Python报错‘invalid escape sequence’和‘No module named wordcloud’该怎么修?

### Python 中 SyntaxWarning 警告和 ModuleNotFoundError 错误解决方案 #### 解决 `SyntaxWarning` 警告 当遇到 `invalid escape sequence` 的警告时,通常是因为在字符串中使用了反斜杠 `\` 后跟了一个非法字符组合。Python 将此视为潜在的转义序列错误[^1]。 以下是修复方法之一:如果确实不需要转义字符,则可以将字符串标记为原始字符串 (raw string),通过在其前加上字母 `r` 来实现: ```python path = r"C:\Users\Example" ``` 另一种方式是对反斜杠进行双重转义,即使用双反斜杠代替单个反斜杠来消除该警告: ```python path = "C:\\Users\\Example" ``` #### 解决 `ModuleNotFoundError` 错误 对于 `No module named 'wordcloud'` 这类模块未找到的错误,通常是由于目标库尚未安装或者环境配置不正确引起的。要解决这个问题,可以通过 pip 安装所需的库[^2]: 运行以下命令以安装缺失的模块: ```bash pip install wordcloud ``` 确认虚拟环境中已激活正确的解释器版本也很重要,因为不同的 Python 版本可能对应着独立的包管理空间。如果是在 Jupyter Notebook 或其他 IDE 下工作,请确保所使用的 kernel 已经加载了相应的依赖项。 另外需要注意的是,在某些情况下,即使已经成功安装了某个第三方库,但如果项目目录下存在名为 `wordcloud.py` 的文件或其他同名脚本,可能会引发命名冲突并阻止实际外部库被导入。此时应重命名本地干扰文件或将它们移除后再尝试重新执行程序[^3]。 ```python import wordcloud print(wordcloud.__version__) ``` 上述代码用于验证是否能够正常引入 WordCloud 库及其版本号信息。

创作声明:本文部分内容由AI辅助生成(AIGC),仅供参考

Python内容推荐

Python常用英文单词

Python常用英文单词

Python常用英文单词

python3.6.5参考手册 chm

python3.6.5参考手册 chm

Python参考手册,官方正式版参考手册,chm版。以下摘取部分内容:Navigation index modules | next | Python » 3.6.5 Documentation » Python Documentation contents What’s New in Python What’s New In Python 3.6 Summary – Release highlights New Features PEP 498: Formatted string literals PEP 526: Syntax for variable annotations PEP 515: Underscores in Numeric Literals PEP 525: Asynchronous Generators PEP 530: Asynchronous Comprehensions PEP 487: Simpler customization of class creation PEP 487: Descriptor Protocol Enhancements PEP 519: Adding a file system path protocol PEP 495: Local Time Disambiguation PEP 529: Change Windows filesystem encoding to UTF-8 PEP 528: Change Windows console encoding to UTF-8 PEP 520: Preserving Class Attribute Definition Order PEP 468: Preserving Keyword Argument Order New dict implementation PEP 523: Adding a frame evaluation API to CPython PYTHONMALLOC environment variable DTrace and SystemTap probing support Other Language Changes New Modules secrets Improved Modules array ast asyncio binascii cmath collections concurrent.futures contextlib datetime decimal distutils email encodings enum faulthandler fileinput hashlib http.client idlelib and IDLE importlib inspect json logging math multiprocessing os pathlib pdb pickle pickletools pydoc random re readline rlcompleter shlex site sqlite3 socket socketserver ssl statistics struct subprocess sys telnetlib time timeit tkinter traceback tracemalloc typing unicodedata unittest.mock urllib.request urllib.robotparser venv warnings winreg winsound xmlrpc.client zipfile zlib Optimizations Build and C API Changes Other Improvements Deprecated New Keywords Deprecated Python behavior Deprecated Python modules, functions and methods asynchat asyncore dbm distutils grp importlib os re ssl tkinter venv Deprecated functions and types of the C API Deprecated Build Options Removed API and Feature Removals Porting to Python 3.6 Changes in ‘python’ Command Behavior Changes in the Python API Changes in the C API CPython bytecode changes Notable changes in Python 3.6.2 New make regen-all build target Removal of make touch build target Notable changes in Python 3.6.5 What’s New In Python 3.5 Summary – Release highlights New Features PEP 492 - Coroutines with async and await syntax PEP 465 - A dedicated infix operator for matrix multiplication PEP 448 - Additional Unpacking Generalizations PEP 461 - percent formatting support for bytes and bytearray PEP 484 - Type Hints PEP 471 - os.scandir() function – a better and faster directory iterator PEP 475: Retry system calls failing with EINTR PEP 479: Change StopIteration handling inside generators PEP 485: A function for testing approximate equality PEP 486: Make the Python Launcher aware of virtual environments PEP 488: Elimination of PYO files PEP 489: Multi-phase extension module initialization Other Language Changes New Modules typing zipapp Improved Modules argparse asyncio bz2 cgi cmath code collections collections.abc compileall concurrent.futures configparser contextlib csv curses dbm difflib distutils doctest email enum faulthandler functools glob gzip heapq http http.client idlelib and IDLE imaplib imghdr importlib inspect io ipaddress json linecache locale logging lzma math multiprocessing operator os pathlib pickle poplib re readline selectors shutil signal smtpd smtplib sndhdr socket ssl Memory BIO Support Application-Layer Protocol Negotiation Support Other Changes sqlite3 subprocess sys sysconfig tarfile threading time timeit tkinter traceback types unicodedata unittest unittest.mock urllib wsgiref xmlrpc xml.sax zipfile Other module-level changes Optimizations Build and C API Changes Deprecated New Keywords Deprecated Python Behavior Unsupported Operating Systems Deprecated Python modules, functions and methods Removed API and Feature Removals Porting to Python 3.5 Changes in Python behavior Changes in the Python API Changes in the C API What’s New In Python 3.4 Summary – Release Highlights New Features PEP 453: Explicit Bootstrapping of PIP in Python Installations Bootstrapping pip By Default Documentation Changes PEP 446: Newly Created File Descriptors Are Non-Inheritable Improvements to Codec Handling PEP 451: A ModuleSpec Type for the Import System Other Language Changes New Modules asyncio ensurepip