第1页 / 共704页
第2页 / 共704页
第3页 / 共704页
第4页 / 共704页
第5页 / 共704页
第6页 / 共704页
第7页 / 共704页
第8页 / 共704页
Python Cookbook 3rd, third edition - 完美版.pdf
Copyright
Table of Contents
Preface
Who This Book Is For
Who This Book Is Not For
Conventions Used in This Book
Online Code Examples
Using Code Examples
Safari® Books Online
How to Contact Us
Acknowledgments
David Beazley’s Acknowledgments
Brian Jones’ Acknowledgments
Chapter 1. Data Structures and Algorithms
1.1. Unpacking a Sequence into Separate Variables
Problem
Solution
Discussion
1.2. Unpacking Elements from Iterables of Arbitrary Length
Problem
Solution
Discussion
1.3. Keeping the Last N Items
Problem
Solution
Discussion
1.4. Finding the Largest or Smallest N Items
Problem
Solution
Discussion
1.5. Implementing a Priority Queue
Problem
Solution
Discussion
1.6. Mapping Keys to Multiple Values in a Dictionary
Problem
Solution
Discussion
1.7. Keeping Dictionaries in Order
Problem
Solution
Discussion
1.8. Calculating with Dictionaries
Problem
Solution
Discussion
1.9. Finding Commonalities in Two Dictionaries
Problem
Solution
Discussion
1.10. Removing Duplicates from a Sequence while Maintaining Order
Problem
Solution
Discussion
1.11. Naming a Slice
Problem
Solution
Discussion
1.12. Determining the Most Frequently Occurring Items in a Sequence
Problem
Solution
Discussion
1.13. Sorting a List of Dictionaries by a Common Key
Problem
Solution
Discussion
1.14. Sorting Objects Without Native Comparison Support
Problem
Solution
Discussion
1.15. Grouping Records Together Based on a Field
Problem
Solution
Discussion
1.16. Filtering Sequence Elements
Problem
Solution
Discussion
1.17. Extracting a Subset of a Dictionary
Problem
Solution
Discussion
1.18. Mapping Names to Sequence Elements
Problem
Solution
Discussion
1.19. Transforming and Reducing Data at the Same Time
Problem
Solution
Discussion
1.20. Combining Multiple Mappings into a Single Mapping
Problem
Solution
Discussion
Chapter 2. Strings and Text
2.1. Splitting Strings on Any of Multiple Delimiters
Problem
Solution
Discussion
2.2. Matching Text at the Start or End of a String
Problem
Solution
Discussion
2.3. Matching Strings Using Shell Wildcard Patterns
Problem
Solution
Discussion
2.4. Matching and Searching for Text Patterns
Problem
Solution
Discussion
2.5. Searching and Replacing Text
Problem
Solution
Discussion
2.6. Searching and Replacing Case-Insensitive Text
Problem
Solution
Discussion
2.7. Specifying a Regular Expression for the Shortest Match
Problem
Solution
Discussion
2.8. Writing a Regular Expression for Multiline Patterns
Problem
Solution
Discussion
2.9. Normalizing Unicode Text to a Standard Representation
Problem
Solution
Discussion
2.10. Working with Unicode Characters in Regular Expressions
Problem
Solution
Discussion
2.11. Stripping Unwanted Characters from Strings
Problem
Solution
Discussion
2.12. Sanitizing and Cleaning Up Text
Problem
Solution
Discussion
2.13. Aligning Text Strings
Problem
Solution
Discussion
2.14. Combining and Concatenating Strings
Problem
Solution
Discussion
2.15. Interpolating Variables in Strings
Problem
Solution
Discussion
2.16. Reformatting Text to a Fixed Number of Columns
Problem
Solution
Discussion
2.17. Handling HTML and XML Entities in Text
Problem
Solution
Discussion
2.18. Tokenizing Text
Problem
Solution
Discussion
2.19. Writing a Simple Recursive Descent Parser
Problem
Solution
Discussion
2.20. Performing Text Operations on Byte Strings
Problem
Solution
Discussion
Chapter 3. Numbers, Dates, and Times
3.1. Rounding Numerical Values
Problem
Solution
Discussion
3.2. Performing Accurate Decimal Calculations
Problem
Solution
Discussion
3.3. Formatting Numbers for Output
Problem
Solution
Discussion
3.4. Working with Binary, Octal, and Hexadecimal Integers
Problem
Solution
Discussion
3.5. Packing and Unpacking Large Integers from Bytes
Problem
Solution
Discussion
3.6. Performing Complex-Valued Math
Problem
Solution
Discussion
3.7. Working with Infinity and NaNs
Problem
Solution
Discussion
3.8. Calculating with Fractions
Problem
Solution
Discussion
3.9. Calculating with Large Numerical Arrays
Problem
Solution
Discussion
3.10. Performing Matrix and Linear Algebra Calculations
Problem
Solution
