The Python 3 Standard Library by Example

Cover
Title Page
Copyright Page
Contents
Introduction
Acknowledgments
About the Author
Chapter 1 Text
1.1 string: Text Constants and Templates
1.1.1 Functions
1.1.2 Templates
1.1.3 Advanced Templates
1.1.4 Formatter
1.1.5 Constants
1.2 textwrap: Formatting Text Paragraphs
1.2.1 Example Data
1.2.2 Filling Paragraphs
1.2.3 Removing Existing Indentation
1.2.4 Combining Dedent and Fill
1.2.5 Indenting Blocks
1.2.6 Hanging Indents
1.2.7 Truncating Long Text
1.3 re: Regular Expressions
1.3.1 Finding Patterns in Text
1.3.2 Compiling Expressions
1.3.3 Multiple Matches
1.3.4 Pattern Syntax
1.3.5 Constraining the Search
1.3.6 Dissecting Matches with Groups
1.3.7 Search Options
1.3.8 Looking Ahead or Behind
1.3.9 Self-referencing Expressions
1.3.10 Modifying Strings with Patterns
1.3.11 Splitting with Patterns
1.4 difflib: Compare Sequences
1.4.1 Comparing Bodies of Text
1.4.2 Junk Data
1.4.3 Comparing Arbitrary Types
Chapter 2 Data Structures
2.1 enum: Enumeration Type
2.1.1 Creating Enumerations
2.1.2 Iteration
2.1.3 Comparing Enums
2.1.4 Unique Enumeration Values
2.1.5 Creating Enumerations Programmatically
2.1.6 Non-integer Member Values
2.2 collections: Container Data Types
2.2.1 ChainMap: Search Multiple Dictionaries
2.2.2 Counter: Count Hashable Objects
2.2.3 defaultdict: Missing Keys Return a Default Value
2.2.4 deque: Double-Ended Queue
2.2.5 namedtuple: Tuple Subclass with Named Fields
2.2.6 OrderedDict: Remember the Order Keys Are Added to a Dictionary
2.2.7 collections.abc: Abstract Base Classes for Containers
2.3 array: Sequence of Fixed-Type Data
2.3.1 Initialization
2.3.2 Manipulating Arrays
2.3.3 Arrays and Files
2.3.4 Alternative Byte Ordering
2.4 heapq: Heap Sort Algorithm
2.4.1 Example Data
2.4.2 Creating a Heap
2.4.3 Accessing the Contents of a Heap
2.4.4 Data Extremes from a Heap
2.4.5 Efficiently Merging Sorted Sequences
2.5 bisect: Maintain Lists in Sorted Order
2.5.1 Inserting in Sorted Order
2.5.2 Handling Duplicates
2.6 queue: Thread-Safe FIFO Implementation
2.6.1 Basic FIFO Queue
2.6.2 LIFO Queue
2.6.3 Priority Queue
2.6.4 Building a Threaded Podcast Client
2.7 struct: Binary Data Structures
2.7.1 Functions Versus Struct Class
2.7.2 Packing and Unpacking
2.7.3 Endianness
2.7.4 Buffers
2.8 weakref: Impermanent References to Objects
2.8.1 References
2.8.2 Reference Callbacks
2.8.3 Finalizing Objects
2.8.4 Proxies
2.8.5 Caching Objects
2.9 copy: Duplicate Objects
2.9.1 Shallow Copies
2.9.2 Deep Copies
2.9.3 Customizing Copy Behavior
2.9.4 Recursion in Deep Copy
2.10 pprint: Pretty-Print Data Structures
2.10.1 Printing
2.10.2 Formatting
2.10.3 Arbitrary Classes
2.10.4 Recursion
2.10.5 Limiting Nested Output
2.10.6 Controlling Output Width
Chapter 3 Algorithms
3.1 functools: Tools for Manipulating Functions
3.1.1 Decorators
3.1.2 Comparison
3.1.3 Caching
3.1.4 Reducing a Data Set
3.1.5 Generic Functions
3.2 itertools: Iterator Functions
3.2.1 Merging and Splitting Iterators
3.2.2 Converting Inputs
3.2.3 Producing New Values
3.2.4 Filtering
3.2.5 Grouping Data
3.2.6 Combining Inputs
3.3 operator: Functional Interface to Built-in Operators
3.3.1 Logical Operations
3.3.2 Comparison Operators
3.3.3 Arithmetic Operators
3.3.4 Sequence Operators
3.3.5 In-Place Operators
3.3.6 Attribute and Item “Getters”
3.3.7 Combining Operators and Custom Classes
3.4 contextlib: Context Manager Utilities