enum pathlib selectors statistics tracemalloc Improved Modules abc aifc argparse audioop base64 collections colorsys contextlib dbm dis doctest email filecmp functools gc glob hashlib hmac html http idlelib and IDLE importlib inspect ipaddress logging marshal mmap multiprocessing operator os pdb pickle plistlib poplib pprint pty pydoc re resource select shelve shutil smtpd smtplib socket sqlite3 ssl stat struct subprocess sunau sys tarfile textwrap threading traceback types urllib unittest venv wave weakref xml.etree zipfile CPython Implementation Changes PEP 445: Customization of CPython Memory Allocators PEP 442: Safe Object Finalization PEP 456: Secure and Interchangeable Hash Algorithm PEP 436: Argument Clinic Other Build and C API Changes Other Improvements Significant Optimizations Deprecated Deprecations in the Python API Deprecated Features Removed Operating Systems No Longer Supported API and Feature Removals Code Cleanups Porting to Python 3.4 Changes in ‘python’ Command Behavior Changes in the Python API Changes in the C API Changed in 3.4.3 PEP 476: Enabling certificate verification by default for stdlib http clients What’s New In Python 3.3 Summary – Release highlights PEP 405: Virtual Environments PEP 420: Implicit Namespace Packages PEP 3118: New memoryview implementation and buffer protocol documentation Features API changes PEP 393: Flexible String Representation Functionality Performance and resource usage PEP 397: Python Launcher for Windows PEP 3151: Reworking the OS and IO exception hierarchy PEP 380: Syntax for Delegating to a Subgenerator PEP 409: Suppressing exception context PEP 414: Explicit Unicode literals PEP 3155: Qualified name for classes and functions PEP 412: Key-Sharing Dictionary PEP 362: Function Signature Object PEP 421: Adding sys.implementation SimpleNamespace Using importlib as the Implementation of Import New APIs Visible Changes Other Language Changes A Finer-Grained Import Lock Builtin functions and types New Modules faulthandler ipaddress lzma Improved Modules abc array base64 binascii bz2 codecs collections contextlib crypt curses datetime decimal Features API changes email Policy Framework Provisional Policy with New Header API Other API Changes ftplib functools gc hmac http html imaplib inspect io itertools logging math mmap multiprocessing nntplib os pdb pickle pydoc re sched select shlex shutil signal smtpd smtplib socket socketserver sqlite3 ssl stat struct subprocess sys tarfile tempfile textwrap threading time types unittest urllib webbrowser xml.etree.ElementTree zlib Optimizations Build and C API Changes Deprecated Unsupported Operating Systems Deprecated Python modules, functions and methods Deprecated functions and types of the C API Deprecated features Porting to Python 3.3 Porting Python code Porting C code Building C extensions Command Line Switch Changes What’s New In Python 3.2 PEP 384: Defining a Stable ABI PEP 389: Argparse Command Line Parsing Module PEP 391: Dictionary Based Configuration for Logging PEP 3148: The concurrent.futures module PEP 3147: PYC Repository Directories PEP 3149: ABI Version Tagged .so Files PEP 3333: Python Web Server Gateway Interface v1.0.1 Other Language Changes New, Improved, and Deprecated Modules email elementtree functools itertools collections threading datetime and time math abc io reprlib logging csv contextlib decimal and fractions ftp popen select gzip and zipfile tarfile hashlib ast os shutil sqlite3 html socket ssl nntp certificates imaplib http.client unittest random poplib asyncore tempfile inspect pydoc dis dbm ctypes site sysconfig pdb configparser urllib.parse mailbox turtledemo Multi-threading Optimizations Unicode Codecs Documentation IDLE Code Repository Build and C API Changes Porting to Python 3.2 What’s New In Python 3.1 PEP 372: Ordered Dictionaries PEP 378: Format Specifier for Thousands Separator Other Language Changes New, Improved, and Deprecated Modules Optimizations IDLE Build and C API Changes Porting to Python 3.1 What’s New In Python 3.0 Common Stumbling Blocks Print Is A Function Views And Iterators Instead Of Lists Ordering Comparisons Integers Text Vs. Data Instead Of Unicode Vs. 8-bit Overview Of Syntax Changes New Syntax Changed Syntax Removed Syntax Changes Already Present In Python 2.6 Library Changes PEP 3101: A New Approach To String Formatting Changes To Exceptions Miscellaneous Other Changes Operators And Special Methods Builtins Build and C API Changes Performance Porting To Python 3.0 What’s New in Python 2.7 The Future for Python 2.x Changes to the Handling of Deprecation Warnings Python 3.1 Features PEP 372: Adding an Ordered Dictionary to collections PEP 378: Format Specifier for Thousands Separator PEP 389: The argparse Module for Parsing Command Lines PEP 391: Dictionary-Based Configuration For Logging PEP 3106: Dictionary Views PEP 3137: The memoryview Object Other Language Changes Interpreter Changes Optimizations New and Improved Modules New module: importlib New module: sysconfig ttk: Themed Widgets for Tk Updated module: unittest Updated module: ElementTree 1.3 Build and C API Changes Capsules Port-Specific Changes: Windows Port-Specific Changes: Mac OS X Port-Specific Changes: FreeBSD Other Changes and Fixes Porting to Python 2.7 New Features Added to Python 2.7 Maintenance Releases PEP 434: IDLE