Discussion
3.11. Picking Things at Random
Problem
Solution
Discussion
3.12. Converting Days to Seconds, and Other Basic Time Conversions
Problem
Solution
Discussion
3.13. Determining Last Friday’s Date
Problem
Solution
Discussion
3.14. Finding the Date Range for the Current Month
Problem
Solution
Discussion
3.15. Converting Strings into Datetimes
Problem
Solution
Discussion
3.16. Manipulating Dates Involving Time Zones
Problem
Solution
Discussion
Chapter 4. Iterators and Generators
4.1. Manually Consuming an Iterator
Problem
Solution
Discussion
4.2. Delegating Iteration
Problem
Solution
Discussion
4.3. Creating New Iteration Patterns with Generators
Problem
Solution
Discussion
4.4. Implementing the Iterator Protocol
Problem
Solution
Discussion
4.5. Iterating in Reverse
Problem
Solution
Discussion
4.6. Defining Generator Functions with Extra State
Problem
Solution
Discussion
4.7. Taking a Slice of an Iterator
Problem
Solution
Discussion
4.8. Skipping the First Part of an Iterable
Problem
Solution
Discussion
4.9. Iterating Over All Possible Combinations or Permutations
Problem
Solution
Discussion
4.10. Iterating Over the Index-Value Pairs of a Sequence
Problem
Solution
Discussion
4.11. Iterating Over Multiple Sequences Simultaneously
Problem
Solution
Discussion
4.12. Iterating on Items in Separate Containers
Problem
Solution
Discussion
4.13. Creating Data Processing Pipelines
Problem
Solution
Discussion
4.14. Flattening a Nested Sequence
Problem
Solution
Discussion
4.15. Iterating in Sorted Order Over Merged Sorted Iterables
Problem
Solution
Discussion
4.16. Replacing Infinite while Loops with an Iterator
Problem
Solution
Discussion
Chapter 5. Files and I/O
5.1. Reading and Writing Text Data
Problem
Solution
Discussion
5.2. Printing to a File
Problem
Solution
Discussion
5.3. Printing with a Different Separator or Line Ending
Problem
Solution
Discussion
5.4. Reading and Writing Binary Data
Problem
Solution
Discussion
5.5. Writing to a File That Doesn’t Already Exist
Problem
Solution
Discussion
5.6. Performing I/O Operations on a String
Problem
Solution
Discussion
5.7. Reading and Writing Compressed Datafiles
Problem
Solution
Discussion
5.8. Iterating Over Fixed-Sized Records
Problem
Solution
Discussion
5.9. Reading Binary Data into a Mutable Buffer
Problem
Solution
Discussion
5.10. Memory Mapping Binary Files
Problem
Solution
Discussion
5.11. Manipulating Pathnames
Problem
Solution
Discussion
5.12. Testing for the Existence of a File
Problem
Solution
Discussion
5.13. Getting a Directory Listing
Problem
Solution
Discussion
5.14. Bypassing Filename Encoding
Problem
Solution
Discussion
5.15. Printing Bad Filenames
Problem
Solution
Discussion
5.16. Adding or Changing the Encoding of an Already Open File
Problem
Solution
Discussion
5.17. Writing Bytes to a Text File
Problem
Solution
Discussion
5.18. Wrapping an Existing File Descriptor As a File Object
Problem
Solution
Discussion
5.19. Making Temporary Files and Directories
Problem
Solution
Discussion
5.20. Communicating with Serial Ports
Problem
Solution
Discussion
5.21. Serializing Python Objects
Problem
Solution
Discussion
Chapter 6. Data Encoding and Processing
6.1. Reading and Writing CSV Data
Problem
Solution
Discussion
6.2. Reading and Writing JSON Data
Problem
Solution
Discussion
6.3. Parsing Simple XML Data
Problem
Solution
Discussion
6.4. Parsing Huge XML Files Incrementally
Problem
Solution
Discussion
6.5. Turning a Dictionary into XML
Problem
Solution
Discussion
6.6. Parsing, Modifying, and Rewriting XML
Problem
Solution
Discussion
6.7. Parsing XML Documents with Namespaces
Problem
Solution
Discussion
6.8. Interacting with a Relational Database
Problem
Solution
Discussion
6.9. Decoding and Encoding Hexadecimal Digits
Problem
Solution
Discussion
6.10. Decoding and Encoding Base64
Problem
Solution
Discussion
6.11. Reading and Writing Binary Arrays of Structures
Problem
Solution
Discussion
6.12. Reading Nested and Variable-Sized Binary Structures
Problem
Solution
Discussion
6.13. Summarizing Data and Performing Statistics
Problem
Solution
Discussion
Chapter 7. Functions
7.1. Writing Functions That Accept Any Number of Arguments
Problem
Solution
Discussion