3.4.1 Context Manager API
3.4.2 Context Managers as Function Decorators
3.4.3 From Generator to Context Manager
3.4.4 Closing Open Handles
3.4.5 Ignoring Exceptions
3.4.6 Redirecting Output Streams
3.4.7 Dynamic Context Manager Stacks
Chapter 4 Dates and Times
4.1 time: Clock Time
4.1.1 Comparing Clocks
4.1.2 Wall Clock Time
4.1.3 Monotonic Clocks
4.1.4 Processor Clock Time
4.1.5 Performance Counter
4.1.6 Time Components
4.1.7 Working with Time Zones
4.1.8 Parsing and Formatting Times
4.2 datetime: Date and Time Value Manipulation
4.2.1 Times
4.2.2 Dates
4.2.3 timedeltas
4.2.4 Date Arithmetic
4.2.5 Comparing Values
4.2.6 Combining Dates and Times
4.2.7 Formatting and Parsing
4.2.8 Time Zones
4.3 calendar: Work with Dates
4.3.1 Formatting Examples
4.3.2 Locales
4.3.3 Calculating Dates
Chapter 5 Mathematics
5.1 decimal: Fixed- and Floating-Point Math
5.1.1 Decimal
5.1.2 Formatting
5.1.3 Arithmetic
5.1.4 Special Values
5.1.5 Context
5.2 fractions: Rational Numbers
5.2.1 Creating Fraction Instances
5.2.2 Arithmetic
5.2.3 Approximating Values
5.3 random: Pseudorandom Number Generators
5.3.1 Generating Random Numbers
5.3.2 Seeding
5.3.3 Saving State
5.3.4 Random Integers
5.3.5 Picking Random Items
5.3.6 Permutations
5.3.7 Sampling
5.3.8 Multiple Simultaneous Generators
5.3.9 SystemRandom
5.3.10 Non-uniform Distributions
5.4 math: Mathematical Functions
5.4.1 Special Constants
5.4.2 Testing for Exceptional Values
5.4.3 Comparing
5.4.4 Converting Floating-Point Values to Integers
5.4.5 Alternative Representations of Floating-Point Values
5.4.6 Positive and Negative Signs
5.4.7 Commonly Used Calculations
5.4.8 Exponents and Logarithms
5.4.9 Angles
5.4.10 Trigonometry
5.4.11 Hyperbolic Functions
5.4.12 Special Functions
5.5 statistics: Statistical Calculations
5.5.1 Averages
5.5.2 Variance
Chapter 6 The File System
6.1 os.path: Platform-Independent Manipulation of Filenames
6.1.1 Parsing Paths
6.1.2 Building Paths
6.1.3 Normalizing Paths
6.1.4 File Times
6.1.5 Testing Files
6.2 pathlib: File System Paths as Objects
6.2.1 Path Representations
6.2.2 Building Paths
6.2.3 Parsing Paths
6.2.4 Creating Concrete Paths
6.2.5 Directory Contents
6.2.6 Reading and Writing Files
6.2.7 Manipulating Directories and Symbolic Links
6.2.8 File Types
6.2.9 File Properties
6.2.10 Permissions
6.2.11 Deleting
6.3 glob: Filename Pattern Matching
6.3.1 Example Data
6.3.2 Wildcards
6.3.3 Single-Character Wildcard
6.3.4 Character Ranges
6.3.5 Escaping Meta-characters
6.4 fnmatch: Unix-Style Glob Pattern Matching
6.4.1 Simple Matching
6.4.2 Filtering
6.4.3 Translating Patterns
6.5 linecache: Read Text Files Efficiently
6.5.1 Test Data
6.5.2 Reading Specific Lines
6.5.3 Handling Blank Lines
6.5.4 Error Handling
6.5.5 Reading Python Source Files
6.6 tempfile: Temporary File System Objects
6.6.1 Temporary Files
6.6.2 Named Files
6.6.3 Spooled Files
6.6.4 Temporary Directories
6.6.5 Predicting Names
6.6.6 Temporary File Location
6.7 shutil: High-Level File Operations
6.7.1 Copying Files
6.7.2 Copying File Metadata
6.7.3 Working with Directory Trees
6.7.4 Finding Files
6.7.5 Archives
6.7.6 File System Space
6.8 filecmp: Compare Files
6.8.1 Example Data
6.8.2 Comparing Files
6.8.3 Comparing Directories
6.8.4 Using Differences in a Program
6.9 mmap: Memory-Map Files
6.9.1 Reading
6.9.2 Writing
6.9.3 Regular Expressions
6.10 codecs: String Encoding and Decoding