Enhancement Exception for All Branches PEP 466: Network Security Enhancements for Python 2.7 Acknowledgements What’s New in Python 2.6 Python 3.0 Changes to the Development Process New Issue Tracker: Roundup New Documentation Format: reStructuredText Using Sphinx PEP 343: The ‘with’ statement Writing Context Managers The contextlib module PEP 366: Explicit Relative Imports From a Main Module PEP 370: Per-user site-packages Directory PEP 371: The multiprocessing Package PEP 3101: Advanced String Formatting PEP 3105: print As a Function PEP 3110: Exception-Handling Changes PEP 3112: Byte Literals PEP 3116: New I/O Library PEP 3118: Revised Buffer Protocol PEP 3119: Abstract Base Classes PEP 3127: Integer Literal Support and Syntax PEP 3129: Class Decorators PEP 3141: A Type Hierarchy for Numbers The fractions Module Other Language Changes Optimizations Interpreter Changes New and Improved Modules The ast module The future_builtins module The json module: JavaScript Object Notation The plistlib module: A Property-List Parser ctypes Enhancements Improved SSL Support Deprecations and Removals Build and C API Changes Port-Specific Changes: Windows Port-Specific Changes: Mac OS X Port-Specific Changes: IRIX Porting to Python 2.6 Acknowledgements What’s New in Python 2.5 PEP 308: Conditional Expressions PEP 309: Partial Function Application PEP 314: Metadata for Python Software Packages v1.1 PEP 328: Absolute and Relative Imports PEP 338: Executing Modules as Scripts PEP 341: Unified try/except/finally PEP 342: New Generator Features PEP 343: The ‘with’ statement Writing Context Managers The contextlib module PEP 352: Exceptions as New-Style Classes PEP 353: Using ssize_t as the index type PEP 357: The ‘__index__’ method Other Language Changes Interactive Interpreter Changes Optimizations New, Improved, and Removed Modules The ctypes package The ElementTree package The hashlib package The sqlite3 package The wsgiref package Build and C API Changes Port-Specific Changes Porting to Python 2.5 Acknowledgements What’s New in Python 2.4 PEP 218: Built-In Set Objects PEP 237: Unifying Long Integers and Integers PEP 289: Generator Expressions PEP 292: Simpler String Substitutions PEP 318: Decorators for Functions and Methods PEP 322: Reverse Iteration PEP 324: New subprocess Module PEP 327: Decimal Data Type Why is Decimal needed? The Decimal type The Context type PEP 328: Multi-line Imports PEP 331: Locale-Independent Float/String Conversions Other Language Changes Optimizations New, Improved, and Deprecated Modules cookielib doctest Build and C API Changes Port-Specific Changes Porting to Python 2.4 Acknowledgements What’s New in Python 2.3 PEP 218: A Standard Set Datatype PEP 255: Simple Generators PEP 263: Source Code Encodings PEP 273: Importing Modules from ZIP Archives PEP 277: Unicode file name support for Windows NT PEP 278: Universal Newline Support PEP 279: enumerate() PEP 282: The logging Package PEP 285: A Boolean Type PEP 293: Codec Error Handling Callbacks PEP 301: Package Index and Metadata for Distutils PEP 302: New Import Hooks PEP 305: Comma-separated Files PEP 307: Pickle Enhancements Extended Slices Other Language Changes String Changes Optimizations New, Improved, and Deprecated Modules Date/Time Type The optparse Module Pymalloc: A Specialized Object Allocator Build and C API Changes Port-Specific Changes Other Changes and Fixes Porting to Python 2.3 Acknowledgements What’s New in Python 2.2 Introduction PEPs 252 and 253: Type and Class Changes Old and New Classes Descriptors Multiple Inheritance: The Diamond Rule Attribute Access Related Links PEP 234: Iterators PEP 255: Simple Generators PEP 237: Unifying Long Integers and Integers PEP 238: Changing the Division Operator Unicode Changes PEP 227: Nested Scopes New and Improved Modules Interpreter Changes and Fixes Other Changes and Fixes Acknowledgements What’s New in Python 2.1 Introduction PEP 227: Nested Scopes PEP 236: __future__ Directives PEP 207: Rich Comparisons PEP 230: Warning Framework PEP 229: New Build System PEP 205: Weak References PEP 232: Function Attributes PEP 235: Importing Modules on Case-Insensitive Platforms PEP 217: Interactive Display Hook PEP 208: New Coercion Model PEP 241: Metadata in Python Packages New and Improved Modules Other Changes and Fixes Acknowledgements What’s New in Python 2.0 Introduction What About Python 1.6? New Development Process Unicode List Comprehensions Augmented Assignment String Methods Garbage Collection of Cycles Other Core Changes Minor Language Changes Changes to Built-in Functions Porting to 2.0 Extending/Embedding Changes Distutils: Making Modules Easy to Install XML Modules SAX2 Support DOM Support Relationship to PyXML Module changes New modules IDLE Improvements Deleted and Deprecated Modules Acknowledgements Changelog Python 3.6.5 final? Tests Build Python 3.6.5 release candidate 1? Security Core and Builtins Library Documentation Tests Build Windows macOS IDLE Tools/Demos C API Python 3.6.4 final? Python 3.6.4 release candidate 1? Core and Builtins Library Documentation Tests Build Windows macOS IDLE Tools/Demos C API Python 3.6.3 final? Library Build Python 3.6.3 release candidate 1? Security Core and Builtins Library Documentation Tests Build Windows IDLE Tools/Demos Python 3.6.2 final? Python 3.6.2 release candidate 2? Security