7.2. Writing Functions That Only Accept Keyword Arguments
Problem
Solution
Discussion
7.3. Attaching Informational Metadata to Function Arguments
Problem
Solution
Discussion
7.4. Returning Multiple Values from a Function
Problem
Solution
Discussion
7.5. Defining Functions with Default Arguments
Problem
Solution
Discussion
7.6. Defining Anonymous or Inline Functions
Problem
Solution
Discussion
7.7. Capturing Variables in Anonymous Functions
Problem
Solution
Discussion
7.8. Making an N-Argument Callable Work As a Callable with Fewer Arguments
Problem
Solution
Discussion
7.9. Replacing Single Method Classes with Functions
Problem
Solution
Discussion
7.10. Carrying Extra State with Callback Functions
Problem
Solution
Discussion
7.11. Inlining Callback Functions
Problem
Solution
Discussion
7.12. Accessing Variables Defined Inside a Closure
Problem
Solution
Discussion
Chapter 8. Classes and Objects
8.1. Changing the String Representation of Instances
Problem
Solution
Discussion
8.2. Customizing String Formatting
Problem
Solution
Discussion
8.3. Making Objects Support the Context-Management Protocol
Problem
Solution
Discussion
8.4. Saving Memory When Creating a Large Number of Instances
Problem
Solution
Discussion
8.5. Encapsulating Names in a Class
Problem
Solution
Discussion
8.6. Creating Managed Attributes
Problem
Solution
Discussion
8.7. Calling a Method on a Parent Class
Problem
Solution
Discussion
8.8. Extending a Property in a Subclass
Problem
Solution
Discussion
8.9. Creating a New Kind of Class or Instance Attribute
Problem
Solution
Discussion
8.10. Using Lazily Computed Properties
Problem
Solution
Discussion
8.11. Simplifying the Initialization of Data Structures
Problem
Solution
Discussion
8.12. Defining an Interface or Abstract Base Class
Problem
Solution
Discussion
8.13. Implementing a Data Model or Type System
Problem
Solution
Discussion
8.14. Implementing Custom Containers
Problem
Solution
Discussion
8.15. Delegating Attribute Access
Problem
Solution
Discussion
8.16. Defining More Than One Constructor in a Class
Problem
Solution
Discussion
8.17. Creating an Instance Without Invoking init
Problem
Solution
Discussion
8.18. Extending Classes with Mixins
Problem
Solution
Discussion
8.19. Implementing Stateful Objects or State Machines
Problem
Solution
Discussion
8.20. Calling a Method on an Object Given the Name As a String
Problem
Solution
Discussion
8.21. Implementing the Visitor Pattern
Problem
Solution
Discussion
8.22. Implementing the Visitor Pattern Without Recursion
Problem
Solution
Discussion
8.23. Managing Memory in Cyclic Data Structures
Problem
Solution
Discussion
8.24. Making Classes Support Comparison Operations
Problem
Solution
Discussion
8.25. Creating Cached Instances
Problem
Solution
Discussion
Chapter 9. Metaprogramming
9.1. Putting a Wrapper Around a Function
Problem
Solution
Discussion
9.2. Preserving Function Metadata When Writing Decorators
Problem
Solution
Discussion
9.3. Unwrapping a Decorator
Problem
Solution
Discussion
9.4. Defining a Decorator That Takes Arguments
Problem
Solution
Discussion
9.5. Defining a Decorator with User Adjustable Attributes
Problem
Solution
Discussion
9.6. Defining a Decorator That Takes an Optional Argument
Problem
Solution
Discussion
9.7. Enforcing Type Checking on a Function Using a Decorator
Problem
Solution
Discussion
9.8. Defining Decorators As Part of a Class
Problem
Solution
Discussion
9.9. Defining Decorators As Classes
Problem
Solution
Discussion
9.10. Applying Decorators to Class and Static Methods
Problem
Solution
Discussion
9.11. Writing Decorators That Add Arguments to Wrapped Functions
Problem
Solution
Discussion
9.12. Using Decorators to Patch Class Definitions
Problem
Solution
Discussion
9.13. Using a Metaclass to Control Instance Creation
Problem
Solution
Discussion
9.14. Capturing Class Attribute Definition Order
Problem
Solution
Discussion
9.15. Defining a Metaclass That Takes Optional Arguments
Problem
Solution
Discussion
9.16. Enforcing an Argument Signature on *args and **kwargs
Problem
Solution
Discussion
9.17. Enforcing Coding Conventions in Classes
Problem
Solution
Discussion
9.18. Defining Classes Programmatically
Problem
Solution
Discussion
