- Python Cookbook
- Foreword
- Preface
- 1. Python Shortcuts
- Introduction
- Swapping Values WithoutUsing a Temporary Variable
- Constructing a Dictionary Without Excessive Quoting
- Getting a Value from a Dictionary
- Adding an Entry to a Dictionary
- Associating Multiple Values with Each Key in a Dictionary
- Dispatching Using a Dictionary
- Collecting a Bunch of Named Items
- Finding the Intersection of Two Dictionaries
- Assigning and Testing with One Statement
- Using List Comprehensions Instead of map and filter
- Unzipping Simple List-Like Objects
- Flattening a Nested Sequence
- Looping in Parallel over Index and Sequence Items
- Looping Through Multiple Lists
- Spanning a Range Defined by Floats
- Transposing Two-Dimensional Arrays
- Creating Lists of Lists Without Sharing References
- 2. Searching and Sorting
- Introduction
- Sorting a Dictionary
- Processing Selected Pairs of Structured Data Efficiently
- Sorting While Guaranteeing Sort Stability
- Sorting by One Field, Then by Another
- Looking for Items in a Sorted Sequence Using Binary Search
- Sorting a List of Objects by an Attribute of the Objects
- Sorting by Item or by Attribute
- Selecting Random Elements from a List Without Repetition
- Performing Frequent Membership Tests on a Sequence
- Finding the Deep Index of an Item in an Embedded Sequence
- Showing Off Quicksort in Three Lines
- Sorting Objects Using SQL’s ORDER BY Syntax
- 3. Text
- Introduction
- Processing a String One Character at a Time
- Testing if an Object Is String-Like
- Aligning Strings
- Trimming Space from the Ends of a String
- Combining Strings
- Checking Whether a String Contains a Set of Characters
- Filtering a String for a Set of Characters
- Controlling Case
- Reversing a String by Words or Characters
- Accessing Substrings
- Changing the Indentation of a Multiline String
- Testing Whether a String Represents an Integer
- Expanding and Compressing Tabs
- Replacing Multiple Patterns in a Single Pass
- Converting Between Different Naming Conventions
- Converting Between Characters and Values
- Converting Between Unicode and Plain Strings
- Printing Unicode Characters to Standard Output
- Dispatching Based on Pattern Matches
- Evaluating Code Inside Strings
- Replacing Python Code with the Results of Executing That Code
- Module: Yet Another Python Templating Utility (YAPTU)
- Module: Roman Numerals
- 4. Files
- Introduction
- Reading from a File
- Writing to a File
- Searching and Replacing Text in a File
- Reading a Particular Line from a File
- Retrieving a Line at Random from a File of Unknown Size
- Counting Lines in a File
- Processing Every Word in a File
- Reading a Text File by Paragraphs
- Reading Lines with Continuation Characters
- Reading Data from ZIP Files
- Reading INI Configuration Files
- Sending Binary Data to Standard Output Under Windows
- Using Random-Access Input/Output
- Updating a Random-Access File
- Splitting a Path into All of Its Parts
- Treating Pathnames as Objects
- Creating Directories Including Necessary Parent Directories
- Walking Directory Trees
- Swapping One File Extension for Another Throughout a Directory Tree
- Finding a File Given an Arbitrary Search Path
- Finding a File on the Python Search Path
- Dynamically Changing the Python Search Path
- Computing Directory Sizes in a Cross-Platform Way
- File Locking Using a Cross-Platform API
- Versioning Filenames
- Module: Versioned Backups
- 5. Object-Oriented Programming
- Introduction
- Overriding a Built-In Method
- Getting All Members of a Class Hierarchy
- Calling a Superclass _ _init_ _ Method if It Exists
- Calling a Superclass Implementation of a Method
- Implementing Properties
- Implementing Static Methods
- Implementing Class Methods
- Delegating Automatically as an Alternative to Inheritance
- Decorating an Object with Print-Like Methods
- Checking if an Object Has Necessary Attributes
- Making a Fast Copy of an Object
- Adding Methods to a Class at Runtime
- Modifying the Class Hierarchy of an Instance
