter 14. Web Programming
			Introduction
			Recipe 14.1. Testing Whether CGI Is Working
			Recipe 14.2. Handling URLs Within a CGI Script
			Recipe 14.3. Uploading Files with CGI
			Recipe 14.4. Checking for a Web Page's Existence
			Recipe 14.5. Checking Content Type via HTTP
			Recipe 14.6. Resuming the HTTP Download of a File
			Recipe 14.7. Handling Cookies While Fetching Web Pages
			Recipe 14.8. Authenticating with a Proxy for HTTPS Navigation
			Recipe 14.9. Running a Servlet with Jython
			Recipe 14.10. Finding an Internet Explorer Cookie
			Recipe 14.11. Generating OPML Files
			Recipe 14.12. Aggregating RSS Feeds
			Recipe 14.13. Turning Data into Web Pages Through Templates
			Recipe 14.14. Rendering Arbitrary Objects with Nevow
		Chapter 15. Distributed Programming
			Introduction
			Recipe 15.1. Making an XML-RPC Method Call
			Recipe 15.2. Serving XML-RPC Requests
			Recipe 15.3. Using XML-RPC with Medusa
			Recipe 15.4. Enabling an XML-RPC Server to Be Terminated Remotely
			Recipe 15.5. Implementing SimpleXMLRPCServer Niceties
			Recipe 15.6. Giving an XML-RPC Server a wxPython GUI
			Recipe 15.7. Using Twisted Perspective Broker
			Recipe 15.8. Implementing a CORBA Server and Client
			Recipe 15.9. Performing Remote Logins Using telnetlib
			Recipe 15.10. Performing Remote Logins with SSH
			Recipe 15.11. Authenticating an SSL Client over HTTPS
		Chapter 16. Programs About Programs
			Introduction
			Recipe 16.1. Verifying Whether a String Represents a Valid Number
			Recipe 16.2. Importing a Dynamically Generated Module
			Recipe 16.3. Importing from a Module Whose Name Is Determined at Runtime
			Recipe 16.4. Associating Parameters with a Function (Currying)
			Recipe 16.5. Composing Functions
			Recipe 16.6. Colorizing Python Source Using the Built-in Tokenizer
			Recipe 16.7. Merging and Splitting Tokens
			Recipe 16.8. Checking Whether a String Has Balanced Parentheses
			Recipe 16.9. Simulating Enumerations in Python
			Recipe 16.10. Referring to a List Comprehension While Building It
			Recipe 16.11. Automating the py2exe Compilation of Scripts into Windows Executables
			Recipe 16.12. Binding Main Script and Modules into One Executable on Unix
		Chapter 17. Extending and Embedding
			Introduction
			Recipe 17.1. Implementing a Simple Extension Type
			Recipe 17.2. Implementing a Simple Extension Type with Pyrex
			Recipe 17.3. Exposing a C++ Library to Python
			Recipe 17.4. Calling Functions from a Windows DLL
			Recipe 17.5. Using SWIG-Generated Modules in a Multithreaded Environment
			Recipe 17.6. Translating a Python Sequence into a C Array with the PySequence_Fast Protocol
			Recipe 17.7. Accessing a Python Sequence Item-by-Item with the Iterator Protocol
			Recipe 17.8. Returning None from a Python-Callable C Function
			Recipe 17.9. Debugging Dynamically Loaded C Extensions with gdb
			Recipe 17.10. Debugging Memory Problems
		Chapter 18. Algorithms
			Introduction
			Recipe 18.1. Removing Duplicates from a Sequence
			Recipe 18.2. Removing Duplicates from a Sequence While Maintaining Sequence Order
			Recipe 18.3. Generating Random Samples with Replacement
			Recipe 18.4. Generating Random Samples Without Replacement
			Recipe 18.5. Memoizing (Caching) the Return Values of Functions
			Recipe 18.6. Implementing a FIFO Container
			Recipe 18.7. Caching Objects with a FIFO Pruning Strategy
			Recipe 18.8. Implementing a Bag (Multiset) Collection Type
			Recipe 18.9. Simulating the Ternary Operator in Python
			Recipe 18.10. Computing Prime Numbers
			Recipe 18.11. Formatting Integers as Binary Strings
			Recipe 18.12. Formatting Integers as Strings in Arbitrary Bases
			Recipe 18.13. Converting Numbers to Rationals via Farey Fractions
			Recipe 18.14. Doing Arithmetic with Error Propagation
			Recipe 18.15. Summing Numbers with Maximal Accuracy
			Recipe 18.16. Simulating Floating Point
			Recipe 18.17. Computing the Convex Hulls and Diameters of 2D Point Sets
		Chapter 19. Iterators and Generators
			Introduction
			Recipe 19.1. Writing a range-like Function with Float Increments
			Recipe 19.2. Building a List from Any Iterable
			Recipe 19.3. Generating the Fibonacci Sequence
			Recipe 19.4. Unpacking a Few Items in a Multiple Assignment
			Recipe 19.5. Automatically Unpacking the Needed Number of Items
			Recipe 19.6. Dividing an Iterable into n Slices of Stride n
			Recipe 19.7. Looping on a Sequence by Overlapping Windows
			Recipe 19.8. Looping Through Multiple Iterables in Parallel
			Recipe 19.9. Looping Through the Cross-Product of Multiple Iterables
			Recipe 19.10. Reading a Text File by Paragraphs
			Recipe 19.11. Reading Lines with Continuation Characters
			Recipe 19.12. Iterating on a Stream of Data Blocks as a Stream of Lines
			Recipe 19.13. Fetching Large Record Sets from a Database with a Generator
			Recipe 19.14. Merging Sorted Sequences
			Recipe 19.15. Generating Permutations, Combinations, and Selections
			Recipe 19.16. Generating the Partitions of an Integer
			Recipe 19.17. Duplicating an Iterator
			Recipe 19.18. Looking Ahead into an Iterator
			Recipe 19.19. Simplifying Queue-Consumer Threads
			Recipe 19.20. Running an Iterator in Another Thread
			Recipe 19.21. Computing a Summary Report with itertools.groupby
		Chapter 20. Descriptors, Decorators,and Metaclasses
			Introduction
			Recipe 20.1. Getting Fresh Default Values at Each Function Call
			Recipe 20.2. Coding Properties as Nested Functions
			Recipe 20.3. Aliasing Attribute Values
			Recipe 20.4. Caching Attribute Values
			Recipe 20.5. Using One Method as Accessorfor Multiple Attributes
			Recipe 20.6. Adding Functionality to a Class by Wrapping a Method
			Recipe 20.7. Adding Functionality to a Class by Enriching All Methods
			Recipe 20.8. Adding a Method to a Class Instance at Runtime
			Recipe 20.9. Checking Whether Interfaces Are Implemented
			Recipe 20.10. Using _ _new_ _ and _ _init_ _ Appropriately in Custom Metaclasses
			Recipe 20.11. Allowing Chaining of Mutating List Methods
			Recipe 20.12. Using Cooperative Super calls with Terser Syntax
			Recipe 20.13. Initializing Instance Attributes Without Using _ _init_ _
			Recipe 20.14. Automatic Initialization of Instance Attributes
			Recipe 20.15. Upgrading Class Instances Automatically on reload
			Recipe 20.16. Binding Constants at Compile Time
			Recipe 20.17. Solving Metaclass Conflicts
		Colophon