9.19. Initializing Class Members at Definition Time
Problem
Solution
Discussion
9.20. Implementing Multiple Dispatch with Function Annotations
Problem
Solution
Discussion
9.21. Avoiding Repetitive Property Methods
Problem
Solution
Discussion
9.22. Defining Context Managers the Easy Way
Problem
Solution
Discussion
9.23. Executing Code with Local Side Effects
Problem
Solution
Discussion
9.24. Parsing and Analyzing Python Source
Problem
Solution
Discussion
9.25. Disassembling Python Byte Code
Problem
Solution
Discussion
Chapter 10. Modules and Packages
10.1. Making a Hierarchical Package of Modules
Problem
Solution
Discussion
10.2. Controlling the Import of Everything
Problem
Solution
Discussion
10.3. Importing Package Submodules Using Relative Names
Problem
Solution
Discussion
10.4. Splitting a Module into Multiple Files
Problem
Solution
Discussion
10.5. Making Separate Directories of Code Import Under a Common Namespace
Problem
Solution
Discussion
10.6. Reloading Modules
Problem
Solution
Discussion
10.7. Making a Directory or Zip File Runnable As a Main Script
Problem
Solution
Discussion
10.8. Reading Datafiles Within a Package
Problem
Solution
Discussion
10.9. Adding Directories to sys.path
Problem
Solution
Discussion
10.10. Importing Modules Using a Name Given in a String
Problem
Solution
Discussion
10.11. Loading Modules from a Remote Machine Using Import Hooks
Problem
Solution
Discussion
10.12. Patching Modules on Import
Problem
Solution
Discussion
10.13. Installing Packages Just for Yourself
Problem
Solution
Discussion
10.14. Creating a New Python Environment
Problem
Solution
Discussion
10.15. Distributing Packages
Problem
Solution
Discussion
Chapter 11. Network and Web Programming
11.1. Interacting with HTTP Services As a Client
Problem
Solution
Discussion
11.2. Creating a TCP Server
Problem
Solution
Discussion
11.3. Creating a UDP Server
Problem
Solution
Discussion
11.4. Generating a Range of IP Addresses from a CIDR Address
Problem
Solution
Discussion
11.5. Creating a Simple REST-Based Interface
Problem
Solution
Discussion
11.6. Implementing a Simple Remote Procedure Call with XML-RPC
Problem
Solution
Discussion
11.7. Communicating Simply Between Interpreters
Problem
Solution
Discussion
11.8. Implementing Remote Procedure Calls
Problem
Solution
Discussion
11.9. Authenticating Clients Simply
Problem
Solution
Discussion
11.10. Adding SSL to Network Services
Problem
Solution
Discussion
11.11. Passing a Socket File Descriptor Between Processes
Problem
Solution
Discussion
11.12. Understanding Event-Driven I/O
Problem
Solution
Discussion
11.13. Sending and Receiving Large Arrays
Problem
Solution
Discussion
Chapter 12. Concurrency
12.1. Starting and Stopping Threads
Problem
Solution
Discussion
12.2. Determining If a Thread Has Started
Problem
Solution
Discussion
12.3. Communicating Between Threads
Problem
Solution
Discussion
12.4. Locking Critical Sections
Problem
Solution
Discussion
12.5. Locking with Deadlock Avoidance
Problem
Solution
Discussion
12.6. Storing Thread-Specific State
Problem
Solution
Discussion
12.7. Creating a Thread Pool
Problem
Solution
Discussion
12.8. Performing Simple Parallel Programming
Problem
Solution
Discussion
12.9. Dealing with the GIL (and How to Stop Worrying About It)
Problem
Solution
Discussion
12.10. Defining an Actor Task
Problem
Solution
Discussion
12.11. Implementing Publish/Subscribe Messaging
Problem
Solution
Discussion
12.12. Using Generators As an Alternative to Threads
Problem
Solution
Discussion
12.13. Polling Multiple Thread Queues
Problem
Solution
Discussion
12.14. Launching a Daemon Process on Unix
Problem
Solution
Discussion
Chapter 13. Utility Scripting and System Administration
13.1. Accepting Script Input via Redirection, Pipes, or Input Files
Problem
Solution
Discussion
13.2. Terminating a Program with an Error Message
Problem
Solution
Discussion
13.3. Parsing Command-Line Options
Problem
Solution
Discussion
13.4. Prompting for a Password at Runtime
Problem
Solution
Discussion
13.5. Getting the Terminal Size
Problem
Solution
Discussion
13.6. Executing an External Command and Getting Its Output
Problem
Solution
Discussion
13.7. Copying or Moving Files and Directories
Problem
Solution
Discussion