Python 3.6.2 release candidate 1? Core and Builtins Library Security Library IDLE C API Build Documentation Tools/Demos Tests Windows Python 3.6.1 final? Core and Builtins Build Python 3.6.1 release candidate 1? Core and Builtins Library IDLE Windows C API Documentation Tests Build Python 3.6.0 final? Python 3.6.0 release candidate 2? Core and Builtins Tools/Demos Windows Build Python 3.6.0 release candidate 1? Core and Builtins Library C API Documentation Tools/Demos Python 3.6.0 beta 4? Core and Builtins Library Documentation Tests Build Python 3.6.0 beta 3? Core and Builtins Library Windows Build Tests Python 3.6.0 beta 2? Core and Builtins Library Windows C API Build Tests Python 3.6.0 beta 1? Core and Builtins Library IDLE C API Tests Build Tools/Demos Windows Python 3.6.0 alpha 4? Core and Builtins Library IDLE Tests Windows Build Python 3.6.0 alpha 3? Core and Builtins Library Security Library Security Library IDLE C API Build Tools/Demos Documentation Tests Python 3.6.0 alpha 2? Core and Builtins Library Security Library Security Library IDLE Documentation Tests Windows Build Windows C API Tools/Demos Python 3.6.0 alpha 1? Core and Builtins Library Security Library Security Library Security Library IDLE Documentation Tests Build Windows Tools/Demos C API Python 3.5.3 final? Python 3.5.3 release candidate 1? Core and Builtins Library Security Library Security Library IDLE C API Documentation Tests Tools/Demos Windows Build Python 3.5.2 final? Core and Builtins Tests IDLE Python 3.5.2 release candidate 1? Core and Builtins Security Library Security Library Security Library Security Library Security Library IDLE Documentation Tests Build Windows Tools/Demos Windows Python 3.5.1 final? Core and Builtins Windows Python 3.5.1 release candidate 1? Core and Builtins Library IDLE Documentation Tests Build Windows Tools/Demos Python 3.5.0 final? Build Python 3.5.0 release candidate 4? Library Build Python 3.5.0 release candidate 3? Core and Builtins Library Python 3.5.0 release candidate 2? Core and Builtins Library Python 3.5.0 release candidate 1? Core and Builtins Library IDLE Documentation Tests Python 3.5.0 beta 4? Core and Builtins Library Build Python 3.5.0 beta 3? Core and Builtins Library Tests Documentation Build Python 3.5.0 beta 2? Core and Builtins Library Python 3.5.0 beta 1? Core and Builtins Library IDLE Tests Documentation Tools/Demos Python 3.5.0 alpha 4? Core and Builtins Library Build Tests Tools/Demos C API Python 3.5.0 alpha 3? Core and Builtins Library Build Tests Tools/Demos Python 3.5.0 alpha 2? Core and Builtins Library Build C API Windows Python 3.5.0 alpha 1? Core and Builtins Library IDLE Build C API Documentation Tests Tools/Demos Windows The Python Tutorial 1. Whetting Your Appetite 2. Using the Python Interpreter 2.1. Invoking the Interpreter 2.1.1. Argument Passing 2.1.2. Interactive Mode 2.2. The Interpreter and Its Environment 2.2.1. Source Code Encoding 3. An Informal Introduction to Python 3.1. Using Python as a Calculator 3.1.1. Numbers 3.1.2. Strings 3.1.3. Lists 3.2. First Steps Towards Programming 4. More Control Flow Tools 4.1. if Statements 4.2. for Statements 4.3. The range() Function 4.4. break and continue Statements, and else Clauses on Loops 4.5. pass Statements 4.6. Defining Functions 4.7. More on Defining Functions 4.7.1. Default Argument Values 4.7.2. Keyword Arguments 4.7.3. Arbitrary Argument Lists 4.7.4. Unpacking Argument Lists 4.7.5. Lambda Expressions 4.7.6. Documentation Strings 4.7.7. Function Annotations 4.8. Intermezzo: Coding Style 5. Data Structures 5.1. More on Lists 5.1.1. Using Lists as Stacks 5.1.2. Using Lists as Queues 5.1.3. List Comprehensions 5.1.4. Nested List Comprehensions 5.2. The del statement 5.3. Tuples and Sequences 5.4. Sets 5.5. Dictionaries 5.6. Looping Techniques 5.7. More on Conditions 5.8. Comparing Sequences and Other Types 6. Modules 6.1. More on Modules 6.1.1. Executing modules as scripts 6.1.2. The Module Search Path 6.1.3. “Compiled” Python files 6.2. Standard Modules 6.3. The dir() Function 6.4. Packages 6.4.1. Importing * From a Package 6.4.2. Intra-package References 6.4.3. Packages in Multiple Directories 7. Input and Output 7.1. Fancier Output Formatting 7.1.1. Old string formatting 7.2. Reading and Writing Files 7.2.1. Methods of File Objects 7.2.2. Saving structured data with json 8. Errors and Exceptions 8.1. Syntax Errors 8.2. Exceptions 8.3. Handling Exceptions 8.4. Raising Exceptions 8.5. User-defined Exceptions 8.6. Defining Clean-up Actions 8.7. Predefined Clean-up Actions 9. Classes 9.1. A Word About Names and Objects 9.2. Python Scopes and Namespaces 9.2.1. Scopes and Namespaces Example 9.3. A First Look at Classes 9.3.1. Class Definition Syntax 9.3.2. Class Objects 9.3.3. Instance Objects 9.3.4. Method Objects 9.3.5. Class and Instance Variables 9.4. Random Remarks 9.5. Inheritance 9.5.1. Multiple Inheritance 9.6. Private Variables 9.7. Odds and Ends 9.8. Iterators 9.9. Generators 9.10. Generator Expressions 10. Brief Tour of the Standard Library 10.1. Operating System Interface 10.2. File Wildcards 10.3. Command Line Arguments 10.4. Error Output Redirection and Program Termination 10.5. String Pattern Matching 10.6. Mathematics 10.7. Internet Access 10.8. Dates and Times 10.9. Data Compression 10.10. Performance Measurement 10.11. Quality