6.10.1 Unicode Primer
6.10.2 Working with Files
6.10.3 Byte Order
6.10.4 Error Handling
6.10.5 Encoding Translation
6.10.6 Non-Unicode Encodings
6.10.7 Incremental Encoding
6.10.8 Unicode Data and Network Communication
6.10.9 Defining a Custom Encoding
6.11 io: Text, Binary, and Raw Stream I/O Tools
6.11.1 In-Memory Streams
6.11.2 Wrapping Byte Streams for Text Data
Chapter 7 Data Persistence and Exchange
7.1 pickle: Object Serialization
7.1.1 Encoding and Decoding Data in Strings
7.1.2 Working with Streams
7.1.3 Problems Reconstructing Objects
7.1.4 Unpicklable Objects
7.1.5 Circular References
7.2 shelve: Persistent Storage of Objects
7.2.1 Creating a New Shelf
7.2.2 Writeback
7.2.3 Specific Shelf Types
7.3 dbm: Unix Key–Value Databases
7.3.1 Database Types
7.3.2 Creating a New Database
7.3.3 Opening an Existing Database
7.3.4 Error Cases
7.4 sqlite3: Embedded Relational Database
7.4.1 Creating a Database
7.4.2 Retrieving Data
7.4.3 Query Metadata
7.4.4 Row Objects
7.4.5 Using Variables with Queries
7.4.6 Bulk Loading
7.4.7 Defining New Column Types
7.4.8 Determining Types for Columns
7.4.9 Transactions
7.4.10 Isolation Levels
7.4.11 In-Memory Databases
7.4.12 Exporting the Contents of a Database
7.4.13 Using Python Functions in SQL
7.4.14 Querying with Regular Expressions
7.4.15 Custom Aggregation
7.4.16 Threading and Connection Sharing
7.4.17 Restricting Access to Data
7.5 xml.etree.ElementTree: XML Manipulation API
7.5.1 Parsing an XML Document
7.5.2 Traversing the Parsed Tree
7.5.3 Finding Nodes in a Document
7.5.4 Parsed Node Attributes
7.5.5 Watching Events While Parsing
7.5.6 Creating a Custom Tree Builder
7.5.7 Parsing Strings
7.5.8 Building Documents With Element Nodes
7.5.9 Pretty-Printing XML
7.5.10 Setting Element Properties
7.5.11 Building Trees from Lists of Nodes
7.5.12 Serializing XML to a Stream
7.6 csv: Comma-Separated Value Files
7.6.1 Reading
7.6.2 Writing
7.6.3 Dialects
7.6.4 Using Field Names
Chapter 8 Data Compression and Archiving
8.1 zlib: GNU zlib Compression
8.1.1 Working with Data in Memory
8.1.2 Incremental Compression and Decompression
8.1.3 Mixed Content Streams
8.1.4 Checksums
8.1.5 Compressing Network Data
8.2 gzip: Read and Write GNU zip Files
8.2.1 Writing Compressed Files
8.2.2 Reading Compressed Data
8.2.3 Working with Streams
8.3 bz2: bzip2 Compression
8.3.1 One-Shot Operations in Memory
8.3.2 Incremental Compression and Decompression
8.3.3 Mixed-Content Streams
8.3.4 Writing Compressed Files
8.3.5 Reading Compressed Files
8.3.6 Reading and Writing Unicode Data
8.3.7 Compressing Network Data
8.4 tarfile: Tar Archive Access
8.4.1 Testing Tar Files
8.4.2 Reading Metadata from an Archive
8.4.3 Extracting Files from an Archive
8.4.4 Creating New Archives
8.4.5 Using Alternative Archive Member Names
8.4.6 Writing Data from Sources Other Than Files
8.4.7 Appending to Archives
8.4.8 Working with Compressed Archives
8.5 zipfile: ZIP Archive Access
8.5.1 Testing ZIP Files
8.5.2 Reading Metadata from an Archive
8.5.3 Extracting Archived Files From an Archive
8.5.4 Creating New Archives
8.5.5 Using Alternative Archive Member Names
8.5.6 Writing Data from Sources Other Than Files
8.5.7 Writing with a ZipInfo Instance
8.5.8 Appending to Files
8.5.9 Python ZIP Archives
8.5.10 Limitations
Chapter 9 Cryptography
9.1 hashlib: Cryptographic Hashing
9.1.1 Hash Algorithms
9.1.2 Sample Data
9.1.3 MD5 Example
9.1.4 SHA1 Example