13.8. Creating and Unpacking Archives
Problem
Solution
Discussion
13.9. Finding Files by Name
Problem
Solution
Discussion
13.10. Reading Configuration Files
Problem
Solution
Discussion
13.11. Adding Logging to Simple Scripts
Problem
Solution
Discussion
13.12. Adding Logging to Libraries
Problem
Solution
Discussion
13.13. Making a Stopwatch Timer
Problem
Solution
Discussion
13.14. Putting Limits on Memory and CPU Usage
Problem
Solution
Discussion
13.15. Launching a Web Browser
Problem
Solution
Discussion
Chapter 14. Testing, Debugging, and Exceptions
14.1. Testing Output Sent to stdout
Problem
Solution
Discussion
14.2. Patching Objects in Unit Tests
Problem
Solution
Discussion
14.3. Testing for Exceptional Conditions in Unit Tests
Problem
Solution
Discussion
14.4. Logging Test Output to a File
Problem
Solution
Discussion
14.5. Skipping or Anticipating Test Failures
Problem
Solution
Discussion
14.6. Handling Multiple Exceptions
Problem
Solution
Discussion
14.7. Catching All Exceptions
Problem
Solution
Discussion
14.8. Creating Custom Exceptions
Problem
Solution
Discussion
14.9. Raising an Exception in Response to Another Exception
Problem
Solution
Discussion
14.10. Reraising the Last Exception
Problem
Solution
Discussion
14.11. Issuing Warning Messages
Problem
Solution
Discussion
14.12. Debugging Basic Program Crashes
Problem
Solution
Discussion
14.13. Profiling and Timing Your Program
Problem
Solution
Discussion
14.14. Making Your Programs Run Faster
Problem
Solution
Discussion
Chapter 15. C Extensions
15.1. Accessing C Code Using ctypes
Problem
Solution
Discussion
15.2. Writing a Simple C Extension Module
Problem
Solution
Discussion
15.3. Writing an Extension Function That Operates on Arrays
Problem
Solution
Discussion
15.4. Managing Opaque Pointers in C Extension Modules
Problem
Solution
Discussion
15.5. Defining and Exporting C APIs from Extension Modules
Problem
Solution
Discussion
15.6. Calling Python from C
Problem
Solution
Discussion
15.7. Releasing the GIL in C Extensions
Problem
Solution
Discussion
15.8. Mixing Threads from C and Python
Problem
Solution
Discussion
15.9. Wrapping C Code with Swig
Problem
Solution
Discussion
15.10. Wrapping Existing C Code with Cython
Problem
Solution
Discussion
15.11. Using Cython to Write High-Performance Array Operations
Problem
Solution
Discussion
15.12. Turning a Function Pointer into a Callable
Problem
Solution
Discussion
15.13. Passing NULL-Terminated Strings to C Libraries
Problem
Solution
Discussion
15.14. Passing Unicode Strings to C Libraries
Problem
Solution
Discussion
15.15. Converting C Strings to Python
Problem
Solution
Discussion
15.16. Working with C Strings of Dubious Encoding
Problem
Solution
Discussion
15.17. Passing Filenames to C Extensions
Problem
Solution
Discussion
15.18. Passing Open Files to C Extensions
Problem
Solution
Discussion
15.19. Reading File-Like Objects from C
Problem
Solution
Discussion
15.20. Consuming an Iterable from C
Problem
Solution
Discussion
15.21. Diagnosing Segmentation Faults
Problem
Solution
Discussion
Appendix A. Further Reading
Online Resources
Books for Learning Python
Advanced Books
Index
About the Authors
THIRD EDITION
Python Cookbook
David Beazley and Brian K. Jones
www.it-ebooks.info
Python Cookbook, Third Edition
by David Beazley and Brian K. Jones
Copyright © 2013 David Beazley and Brian Jones. All rights reserved.
Printed in the United States of America.
Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472.
O’Reilly books may be purchased for educational, business, or sales promotional use. Online editions are
also available for most titles (http://my.safaribooksonline.com). For more information, contact our corporate/
institutional sales department: 800-998-9938 or corporate@oreilly.com.
Editors: Meghan Blanchette and Rachel Roumeliotis
Production Editor: Kristen Borg
Copyeditor: Jasmine Kwityn
Proofreader: BIM Proofreading Services
Indexer: WordCo Indexing Services
Cover Designer: Karen Montgomery
Interior Designer: David Futato
Illustrator: Robert Romano
May 2013:
Third Edition
Revision History for the Third Edition:
2013-05-08: First release
See http://oreilly.com/catalog/errata.csp?isbn=9781449340377 for release details.