Control 10.12. Batteries Included 11. Brief Tour of the Standard Library — Part II 11.1. Output Formatting 11.2. Templating 11.3. Working with Binary Data Record Layouts 11.4. Multi-threading 11.5. Logging 11.6. Weak References 11.7. Tools for Working with Lists 11.8. Decimal Floating Point Arithmetic 12. Virtual Environments and Packages 12.1. Introduction 12.2. Creating Virtual Environments 12.3. Managing Packages with pip 13. What Now? 14. Interactive Input Editing and History Substitution 14.1. Tab Completion and History Editing 14.2. Alternatives to the Interactive Interpreter 15. Floating Point Arithmetic: Issues and Limitations 15.1. Representation Error 16. Appendix 16.1. Interactive Mode 16.1.1. Error Handling 16.1.2. Executable Python Scripts 16.1.3. The Interactive Startup File 16.1.4. The Customization Modules Python Setup and Usage 1. Command line and environment 1.1. Command line 1.1.1. Interface options 1.1.2. Generic options 1.1.3. Miscellaneous options 1.1.4. Options you shouldn’t use 1.2. Environment variables 1.2.1. Debug-mode variables 2. Using Python on Unix platforms 2.1. Getting and installing the latest version of Python 2.1.1. On Linux 2.1.2. On FreeBSD and OpenBSD 2.1.3. On OpenSolaris 2.2. Building Python 2.3. Python-related paths and files 2.4. Miscellaneous 2.5. Editors and IDEs 3. Using Python on Windows 3.1. Installing Python 3.1.1. Supported Versions 3.1.2. Installation Steps 3.1.3. Removing the MAX_PATH Limitation 3.1.4. Installing Without UI 3.1.5. Installing Without Downloading 3.1.6. Modifying an install 3.1.7. Other Platforms 3.2. Alternative bundles 3.3. Configuring Python 3.3.1. Excursus: Setting environment variables 3.3.2. Finding the Python executable 3.4. Python Launcher for Windows 3.4.1. Getting started 3.4.1.1. From the command-line 3.4.1.2. Virtual environments 3.4.1.3. From a script 3.4.1.4. From file associations 3.4.2. Shebang Lines 3.4.3. Arguments in shebang lines 3.4.4. Customization 3.4.4.1. Customization via INI files 3.4.4.2. Customizing default Python versions 3.4.5. Diagnostics 3.5. Finding modules 3.6. Additional modules 3.6.1. PyWin32 3.6.2. cx_Freeze 3.6.3. WConio 3.7. Compiling Python on Windows 3.8. Embedded Distribution 3.8.1. Python Application 3.8.2. Embedding Python 3.9. Other resources 4. Using Python on a Macintosh 4.1. Getting and Installing MacPython 4.1.1. How to run a Python script 4.1.2. Running scripts with a GUI 4.1.3. Configuration 4.2. The IDE 4.3. Installing Additional Python Packages 4.4. GUI Programming on the Mac 4.5. Distributing Python Applications on the Mac 4.6. Other Resources The Python Language Reference 1. Introduction 1.1. Alternate Implementations 1.2. Notation 2. Lexical analysis 2.1. Line structure 2.1.1. Logical lines 2.1.2. Physical lines 2.1.3. Comments 2.1.4. Encoding declarations 2.1.5. Explicit line joining 2.1.6. Implicit line joining 2.1.7. Blank lines 2.1.8. Indentation 2.1.9. Whitespace between tokens 2.2. Other tokens 2.3. Identifiers and keywords 2.3.1. Keywords 2.3.2. Reserved classes of identifiers 2.4. Literals 2.4.1. String and Bytes literals 2.4.2. String literal concatenation 2.4.3. Formatted string literals 2.4.4. Numeric literals 2.4.5. Integer literals 2.4.6. Floating point literals 2.4.7. Imaginary literals 2.5. Operators 2.6. Delimiters 3. Data model 3.1. Objects, values and types 3.2. The standard type hierarchy 3.3. Special method names 3.3.1. Basic customization 3.3.2. Customizing attribute access 3.3.2.1. Customizing module attribute access 3.3.2.2. Implementing Descriptors 3.3.2.3. Invoking Descriptors 3.3.2.4. __slots__ 3.3.2.4.1. Notes on using __slots__ 3.3.3. Customizing class creation 3.3.3.1. Metaclasses 3.3.3.2. Determining the appropriate metaclass 3.3.3.3. Preparing the class namespace 3.3.3.4. Executing the class body 3.3.3.5. Creating the class object 3.3.3.6. Metaclass example 3.3.4. Customizing instance and subclass checks 3.3.5. Emulating callable objects 3.3.6. Emulating container types 3.3.7. Emulating numeric types 3.3.8. With Statement Context Managers 3.3.9. Special method lookup 3.4. Coroutines 3.4.1. Awaitable Objects 3.4.2. Coroutine Objects 3.4.3. Asynchronous Iterators 3.4.4. Asynchronous Context Managers 4. Execution model 4.1. Structure of a program 4.2. Naming and binding 4.2.1. Binding of names 4.2.2. Resolution of names 4.2.3. Builtins and restricted execution 4.2.4. Interaction with dynamic features 4.3. Exceptions 5. The import system 5.1. importlib 5.2. Packages 5.2.1. Regular packages 5.2.2. Namespace packages 5.3. Searching 5.3.1. The module cache 5.3.2. Finders and loaders 5.3.3. Import hooks 5.3.4. The meta path 5.4. Loading 5.4.1. Loaders 5.4.2. Submodules 5.4.3. Module spec 5.4.4. Import-related module attributes 5.4.5. module.__path__ 5.4.6. Module reprs 5.5. The Path Based Finder 5.5.1. Path entry finders 5.5.2. Path entry finder protocol 5.6. Replacing the standard import system 5.7. Special considerations for __main__ 5.7.1. __main__.