9.1.5 Creating a Hash by Name
9.1.6 Incremental Updates
9.2 hmac: Cryptographic Message Signing and Verification
9.2.1 Signing Messages
9.2.2 Alternative Digest Types
9.2.3 Binary Digests
9.2.4 Applications of Message Signatures
Chapter 10 Concurrency with Processes, Threads, and Coroutines
10.1 subprocess: Spawning Additional Processes
10.1.1 Running External Command
10.1.2 Working with Pipes Directly
10.1.3 Connecting Segments of a Pipe
10.1.4 Interacting with Another Command
10.1.5 Signaling Between Processes
10.2 signal: Asynchronous System Events
10.2.1 Receiving Signals
10.2.2 Retrieving Registered Handlers
10.2.3 Sending Signals
10.2.4 Alarms
10.2.5 Ignoring Signals
10.2.6 Signals and Threads
10.3 threading: Manage Concurrent Operations Within a Process
10.3.1 Thread Objects
10.3.2 Determining the Current Thread
10.3.3 Daemon Versus Non-daemon Threads
10.3.4 Enumerating All Threads
10.3.5 Subclassing Thread
10.3.6 Timer Threads
10.3.7 Signaling Between Threads
10.3.8 Controlling Access to Resources
10.3.9 Synchronizing Threads
10.3.10 Limiting Concurrent Access to Resources
10.3.11 Thread Specific Data
10.4 multiprocessing: Manage Processes Like Threads
10.4.1 multiprocessing Basics
10.4.2 Importable Target Functions
10.4.3 Determining the Current Process
10.4.4 Daemon Processes
10.4.5 Waiting for Processes
10.4.6 Terminating Processes
10.4.7 Process Exit Status
10.4.8 Logging
10.4.9 Subclassing Process
10.4.10 Passing Messages to Processes
10.4.11 Signaling Between Processes
10.4.12 Controlling Access to Resources
10.4.13 Synchronizing Operations
10.4.14 Controlling Concurrent Access to Resources
10.4.15 Managing Shared State
10.4.16 Shared Namespaces
10.4.17 Process Pools
10.4.18 Implementing MapReduce
10.5 asyncio: Asynchronous I/O, Event Loop, and Concurrency Tools
10.5.1 Asynchronous Concurrency Concepts
10.5.2 Cooperative Multitasking with Coroutines
10.5.3 Scheduling Calls to Regular Functions
10.5.4 Producing Results Asynchronously
10.5.5 Executing Tasks Concurrently
10.5.6 Composing Coroutines with Control Structures
10.5.7 Synchronization Primitives
10.5.8 Asynchronous I/O with Protocol Class Abstractions
10.5.9 Asynchronous I/O Using Coroutines and Streams
10.5.10 Using SSL
10.5.11 Interacting with Domain Name Services
10.5.12 Working with Subprocesses
10.5.13 Receiving Unix Signals
10.5.14 Combining Coroutines with Threads and Processes
10.5.15 Debugging with asyncio
10.6 concurrent.futures: Manage Pools of Concurrent Tasks
10.6.1 Using map() with a Basic Thread Pool
10.6.2 Scheduling Individual Tasks
10.6.3 Waiting for Tasks in Any Order
10.6.4 Future Callbacks
10.6.5 Canceling Tasks
10.6.6 Exceptions in Tasks
10.6.7 Context Manager
10.6.8 Process Pools
Chapter 11 Networking
11.1 ipaddress: Internet Addresses
11.1.1 Addresses
11.1.2 Networks
11.1.3 Interfaces
11.2 socket: Network Communication
11.2.1 Addressing, Protocol Families, and Socket Types
11.2.2 TCP/IP Client and Server
11.2.3 User Datagram Client and Server
11.2.4 Unix Domain Sockets
11.2.5 Multicast
11.2.6 Sending Binary Data
11.2.7 Non-blocking Communication and Timeouts
11.3 selectors: I/O Multiplexing Abstractions
11.3.1 Operating Model
11.3.2 Echo Server
11.3.3 Echo Client
11.3.4 Server and Client Together
11.4 select: Wait for I/O Efficiently
11.4.1 Using select()
11.4.2 Non-blocking I/O with Timeouts
11.4.3 Using poll()
11.4.4 Platform-Specific Options