- Keeping References to Bound Methods Without Inhibiting Garbage Collection
- Defining Constants
- Managing Options
- Implementing a Set Class
- Implementing a Ring Buffer
- Implementing a Collection
- Delegating Messages to Multiple Objects
- Implementing the Singleton Design Pattern
- Avoiding the Singleton Design Pattern with the Borg Idiom
- Implementing the Null Object Design Pattern
- 6. Threads, Processes, and Synchronization
- Introduction
- Storing Per-Thread Information
- Terminating a Thread
- Allowing Multithreaded Read Access While Maintaining a Write Lock
- Running Functions in the Future
- Synchronizing All Methods in an Object
- Capturing the Output and Error Streams from a Unix Shell Command
- Forking a Daemon Process on Unix
- Determining if Another Instance of a Script Is Already Running in Windows
- Processing Windows Messages Using MsgWaitForMultipleObjects
- 7. System Administration
- Introduction
- Running a Command Repeatedly
- Generating Random Passwords
- Generating Non-Totally Random Passwords
- Checking the Status of a Unix Network Interface
- Calculating Apache Hits per IP Address
- Calculating the Rate of Client Cache Hits on Apache
- Manipulating the Environment on Windows NT/2000/XP
- Checking and Modifying the Set of Tasks Windows Automatically Runs at Logon
- Examining the Microsoft Windows Registry for a List of Name Server Addresses
- Getting Information About the Current User on Windows NT/2000
- Getting the Windows Service Name from Its Long Name
- Manipulating Windows Services
- Impersonating Principals on Windows
- Changing a Windows NT Password Using ADSI
- Working with Windows Scripting Host (WSH) from Python
- Displaying Decoded Hotkeys for Shortcuts in Windows
- 8. Databases and Persistence
- Introduction
- Serializing Data Using the marshal Module
- Serializing Data Using the pickle and cPickle Modules
- Using the cPickle Module on Classes and Instances
- Mutating Objects with shelve
- Accessing a MySQL Database
- Storing a BLOB in a MySQL Database
- Storing a BLOB in a PostgreSQL Database
- Generating a Dictionary Mapping from Field Names to Column Numbers
- Using dtuple for Flexible Access to Query Results
- Pretty-Printing the Contents of Database Cursors
- Establishing Database Connections Lazily
- Accessing a JDBC Database from a Jython Servlet
- Module: jet2sql—Creating a SQL DDL from an Access Database
- 9. User Interfaces
- Introduction
- Avoiding lambda in Writing Callback Functions
- Creating Menus with Tkinter
- Creating Dialog Boxes with Tkinter
- Supporting Multiple Values per Row in a Tkinter Listbox
- Embedding Inline GIFs Using Tkinter
- Combining Tkinter and Asynchronous I/O with Threads
- Using a wxPython Notebook with Panels
- Giving the User Unobtrusive Feedback During Data Entry with Qt
- Building GUI Solutions Independent of the Specific GUI Toolkit
- Creating Color Scales
- Using Publish/Subscribe Broadcasting to Loosen the Coupling Between GUI and Business Logic Systems
- Module: Building GTK GUIs Interactively
- 10. Network Programming
- Introduction
- Writing a TCP Client
- Writing a TCP Server
- Passing Messages with Socket Datagrams
- Finding Your Own Name and Address
- Converting IP Addresses
- Grabbing a Document from the Web
- Being an FTP Client
- Sending HTML Mail
- Sending Multipart MIME Email
- Bundling Files in a MIME Message
- Unpacking a Multipart MIME Message
- Module: PyHeartBeat—Detecting Inactive Computers
- Module: Interactive POP3 Mailbox Inspector
- Module: Watching for New IMAP Mail Using a GUI
- 11. Web Programming
- Introduction
- Testing Whether CGI Is Working
- Writing a CGI Script
- Using a Simple Dictionary for CGI Parameters
- Handling URLs Within a CGI Script
- Resuming the HTTP Download of a File
- Stripping Dangerous Tags and Javascript from HTML
- Running a Servlet with Jython
- Accessing Netscape Cookie Information
- Finding an Internet Explorer Cookie
- Module: Fetching Latitude/Longitude Data from the Web
- 12. Processing XML
- Introduction
- Checking XML Well-Formedness
- Counting Tags in a Document