__spec__ 5.8. Open issues 5.9. References 6. Expressions 6.1. Arithmetic conversions 6.2. Atoms 6.2.1. Identifiers (Names) 6.2.2. Literals 6.2.3. Parenthesized forms 6.2.4. Displays for lists, sets and dictionaries 6.2.5. List displays 6.2.6. Set displays 6.2.7. Dictionary displays 6.2.8. Generator expressions 6.2.9. Yield expressions 6.2.9.1. Generator-iterator methods 6.2.9.2. Examples 6.2.9.3. Asynchronous generator functions 6.2.9.4. Asynchronous generator-iterator methods 6.3. Primaries 6.3.1. Attribute references 6.3.2. Subscriptions 6.3.3. Slicings 6.3.4. Calls 6.4. Await expression 6.5. The power operator 6.6. Unary arithmetic and bitwise operations 6.7. Binary arithmetic operations 6.8. Shifting operations 6.9. Binary bitwise operations 6.10. Comparisons 6.10.1. Value comparisons 6.10.2. Membership test operations 6.10.3. Identity comparisons 6.11. Boolean operations 6.12. Conditional expressions 6.13. Lambdas 6.14. Expression lists 6.15. Evaluation order 6.16. Operator precedence 7. Simple statements 7.1. Expression statements 7.2. Assignment statements 7.2.1. Augmented assignment statements 7.2.2. Annotated assignment statements 7.3. The assert statement 7.4. The pass statement 7.5. The del statement 7.6. The return statement 7.7. The yield statement 7.8. The raise statement 7.9. The break statement 7.10. The continue statement 7.11. The import statement 7.11.1. Future statements 7.12. The global statement 7.13. The nonlocal statement 8. Compound statements 8.1. The if statement 8.2. The while statement 8.3. The for statement 8.4. The try statement 8.5. The with statement 8.6. Function definitions 8.7. Class definitions 8.8. Coroutines 8.8.1. Coroutine function definition 8.8.2. The async for statement 8.8.3. The async with statement 9. Top-level components 9.1. Complete Python programs 9.2. File input 9.3. Interactive input 9.4. Expression input 10. Full Grammar specification The Python Standard Library 1. Introduction 2. Built-in Functions 3. Built-in Constants 3.1. Constants added by the site module 4. Built-in Types 4.1. Truth Value Testing 4.2. Boolean Operations — and, or, not 4.3. Comparisons 4.4. Numeric Types — int, float, complex 4.4.1. Bitwise Operations on Integer Types 4.4.2. Additional Methods on Integer Types 4.4.3. Additional Methods on Float 4.4.4. Hashing of numeric types 4.5. Iterator Types 4.5.1. Generator Types 4.6. Sequence Types — list, tuple, range 4.6.1. Common Sequence Operations 4.6.2. Immutable Sequence Types 4.6.3. Mutable Sequence Types 4.6.4. Lists 4.6.5. Tuples 4.6.6. Ranges 4.7. Text Sequence Type — str 4.7.1. String Methods 4.7.2. printf-style String Formatting 4.8. Binary Sequence Types — bytes, bytearray, memoryview 4.8.1. Bytes Objects 4.8.2. Bytearray Objects 4.8.3. Bytes and Bytearray Operations 4.8.4. printf-style Bytes Formatting 4.8.5. Memory Views 4.9. Set Types — set, frozenset 4.10. Mapping Types — dict 4.10.1. Dictionary view objects 4.11. Context Manager Types 4.12. Other Built-in Types 4.12.1. Modules 4.12.2. Classes and Class Instances 4.12.3. Functions 4.12.4. Methods 4.12.5. Code Objects 4.12.6. Type Objects 4.12.7. The Null Object 4.12.8. The Ellipsis Object 4.12.9. The NotImplemented Object 4.12.10. Boolean Values 4.12.11. Internal Objects 4.13. Special Attributes 5. Built-in Exceptions 5.1. Base classes 5.2. Concrete exceptions 5.2.1. OS exceptions 5.3. Warnings 5.4. Exception hierarchy 6. Text Processing Services 6.1. string — Common string operations 6.1.1. String constants 6.1.2. Custom String Formatting 6.1.3. Format String Syntax 6.1.3.1. Format Specification Mini-Language 6.1.3.2. Format examples 6.1.4. Template strings 6.1.5. Helper functions 6.2. re — Regular expression operations 6.2.1. Regular Expression Syntax 6.2.2. Module Contents 6.2.3. Regular Expression Objects 6.2.4. Match Objects 6.2.5. Regular Expression Examples 6.2.5.1. Checking for a Pair 6.2.5.2. Simulating scanf() 6.2.5.3. search() vs. match() 6.2.5.4. Making a Phonebook 6.2.5.5. Text Munging 6.2.5.6. Finding all Adverbs 6.2.5.7. Finding all Adverbs and their Positions 6.2.5.8. Raw String Notation 6.2.5.9. Writing a Tokenizer 6.3. difflib — Helpers for computing deltas 6.3.1. SequenceMatcher Objects 6.3.2. SequenceMatcher Examples 6.3.3. Differ Objects 6.3.4. Differ Example 6.3.5. A command-line interface to difflib 6.4. textwrap — Text wrapping and filling 6.5. unicodedata — Unicode Database 6.6. stringprep — Internet String Preparation 6.7. readline — GNU readline interface 6.7.1. Init file 6.7.2. Line buffer 6.7.3. History file 6.7.4. History list 6.7.5. Startup hooks 6.7.6. Completion 6.7.7. Example 6.8. rlcompleter — Completion function for GNU readline 6.8.1. Completer Objects 7. Binary Data Services 7.1. struct — Interpret bytes as packed binary data 7.1.1. Functions and Exceptions 7.1.2. Format Strings 7.1.2.1. Byte Order, Size, and Alignment 7.1.2.2. Format Characters 7.1.2.3. Examples 7.1.3. Classes 7.2. codecs — Codec registry and base classes 7.2.1. Codec Base Classes 7.2.1.1. Error Handlers 7.2.1.2. Stateless Encoding and Decoding 7.2.1.3. Incremental Encoding and Decoding 7.2.1.3.1. IncrementalEncoder Objects 7.2.1.3.2. IncrementalDecoder Objects 7.2.1.4. Stream Encoding and Decoding 7.2.1.4.1. StreamWriter Objects 7.2.1.4.2. StreamReader Objects 7.2.1.4.3. StreamReaderWriter Objects 7.2.1.4.4. StreamRecoder Objects 7.2.2. Encodings and Unicode 7.2.3. Standard Encodings 7.2.4. Python Specific Encodings 7.2.4.1. Text Encodings 7.2.4.2. Binary Transforms 7.2.4.3. Text Transforms 7.2.5. encodings.idna — Internationalized Domain Names in Applications 7.2.6. encodings.mbcs — Windows ANSI codepage 7.2.7. encodings.utf_8_sig — UTF-8 codec with BOM signature 