11.5 socketserver: Creating Network Servers
11.5.1 Server Types
11.5.2 Server Objects
11.5.3 Implementing a Server
11.5.4 Request Handlers
11.5.5 Echo Example
11.5.6 Threading and Forking
Chapter 12 The Internet
12.1 urllib.parse: Split URLs into Components
12.1.1 Parsing
12.1.2 Unparsing
12.1.3 Joining
12.1.4 Encoding Query Arguments
12.2 urllib.request: Network Resource Access
12.2.1 HTTP GET
12.2.2 Encoding Arguments
12.2.3 HTTP POST
12.2.4 Adding Outgoing Headers
12.2.5 Posting Form Data from a Request
12.2.6 Uploading Files
12.2.7 Creating Custom Protocol Handlers
12.3 urllib.robotparser: Internet Spider Access Control
12.3.1 robots.txt
12.3.2 Testing Access Permissions
12.3.3 Long-Lived Spiders
12.4 base64: Encode Binary Data with ASCII
12.4.1 Base 64 Encoding
12.4.2 Base64 Decoding
12.4.3 URL-Safe Variations
12.4.4 Other Encodings
12.5 http.server: Base Classes for Implementing Web Servers
12.5.1 HTTP GET
12.5.2 HTTP POST
12.5.3 Threading and Forking
12.5.4 Handling Errors
12.5.5 Setting Headers
12.5.6 Command-Line Use
12.6 http.cookies: HTTP Cookies
12.6.1 Creating and Setting a Cookie
12.6.2 Morsels
12.6.3 Encoded Values
12.6.4 Receiving and Parsing Cookie Headers
12.6.5 Alternative Output Formats
12.7 webbrowser: Displays Web Pages
12.7.1 Simple Example
12.7.2 Windows Versus Tabs
12.7.3 Using a Specific Browser
12.7.4 BROWSER Variable
12.7.5 Command-Line Interface
12.8 uuid: Universally Unique Identifiers
12.8.1 UUID 1: IEEE 802 MAC Address
12.8.2 UUID 3 and 5: Name-Based Values
12.8.3 UUID 4: Random Values
12.8.4 Working with UUID Objects
12.9 json: JavaScript Object Notation
12.9.1 Encoding and Decoding Simple Data Types
12.9.2 Human-Consumable Versus Compact Output
12.9.3 Encoding Dictionaries
12.9.4 Working with Custom Types
12.9.5 Encoder and Decoder Classes
12.9.6 Working with Streams and Files
12.9.7 Mixed Data Streams
12.9.8 JSON at the Command Line
12.10 xmlrpc.client: Client Library for XML-RPC
12.10.1 Connecting to a Server
12.10.2 Data Types
12.10.3 Passing Objects
12.10.4 Binary Data
12.10.5 Exception Handling
12.10.6 Combining Calls into One Message
12.11 xmlrpc.server: An XML-RPC Server
12.11.1 A Simple Server
12.11.2 Alternate API Names
12.11.3 Dotted API Names
12.11.4 Arbitrary API Names
12.11.5 Exposing Methods of Objects
12.11.6 Dispatching Calls
12.11.7 Introspection API
Chapter 13 Email
13.1 smtplib: Simple Mail Transfer Protocol Client
13.1.1 Sending an Email Message
13.1.2 Authentication and Encryption
13.1.3 Verifying an Email Address
13.2 smtpd: Sample Mail Servers
13.2.1 Mail Server Base Class
13.2.2 Debugging Server
13.2.3 Proxy Server
13.3 mailbox: Manipulate Email Archives
13.3.1 mbox
13.3.2 Maildir
13.3.3 Message Flags
13.3.4 Other Formats
13.4 imaplib: IMAP4 Client Library
13.4.1 Variations
13.4.2 Connecting to a Server
13.4.3 Example Configuration
13.4.4 Listing Mailboxes
13.4.5 Mailbox Status
13.4.6 Selecting a Mailbox
13.4.7 Searching for Messages
13.4.8 Search Criteria
13.4.9 Fetching Messages
13.4.10 Whole Messages
13.4.11 Uploading Messages
13.4.12 Moving and Copying Messages
13.4.13 Deleting Messages
Chapter 14 Application Building Blocks
14.1 argparse: Command-Line Option and Argument Parsing
14.1.1 Setting Up a Parser
14.1.2 Defining Arguments
14.1.3 Parsing a Command Line
14.1.4 Simple Examples
14.1.5 Help Output
14.1.6 Parser Organization
14.1.7 Advanced Argument Processing