Nutshell Handbook, the Nutshell Handbook logo, and the O’Reilly logo are registered trademarks of O’Reilly
Media, Inc. Python Cookbook, the image of a springhaas, and related trade dress are trademarks of O’Reilly
Media, Inc.
Many of the designations used by manufacturers and sellers to distinguish their products are claimed as
trademarks. Where those designations appear in this book, and O’Reilly Media, Inc., was aware of a trade‐
mark claim, the designations have been printed in caps or initial caps.
While every precaution has been taken in the preparation of this book, the publisher and authors assume
no responsibility for errors or omissions, or for damages resulting from the use of the information contained
herein.
ISBN: 978-1-449-34037-7
[LSI]
www.it-ebooks.info
Table of Contents
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
1. Data Structures and Algorithms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
1.1. Unpacking a Sequence into Separate Variables 1
1.2. Unpacking Elements from Iterables of Arbitrary Length 3
1.3. Keeping the Last N Items 5
1.4. Finding the Largest or Smallest N Items 7
1.5. Implementing a Priority Queue 8
1.6. Mapping Keys to Multiple Values in a Dictionary 11
1.7. Keeping Dictionaries in Order 12
1.8. Calculating with Dictionaries 13
1.9. Finding Commonalities in Two Dictionaries 15
1.10. Removing Duplicates from a Sequence while Maintaining Order 17
1.11. Naming a Slice 18
1.12. Determining the Most Frequently Occurring Items in a Sequence 20
1.13. Sorting a List of Dictionaries by a Common Key 21
1.14. Sorting Objects Without Native Comparison Support 23
1.15. Grouping Records Together Based on a Field 24
1.16. Filtering Sequence Elements 26
1.17. Extracting a Subset of a Dictionary 28
1.18. Mapping Names to Sequence Elements 29
1.19. Transforming and Reducing Data at the Same Time 32
1.20. Combining Multiple Mappings into a Single Mapping 33
2. Strings and Text. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2.1. Splitting Strings on Any of Multiple Delimiters 37
2.2. Matching Text at the Start or End of a String 38
2.3. Matching Strings Using Shell Wildcard Patterns 40
2.4. Matching and Searching for Text Patterns 42
www.it-ebooks.info
iii
2.5. Searching and Replacing Text 45
2.6. Searching and Replacing Case-Insensitive Text 46
2.7. Specifying a Regular Expression for the Shortest Match 47
2.8. Writing a Regular Expression for Multiline Patterns 48
2.9. Normalizing Unicode Text to a Standard Representation 50
2.10. Working with Unicode Characters in Regular Expressions 52
2.11. Stripping Unwanted Characters from Strings 53
2.12. Sanitizing and Cleaning Up Text 54
2.13. Aligning Text Strings 57
2.14. Combining and Concatenating Strings 58
2.15. Interpolating Variables in Strings 61
2.16. Reformatting Text to a Fixed Number of Columns 64
2.17. Handling HTML and XML Entities in Text 65
2.18. Tokenizing Text 66
2.19. Writing a Simple Recursive Descent Parser 69
2.20. Performing Text Operations on Byte Strings 78
3. Numbers, Dates, and Times. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
3.1. Rounding Numerical Values 83
3.2. Performing Accurate Decimal Calculations 84
3.3. Formatting Numbers for Output 87
3.4. Working with Binary, Octal, and Hexadecimal Integers 89
3.5. Packing and Unpacking Large Integers from Bytes 90
3.6. Performing Complex-Valued Math 92
3.7. Working with Infinity and NaNs 94
3.8. Calculating with Fractions 96
3.9. Calculating with Large Numerical Arrays 97
3.10. Performing Matrix and Linear Algebra Calculations 100
3.11. Picking Things at Random 102
3.12. Converting Days to Seconds, and Other Basic Time Conversions 104
3.13. Determining Last Friday’s Date 106
3.14. Finding the Date Range for the Current Month 107
3.15. Converting Strings into Datetimes 109
3.16. Manipulating Dates Involving Time Zones 110
4.