8. Data Types 8.1. datetime — Basic date and time types 8.1.1. Available Types 8.1.2. timedelta Objects 8.1.3. date Objects 8.1.4. datetime Objects 8.1.5. time Objects 8.1.6. tzinfo Objects 8.1.7. timezone Objects 8.1.8. strftime() and strptime() Behavior 8.2. calendar — General calendar-related functions 8.3. collections — Container datatypes 8.3.1. ChainMap objects 8.3.1.1. ChainMap Examples and Recipes 8.3.2. Counter objects 8.3.3. deque objects 8.3.3.1. deque Recipes 8.3.4. defaultdict objects 8.3.4.1. defaultdict Examples 8.3.5. namedtuple() Factory Function for Tuples with Named Fields 8.3.6. OrderedDict objects 8.3.6.1. OrderedDict Examples and Recipes 8.3.7. UserDict objects 8.3.8. UserList objects 8.3.9. UserString objects 8.4. collections.abc — Abstract Base Classes for Containers 8.4.1. Collections Abstract Base Classes 8.5. heapq — Heap queue algorithm 8.5.1. Basic Examples 8.5.2. Priority Queue Implementation Notes 8.5.3. Theory 8.6. bisect — Array bisection algorithm 8.6.1. Searching Sorted Lists 8.6.2. Other Examples 8.7. array — Efficient arrays of numeric values 8.8. weakref — Weak references 8.8.1. Weak Reference Objects 8.8.2. Example 8.8.3. Finalizer Objects 8.8.4. Comparing finalizers with __del__() methods 8.9. types — Dynamic type creation and names for built-in types 8.9.1. Dynamic Type Creation 8.9.2. Standard Interpreter Types 8.9.3. Additional Utility Classes and Functions 8.9.4. Coroutine Utility Functions 8.10. copy — Shallow and deep copy operations 8.11. pprint — Data pretty printer 8.11.1. PrettyPrinter Objects 8.11.2. Example 8.12. reprlib — Alternate repr() implementation 8.12.1. Repr Objects 8.12.2. Subclassing Repr Objects 8.13. enum — Support for enumerations 8.13.1. Module Contents 8.13.2. Creating an Enum 8.13.3. Programmatic access to enumeration members and their attributes 8.13.4. Duplicating enum members and values 8.13.5. Ensuring unique enumeration values 8.13.6. Using automatic values 8.13.7. Iteration 8.13.8. Comparisons 8.13.9. Allowed members and attributes of enumerations 8.13.10. Restricted subclassing of enumerations 8.13.11. Pickling 8.13.12. Functional API 8.13.13. Derived Enumerations 8.13.13.1. IntEnum 8.13.13.2. IntFlag 8.13.13.3. Flag 8.13.13.4. Others 8.13.14. Interesting examples 8.13.14.1. Omitting values 8.13.14.1.1. Using auto 8.13.14.1.2. Using object 8.13.14.1.3. Using a descriptive string 8.13.14.1.4. Using a custom __new__() 8.13.14.2. OrderedEnum 8.13.14.3. DuplicateFreeEnum 8.13.14.4. Planet 8.13.15. How are Enums different? 8.13.15.1. Enum Classes 8.13.15.2. Enum Members (aka instances) 8.13.15.3. Finer Points 8.13.15.3.1. Supported __dunder__ names 8.13.15.3.2. Supported _sunder_ names 8.13.15.3.3. Enum member type 8.13.15.3.4. Boolean value of Enum classes and members 8.13.15.3.5. Enum classes with methods 8.13.15.3.6. Combining members of Flag 9. Numeric and Mathematical Modules 9.1. numbers — Numeric abstract base classes 9.1.1. The numeric tower 9.1.2. Notes for type implementors 9.1.2.1. Adding More Numeric ABCs 9.1.2.2. Implementing the arithmetic operations 9.2. math — Mathematical functions 9.2.1. Number-theoretic and representation functions 9.2.2. Power and logarithmic functions 9.2.3. Trigonometric functions 9.2.4. Angular conversion 9.2.5. Hyperbolic functions 9.2.6. Special functions 9.2.7. Constants 9.3. cmath — Mathematical functions for complex numbers 9.3.1. Conversions to and from polar coordinates 9.3.2. Power and logarithmic functions 9.3.3. Trigonometric functions 9.3.4. Hyperbolic functions 9.3.5. Classification functions 9.3.6. Constants 9.4. decimal — Decimal fixed point and floating point arithmetic 9.4.1. Quick-start Tutorial 9.4.2. Decimal objects 9.4.2.1. Logical operands 9.4.3. Context objects 9.4.4. Constants 9.4.5. Rounding modes 9.4.6. Signals 9.4.7. Floating Point Notes 9.4.7.1. Mitigating round-off error with increased precision 9.4.7.2. Special values 9.4.8. Working with threads 9.4.9. Recipes 9.4.10. Decimal FAQ 9.5. fractions — Rational numbers 9.6. random — Generate pseudo-random numbers 9.6.1. Bookkeeping functions 9.6.2. Functions for integers 9.6.3. Functions for sequences 9.6.4. Real-valued distributions 9.6.5. Alternative Generator 9.6.6. Notes on Reproducibility 9.6.7. Examples and Recipes 9.7. statistics — Mathematical statistics functions 9.7.1. Averages and measures of central location 9.7.2. Measures of spread 9.7.3. Function details 9.7.4. Exceptions 10. Functional Programming Modules 10.1. itertools — Functions creating iterators for efficient looping 10.1.1. Itertool functions 10.1.2. Itertools Recipes 10.2. functools — Higher-order functions and operations on callable objects 10.2.1. partial Objects 10.3. operator — Standard operators as functions 10.3.1. Mapping Operators to Functions 10.3.2. Inplace Operators 11. File and Directory Access 11.1. pathlib — Object-oriented filesystem paths 11.1.1. Basic use 11.1.2. Pure paths 11.1.2.1. General properties 11.1.2.2. Operators 11.1.2.3. Accessing individual parts 11.1.2.4. Methods and properties 11.1.3. Concrete paths 11.1.3.1. Methods 11.2. os.path — Common pathname manipulations 11.3. fileinput — Iterate over lines from multiple input streams 11.4. stat — Interpreting stat() results 11.5. filecmp — File and Directory Comparisons 11.5.1. The dircmp class 11.6. tempfile — Generate