- Extracting Text from an XML Document
- Transforming an XML Document Using XSLT
- Transforming an XML Document Using Python
- Parsing an XML File with xml.parsers.expat
- Converting Ad-Hoc Text into XML Markup
- Normalizing an XML Document
- Controlling XSLT Stylesheet Loading
- Autodetecting XML Encoding
- Module: XML Lexing (Shallow Parsing)
- Module: Converting a List of Equal-Length Lists into XML
- 13. Distributed Programming
- Introduction
- Making an XML-RPC Method Call
- Serving XML-RPC Requests
- Using XML-RPC with Medusa
- Writing a Web Service That Supports Both XML-RPC and SOAP
- Implementing a CORBA Client and Server
- Performing Remote Logins Using telnetlib
- Using Publish/Subscribe in a Distributed Middleware Architecture
- Using Request/Reply in a Distributed Middleware Architecture
- 14. Debugging and Testing
- Introduction
- Reloading All Loaded Modules
- Tracing Expressions and Comments in Debug Mode
- Wrapping Tracebacks in HTML
- Getting More Information from Tracebacks
- Starting the Debugger Automatically After an Uncaught Exception
- Logging and Tracing Across Platforms
- Determining the Name of the Current Function
- Introspecting the Call Stack with Older Versions of Python
- Debugging the Garbage-Collection Process
- Tracking Instances of Particular Classes
- 15. Programs About Programs
- Introduction
- Colorizing Python Source Using the Built-in Tokenizer
- Importing a Dynamically Generated Module
- Importing from a Module Whose Name Is Determined at Runtime
- Importing Modules with Automatic End-of-Line Conversions
- Simulating Enumerations in Python
- Modifying Methods in Place
- Associating Parameters with a Function (Currying)
- Composing Functions
- Adding Functionality to a Class
- Adding a Method to a Class Instance at Runtime
- Defining a Custom Metaclass to Control Class Behavior
- Module: Allowing the Python Profiler to Profile C Modules
- 16. Extending and Embedding
- Introduction
- Implementing a Simple Extension Type
- Translating a Python Sequence into a C Array with the PySequence_Fast Protocol
- Accessing a Python Sequence Item-by-Item with the Iterator Protocol
- Returning None from a Python-Callable C Function
- Coding the Methods of a Python Class in C
- Implementing C Function Callbacks to a Python Function
- Debugging Dynamically Loaded C Extensions with gdb
- Debugging Memory Problems
- Using SWIG-Generated Modules in a Multithreaded Environment
- 17. Algorithms
- Introduction
- Testing if a Variable Is Defined
- Evaluating Predicate Tests Across Sequences
- Removing Duplicates from a Sequence
- Removing Duplicates from a Sequence While Maintaining Sequence Order
- Simulating the Ternary Operator in Python
- Counting Items and Sorting by Incidence (Histograms)
- Memoizing (Caching) the Return Values of Functions
- Looking Up Words by Sound Similarity
- Computing Factorials with lambda
- Generating the Fibonacci Sequence
- Wrapping an Unbounded Iterator to Restrict Its Output
- Operating on Iterators
- Rolling Dice
- Implementing a First-In First-Out Container
- Modeling a Priority Queue
- Converting Numbers to Rationals via Farey Fractions
- Evaluating a Polynomial
- Module: Finding the Convex Hull of a Set of 2D Points
- Module: Parsing a String into a Date/Time Object Portably
- 18. List of Contributors
- Index
- Colophon
The following typographical conventions are used throughout this book:
- Italic
Used for commands, URLs, filenames, file extensions, directory or folder names, emphasis, and new terms where they are defined.
Constant widthUsed for all code listings and to designate anything that would appear literally in a Python or C program. This includes module names, method names, class names, function names, statements, and HTML tags.
Constant width italicUsed for general placeholders that indicate that an item should be replaced by some actual value in your own program.
Constant width boldUsed to emphasize particular lines within code listings and show output that is produced.
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