14.2 getopt: Command-Line Option Parsing
14.2.1 Function Arguments
14.2.2 Short-Form Options
14.2.3 Long-Form Options
14.2.4 A Complete Example
14.2.5 Abbreviating Long-Form Options
14.2.6 GNU-Style Option Parsing
14.2.7 Ending Argument Processing
14.3 readline: The GNU readline Library
14.3.1 Configuring readline
14.3.2 Completing Text
14.3.3 Accessing the Completion Buffer
14.3.4 Input History
14.3.5 Hooks
14.4 getpass: Secure Password Prompt
14.4.1 Example
14.4.2 Using getpass Without a Terminal
14.5 cmd: Line-Oriented Command Processors
14.5.1 Processing Commands
14.5.2 Command Arguments
14.5.3 Live Help
14.5.4 Auto-Completion
14.5.5 Overriding Base Class Methods
14.5.6 Configuring Cmd Through Attributes
14.5.7 Running Shell Commands
14.5.8 Alternative Inputs
14.5.9 Commands from sys.argv
14.6 shlex: Parse Shell-Style Syntaxes
14.6.1 Parsing Quoted Strings
14.6.2 Making Safe Strings for Shells
14.6.3 Embedded Comments
14.6.4 Splitting Strings into Tokens
14.6.5 Including Other Sources of Tokens
14.6.6 Controlling the Parser
14.6.7 Error Handling
14.6.8 POSIX Versus Non-POSIX Parsing
14.7 configparser: Work with Configuration Files
14.7.1 Configuration File Format
14.7.2 Reading Configuration Files
14.7.3 Accessing Configuration Settings
14.7.4 Modifying Settings
14.7.5 Saving Configuration Files
14.7.6 Option Search Path
14.7.7 Combining Values with Interpolation
14.8 logging: Report Status, Error, and Informational Messages
14.8.1 Logging Components
14.8.2 Logging in Applications Versus Libraries
14.8.3 Logging to a File
14.8.4 Rotating Log Files
14.8.5 Verbosity Levels
14.8.6 Naming Logger Instances
14.8.7 The Logging Tree
14.8.8 Integration with the warnings Module
14.9 fileinput: Command-Line Filter Framework
14.9.1 Converting M3U Files to RSS
14.9.2 Progress Metadata
14.9.3 In-Place Filtering
14.10 atexit: Program Shutdown Callbacks
14.10.1 Registering Exit Callbacks
14.10.2 Decorator Syntax
14.10.3 Canceling Callbacks
14.10.4 When Are atexit Callbacks Not Called?
14.10.5 Handling Exceptions
14.11 sched: Timed Event Scheduler
14.11.1 Running Events with a Delay
14.11.2 Overlapping Events
14.11.3 Event Priorities
14.11.4 Canceling Events
Chapter 15 Internationalization and Localization
15.1 gettext: Message Catalogs
15.1.1 Translation Workflow Overview
15.1.2 Creating Message Catalogs from Source Code
15.1.3 Finding Message Catalogs at Runtime
15.1.4 Plural Values
15.1.5 Application Versus Module Localization
15.1.6 Switching Translations
15.2 locale: Cultural Localization API
15.2.1 Probing the Current Locale
15.2.2 Currency
15.2.3 Formatting Numbers
15.2.4 Parsing Numbers
15.2.5 Dates and Times
Chapter 16 Developer Tools
16.1 pydoc: Online Help for Modules
16.1.1 Plain Text Help
16.1.2 HTML Help
16.1.3 Interactive Help
16.2 doctest: Testing Through Documentation
16.2.1 Getting Started
16.2.2 Handling Unpredictable Output
16.2.3 Tracebacks
16.2.4 Working Around Whitespace
16.2.5 Test Locations
16.2.6 External Documentation
16.2.7 Running Tests
16.2.8 Test Context
16.3 unittest: Automated Testing Framework
16.3.1 Basic Test Structure
16.3.2 Running Tests
16.3.3 Test Outcomes
16.3.4 Asserting Truth
16.3.5 Testing Equality
16.3.6 Almost Equal?
16.3.7 Containers
16.3.8 Testing for Exceptions
16.3.9 Test Fixtures
16.3.10 Repeating Tests with Different Inputs
16.3.11 Skipping Tests
16.3.12 Ignoring Failing Tests