Iterators and Generators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
113
4.1. Manually Consuming an Iterator 113
4.2. Delegating Iteration 114
4.3. Creating New Iteration Patterns with Generators 115
4.4. Implementing the Iterator Protocol 117
4.5. Iterating in Reverse 119
4.6. Defining Generator Functions with Extra State 120
iv
|
Table of Contents
www.it-ebooks.info
4.7. Taking a Slice of an Iterator 122
4.8. Skipping the First Part of an Iterable 123
4.9. Iterating Over All Possible Combinations or Permutations 125
4.10. Iterating Over the Index-Value Pairs of a Sequence 127
4.11. Iterating Over Multiple Sequences Simultaneously 129
4.12. Iterating on Items in Separate Containers 131
4.13. Creating Data Processing Pipelines 132
4.14. Flattening a Nested Sequence 135
4.15. Iterating in Sorted Order Over Merged Sorted Iterables 136
4.16. Replacing Infinite while Loops with an Iterator 138
5. Files and I/O. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
5.1. Reading and Writing Text Data 141
5.2. Printing to a File 144
5.3. Printing with a Different Separator or Line Ending 144
5.4. Reading and Writing Binary Data 145
5.5. Writing to a File That Doesn’t Already Exist 147
5.6. Performing I/O Operations on a String 148
5.7. Reading and Writing Compressed Datafiles 149
5.8. Iterating Over Fixed-Sized Records 151
5.9. Reading Binary Data into a Mutable Buffer 152
5.10. Memory Mapping Binary Files 153
5.11. Manipulating Pathnames 156
5.12. Testing for the Existence of a File 157
5.13. Getting a Directory Listing 158
5.14. Bypassing Filename Encoding 160
5.15. Printing Bad Filenames 161
5.16. Adding or Changing the Encoding of an Already Open File 163
5.17. Writing Bytes to a Text File 165
5.18. Wrapping an Existing File Descriptor As a File Object 166
5.19. Making Temporary Files and Directories 167
5.20. Communicating with Serial Ports 170
5.21. Serializing Python Objects 171
6. Data Encoding and Processing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
6.1. Reading and Writing CSV Data 175
6.2. Reading and Writing JSON Data 179
6.3. Parsing Simple XML Data 183
6.4. Parsing Huge XML Files Incrementally 186
6.5. Turning a Dictionary into XML 189
6.6. Parsing, Modifying, and Rewriting XML 191
6.7. Parsing XML Documents with Namespaces 193
Table of Contents
|
v
www.it-ebooks.info
6.8. Interacting with a Relational Database 195
6.9. Decoding and Encoding Hexadecimal Digits 197
6.10. Decoding and Encoding Base64 199
6.11. Reading and Writing Binary Arrays of Structures 199
6.12. Reading Nested and Variable-Sized Binary Structures 203
6.13. Summarizing Data and Performing Statistics 214
7. Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
7.1. Writing Functions That Accept Any Number of Arguments 217
7.2. Writing Functions That Only Accept Keyword Arguments 219
7.3. Attaching Informational Metadata to Function Arguments 220
7.4. Returning Multiple Values from a Function 221
7.5. Defining Functions with Default Arguments 222
7.6. Defining Anonymous or Inline Functions 224
7.7. Capturing Variables in Anonymous Functions 225
7.8. Making an N-Argument Callable Work As a Callable with Fewer
Arguments 227
7.9. Replacing Single Method Classes with Functions 231
7.10. Carrying Extra State with Callback Functions 232
7.11. Inlining Callback Functions 235
7.12. Accessing Variables Defined Inside a Closure 238
8. Classes and Objects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
8.1. Changing the String Representation of Instances 243
8.2. Customizing String Formatting 245
8.3. Making Objects Support the Context-Management Protocol 246
8.4. Saving Memory When Creating a Large Number of Instances 248
8.5. Encapsulating Names in a Class 250
8.6. Creating Managed Attributes 251
8.7. Calling a Method on a Parent Class 256
8.8. Extending a Property in a Subclass 260
8.9. Creating a New Kind of Class or Instance Attribute 264
8.10. Using Lazily Computed Properties 267
8.11. Simplifying the Initialization of Data Structures 270
8.12. Defining an Interface or Abstract Base Class 274
8.13. Implementing a Data Model or Type System 277
8.14. Implementing Custom Containers 283
8.15. Delegating Attribute Access 287
8.16. Defining More Than One Constructor in a Class 291
8.17. Creating an Instance Without Invoking init 293
8.18. Extending Classes with Mixins 294
8.19. Implementing Stateful Objects or State Machines 299
vi
|
Table of Contents
www.it-ebooks.info
8.20. Calling a Method on an Object Given the Name As a String 305