16.4 trace: Follow Program Flow
16.4.1 Example Program
16.4.2 Tracing Execution
16.4.3 Code Coverage
16.4.4 Calling Relationships
16.4.5 Programming Interface
16.4.6 Saving Result Data
16.4.7 Options
16.5 traceback: Exceptions and Stack Traces
16.5.1 Supporting Functions
16.5.2 Examining the Stack
16.5.3 TracebackException
16.5.4 Low-Level Exception APIs
16.5.5 Low-Level Stack APIs
16.6 cgitb: Detailed Traceback Reports
16.6.1 Standard Traceback Dumps
16.6.2 Enabling Detailed Tracebacks
16.6.3 Local Variables in Tracebacks
16.6.4 Exception Properties
16.6.5 HTML Output
16.6.6 Logging Tracebacks
16.7 pdb: Interactive Debugger
16.7.1 Starting the Debugger
16.7.2 Controlling the Debugger
16.7.3 Breakpoints
16.7.4 Changing Execution Flow
16.7.5 Customizing the Debugger with Aliases
16.7.6 Saving Configuration Settings
16.8 profile and pstats: Performance Analysis
16.8.1 Running the Profiler
16.8.2 Running in a Context
16.8.3 pstats: Saving and Working with Statistics
16.8.4 Limiting Report Contents
16.8.5 Caller/Callee Graphs
16.9 timeit: Time the Execution of Small Bits of Python Code
16.9.1 Module Contents
16.9.2 Basic Example
16.9.3 Storing Values in a Dictionary
16.9.4 From the Command Line
16.10 tabnanny: Indentation Validator
16.10.1 Running from the Command Line
16.11 compileall: Byte-Compile Source Files
16.11.1 Compiling One Directory
16.11.2 Ignoring Files
16.11.3 Compiling sys.path
16.11.4 Compiling Individual Files
16.11.5 From the Command Line
16.12 pyclbr: Class Browser
16.12.1 Scanning for Classes
16.12.2 Scanning for Functions
16.13 venv: Create Virtual Environments
16.13.1 Creating Environments
16.13.2 Contents of a Virtual Environment
16.13.3 Using Virtual Environments
16.14 ensurepip: Install the Python Package Installer
16.14.1 Installing pip
Chapter 17 Runtime Features
17.1 site: Site-wide Configuration
17.1.1 Import Path
17.1.2 User Directories
17.1.3 Path Configuration Files
17.1.4 Customizing Site Configuration
17.1.5 Customizing User Configuration
17.1.6 Disabling the site Module
17.2 sys: System-Specific Configuration
17.2.1 Interpreter Settings
17.2.2 Runtime Environment
17.2.3 Memory Management and Limits
17.2.4 Exception Handling
17.2.5 Low-Level Thread Support
17.2.6 Modules and Imports
17.2.7 Tracing a Program As It Runs
17.3 os: Portable Access to Operating System–Specific Features
17.3.1 Examining the File System Contents
17.3.2 Managing File System Permissions
17.3.3 Creating and Deleting Directories
17.3.4 Working with Symbolic Links
17.3.5 Safely Replacing an Existing File
17.3.6 Detecting and Changing the Process Owner
17.3.7 Managing the Process Environment
17.3.8 Managing the Process Working Directory
17.3.9 Running External Commands
17.3.10 Creating Processes with os.fork()
17.3.11 Waiting for Child Processes
17.3.12 Spawning New Processes
17.3.13 Operating System Error Codes
17.4 platform: System Version Information
17.4.1 Interpreter
17.4.2 Platform
17.4.3 Operating System and Hardware Information
17.4.4 Executable Architecture
17.5 resource: System Resource Management
17.5.1 Current Usage
17.5.2 Resource Limits
17.6 gc: Garbage Collector
17.6.1 Tracing References
17.6.2 Forcing Garbage Collection
17.6.3 Finding References to Objects That Cannot Be Collected
17.6.4 Collection Thresholds and Generations
17.6.5 Debugging
17.7 sysconfig: Interpreter Compile-Time Configuration
17.7.1 Configuration Variables