8.21. Implementing the Visitor Pattern 306
8.22. Implementing the Visitor Pattern Without Recursion 311
8.23. Managing Memory in Cyclic Data Structures 317
8.24. Making Classes Support Comparison Operations 321
8.25. Creating Cached Instances 323
9. Metaprogramming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
9.1. Putting a Wrapper Around a Function 329
9.2. Preserving Function Metadata When Writing Decorators 331
9.3. Unwrapping a Decorator 333
9.4. Defining a Decorator That Takes Arguments 334
9.5. Defining a Decorator with User Adjustable Attributes 336
9.6. Defining a Decorator That Takes an Optional Argument 339
9.7. Enforcing Type Checking on a Function Using a Decorator 341
9.8. Defining Decorators As Part of a Class 345
9.9. Defining Decorators As Classes 347
9.10. Applying Decorators to Class and Static Methods 350
9.11. Writing Decorators That Add Arguments to Wrapped Functions 352
9.12. Using Decorators to Patch Class Definitions 355
9.13. Using a Metaclass to Control Instance Creation 356
9.14. Capturing Class Attribute Definition Order 359
9.15. Defining a Metaclass That Takes Optional Arguments 362
9.16. Enforcing an Argument Signature on *args and **kwargs 364
9.17. Enforcing Coding Conventions in Classes 367
9.18. Defining Classes Programmatically 370
9.19. Initializing Class Members at Definition Time 374
9.20. Implementing Multiple Dispatch with Function Annotations 376
9.21. Avoiding Repetitive Property Methods 382
9.22. Defining Context Managers the Easy Way 384
9.23. Executing Code with Local Side Effects 386
9.24. Parsing and Analyzing Python Source 388
9.25. Disassembling Python Byte Code 392
10. Modules and Packages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
10.1. Making a Hierarchical Package of Modules 397
10.2. Controlling the Import of Everything 398
10.3. Importing Package Submodules Using Relative Names 399
10.4. Splitting a Module into Multiple Files 401
10.5. Making Separate Directories of Code Import Under a Common
Namespace 404
10.6. Reloading Modules 406
Table of Contents
|
vii
www.it-ebooks.info
10.7. Making a Directory or Zip File Runnable As a Main Script 407
10.8. Reading Datafiles Within a Package 408
10.9. Adding Directories to sys.path 409
10.10. Importing Modules Using a Name Given in a String 411
10.11. Loading Modules from a Remote Machine Using Import Hooks 412
10.12. Patching Modules on Import 428
10.13. Installing Packages Just for Yourself 431
10.14. Creating a New Python Environment 432
10.15. Distributing Packages 433
11. Network and Web Programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437
11.1. Interacting with HTTP Services As a Client 437
11.2. Creating a TCP Server 441
11.3. Creating a UDP Server 445
11.4. Generating a Range of IP Addresses from a CIDR Address 447
11.5. Creating a Simple REST-Based Interface 449
11.6. Implementing a Simple Remote Procedure Call with XML-RPC 454
11.7. Communicating Simply Between Interpreters 456
11.8. Implementing Remote Procedure Calls 458
11.9. Authenticating Clients Simply 461
11.10. Adding SSL to Network Services 464
11.11. Passing a Socket File Descriptor Between Processes 470
11.12. Understanding Event-Driven I/O 475
11.13. Sending and Receiving Large Arrays 481
12. Concurrency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485
12.1. Starting and Stopping Threads 485
12.2. Determining If a Thread Has Started 488
12.3. Communicating Between Threads 491
12.4. Locking Critical Sections 497
12.5. Locking with Deadlock Avoidance 500
12.6. Storing Thread-Specific State 504
12.7. Creating a Thread Pool 505
12.8. Performing Simple Parallel Programming 509
12.9. Dealing with the GIL (and How to Stop Worrying About It) 513
12.10. Defining an Actor Task 516
12.11. Implementing Publish/Subscribe Messaging 520
12.12. Using Generators As an Alternative to Threads 524
12.13. Polling Multiple Thread Queues 531
12.14. Launching a Daemon Process on Unix 534
13. Utility Scripting and System Administration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 539
viii
|
Table of Contents
www.it-ebooks.info
相关推荐
2023年江西萍乡中考道德与法治真题及答案.doc
2012年重庆南川中考生物真题及答案.doc
2013年江西师范大学地理学综合及文艺理论基础考研真题.doc
2020年四川甘孜小升初语文真题及答案I卷.doc
2020年注册岩土工程师专业基础考试真题及答案.doc
2023-2024学年福建省厦门市九年级上学期数学月考试题及答案.doc
2021-2022学年辽宁省沈阳市大东区九年级上学期语文期末试题及答案.doc
2022-2023学年北京东城区初三第一学期物理期末试卷及答案.doc
2018上半年江西教师资格初中地理学科知识与教学能力真题及答案.doc
2012年河北国家公务员申论考试真题及答案-省级.doc
2020-2021学年江苏省扬州市江都区邵樊片九年级上学期数学第一次质量检测试题及答案.doc
2022下半年黑龙江教师资格证中学综合素质真题及答案.doc