17.7.2 Installation Paths
17.7.3 Python Version and Platform
Chapter 18 Language Tools
18.1 warnings: Non-fatal Alerts
18.1.1 Categories and Filtering
18.1.2 Generating Warnings
18.1.3 Filtering with Patterns
18.1.4 Repeated Warnings
18.1.5 Alternative Message Delivery Functions
18.1.6 Formatting
18.1.7 Stack Level in Warnings
18.2 abc: Abstract Base Classes
18.2.1 How ABCs Work
18.2.2 Registering a Concrete Class
18.2.3 Implementation Through Subclassing
18.2.4 Helper Base Class
18.2.5 Incomplete Implementations
18.2.6 Concrete Methods in ABCs
18.2.7 Abstract Properties
18.2.8 Abstract Class and Static Methods
18.3 dis: Python Byte-Code Disassembler
18.3.1 Basic Disassembly
18.3.2 Disassembling Functions
18.3.3 Classes
18.3.4 Source Code
18.3.5 Using Disassembly to Debug
18.3.6 Performance Analysis of Loops
18.3.7 Compiler Optimizations
18.4 inspect: Inspect Live Objects
18.4.1 Example Module
18.4.2 Inspecting Modules
18.4.3 Inspecting Classes
18.4.4 Inspecting Instances
18.4.5 Documentation Strings
18.4.6 Retrieving Source
18.4.7 Method and Function Signatures
18.4.8 Class Hierarchies
18.4.9 Method Resolution Order
18.4.10 The Stack and Frames
18.4.11 Command-Line Interface
Chapter 19 Modules and Packages
19.1 importlib: Python’s Import Mechanism
19.1.1 Example Package
19.1.2 Module Types
19.1.3 Importing Modules
19.1.4 Loaders
19.2 pkgutil: Package Utilities
19.2.1 Package Import Paths
19.2.2 Development Versions of Packages
19.2.3 Managing Paths with PKG Files
19.2.4 Nested Packages
19.2.5 Package Data
19.3 zipimport: Load Python Code from ZIP Archives
19.3.1 Example
19.3.2 Finding a Module
19.3.3 Accessing Code
19.3.4 Source
19.3.5 Packages
19.3.6 Data
Appendix A: Porting Notes
A.1 References
A.2 New Modules
A.3 Renamed Modules
A.4 Removed Modules
A.4.1 bsddb
A.4.2 commands
A.4.3 compiler
A.4.4 dircache
A.4.5 EasyDialogs
A.4.6 exceptions
A.4.7 htmllib
A.4.8 md5
A.4.9 mimetools, MimeWriter, mimify, multifile, and rfc822
A.4.10 popen2
A.4.11 posixfile
A.4.12 sets
A.4.13 sha
A.4.14 sre
A.4.15 statvfs
A.4.16 thread
A.4.17 user
A.5 Deprecated Modules
A.5.1 asyncore and asynchat
A.5.2 formatter
A.5.3 imp
A.5.4 optparse
A.6 Summary of Changes to Modules
A.6.1 abc
A.6.2 anydbm
A.6.3 argparse
A.6.4 array
A.6.5 atexit
A.6.6 base64
A.6.7 bz2
A.6.8 collections
A.6.9 comands
A.6.10 configparser
A.6.11 contextlib
A.6.12 csv
A.6.13 datetime
A.6.14 decimal
A.6.15 fractions
A.6.16 gc
A.6.17 gettext
A.6.18 glob
A.6.19 http.cookies
A.6.20 imaplib
A.6.21 inspect
A.6.22 itertools
A.6.23 json
A.6.24 locale
A.6.25 logging
A.6.26 mailbox
A.6.27 mmap
A.6.28 operator
A.6.29 os
A.6.30 os.path
A.6.31 pdb
A.6.32 pickle
A.6.33 pipes
A.6.34 platform
A.6.35 random
A.6.36 re
A.6.37 shelve
A.6.38 signal
A.6.39 socket
A.6.40 socketserver
A.6.41 string
A.6.42 struct
A.6.43 subprocess
A.6.44 sys
A.6.45 threading
A.6.46 time
A.6.47 unittest
A.6.48 UserDict, UserList, and UserString
A.6.49 uuid
A.6.50 whichdb
A.6.51 xml.etree.ElementTree
A.6.52 zipimport
Appendix B: Outside of the Standard Library
B.1 Text
B.2 Algorithms
B.3 Dates and Times
B.4 Mathematics
B.5 Data Persistence and Exchange
B.6 Cryptography
B.7 Concurrency with Processes, Threads, and Coroutines
B.8 The Internet
B.9 Email
B.10 Application Building Blocks
B.11 Developer Tools
Index of Python Modules
A
B
C
D
E
F
G
H
I
J
L
M
O
P
Q
R
S
T
U
V
W
X
Z
Index
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z