temporary files and directories 11.6.1. Examples 11.6.2. Deprecated functions and variables 11.7. glob — Unix style pathname pattern expansion 11.8. fnmatch — Unix filename pattern matching 11.9. linecache — Random access to text lines 11.10. shutil — High-level file operations 11.10.1. Directory and files operations 11.10.1.1. copytree example 11.10.1.2. rmtree example 11.10.2. Archiving operations 11.10.2.1. Archiving example 11.10.3. Querying the size of the output terminal 11.11. macpath — Mac OS 9 path manipulation functions 12. Data Persistence 12.1. pickle — Python object serialization 12.1.1. Relationship to other Python modules 12.1.1.1. Comparison with marshal 12.1.1.2. Comparison with json 12.1.2. Data stream format 12.1.3. Module Interface 12.1.4. What can be pickled and unpickled? 12.1.5. Pickling Class Instances 12.1.5.1. Persistence of External Objects 12.1.5.2. Dispatch Tables 12.1.5.3. Handling Stateful Objects 12.1.6. Restricting Globals 12.1.7. Performance 12.1.8. Examples 12.2. copyreg — Register pickle support functions 12.2.1. Example 12.3. shelve — Python object persistence 12.3.1. Restrictions 12.3.2. Example 12.4. marshal — Internal Python object serialization 12.5. dbm — Interfaces to Unix “databases” 12.5.1. dbm.gnu — GNU’s reinterpretation of dbm 12.5.2. dbm.ndbm — Interface based on ndbm 12.5.3. dbm.dumb — Portable DBM implementation 12.6. sqlite3 — DB-API 2.0 interface for SQLite databases 12.6.1. Module functions and constants 12.6.2. Connection Objects 12.6.3. Cursor Objects 12.6.4. Row Objects 12.6.5. Exceptions 12.6.6. SQLite and Python types 12.6.6.1. Introduction 12.6.6.2. Using adapters to store additional Python types in SQLite databases 12.6.6.2.1. Letting your object adapt itself 12.6.6.2.2. Registering an adapter callable 12.6.6.3. Converting SQLite values to custom Python types 12.6.6.4. Default adapters and converters 12.6.7. Controlling Transactions 12.6.8. Using sqlite3 efficiently 12.6.8.1. Using shortcut methods 12.6.8.2. Accessing columns by name instead of by index 12.6.8.3. Using the connection as a context manager 12.6.9. Common issues 12.6.9.1. Multithreading 13. Data Compression and Archiving 13.1. zlib — Compression compatible with gzip 13.2. gzip — Support for gzip files 13.2.1. Examples of usage 13.3. bz2 — Support for bzip2 compression 13.3.1. (De)compression of files 13.3.2. Incremental (de)compression 13.3.3. One-shot (de)compression 13.4. lzma — Compression using the LZMA algorithm 13.4.1. Reading and writing compressed files 13.4.2. Compressing and decompressing data in memory 13.4.3. Miscellaneous 13.4.4. Specifying custom filter chains 13.4.5. Examples 13.5. zipfile — Work with ZIP archives 13.5.1. ZipFile Objects 13.5.2. PyZipFile Objects 13.5.3. ZipInfo Objects 13.5.4. Command-Line Interface 13.5.4.1. Command-line options 13.6. tarfile — Read and write tar archive files 13.6.1. TarFile Objects 13.6.2. TarInfo Objects 13.6.3. Command-Line Interface 13.6.3.1. Command-line options 13.6.4. Examples 13.6.5. Supported tar formats 13.6.6. Unicode issues 14. File Formats 14.1. csv — CSV File Reading and Writing 14.1.1. Module Contents 14.1.2. Dialects and Formatting Parameters 14.1.3. Reader Objects 14.1.4. Writer Objects 14.1.5. Examples 14.2. configparser — Configuration file parser 14.2.1. Quick Start 14.2.2. Supported Datatypes 14.2.3. Fallback Values 14.2.4. Supported INI File Structure 14.2.5. Interpolation of values 14.2.6. Mapping Protocol Access 14.2.7. Customizing Parser Behaviour 14.2.8. Legacy API Examples 14.2.9. ConfigParser Objects 14.2.10. RawConfigParser Objects 14.2.11. Exceptions 14.3. netrc — netrc file processing 14.3.1. netrc Objects 14.4. xdrlib — Encode and decode XDR data 14.4.1. Packer Objects 14.4.2. Unpacker Objects 14.4.3. Exceptions 14.5. plistlib — Generate and parse Mac OS X .plist files 14.5.1. Examples 15. Cryptographic Services 15.1. hashlib — Secure hashes and message digests 15.1.1. Hash algorithms 15.1.2. SHAKE variable length digests 15.1.3. Key derivation 15.1.4. BLAKE2 15.1.4.1. Creating hash objects 15.1.4.2. Constants 15.1.4.3. Examples 15.1.4.3.1. Simple hashing 15.1.4.3.2. Using different digest sizes 15.1.4.3.3. Keyed hashing 15.1.4.3.4. Randomized hashing 15.1.4.3.5. Personalization 15.1.4.3.6. Tree mode 15.1.4.4. Credits 15.2. hmac — Keyed-Hashing for Message Authentication 15.3. secrets — Generate secure random numbers for managing secrets 15.3.1. Random numbers 15.3.2. Generating tokens 15.3.2.1. How many bytes should tokens use? 15.3.3. Other functions 15.3.4. Recipes and best practices 16. Generic Operating System Services 16.1. os — Miscellaneous operating system interfaces 16.1.1. File Names, Command Line Arguments, and Environment Variables 16.1.2. Process Parameters 16.1.3. File Object Creation 16.1.4. File Descriptor Operations 16.1.4.1. Querying the size of a terminal 16.1.4.2. Inheritance of File Descriptors 16.1.5. Files and Directories 16.1.5.1. Linux extended attributes 16.1.6. Process Management 16.1.7. Interface to the scheduler 16.1.8. Miscellaneous System Information 16.1.9. Random numbers 16.2. io — Core tools for working with streams 16.2.1. Overview 16.2.1.1. Text I/O 16.2.1.2. Binary I/O 16.2.1.3. Raw I/O 16.2.2. High-level Module Interface 16.2.2.1. In-memory streams 16.2.3. Class hierarchy 16.2.3.1. I/O Base Classes 16.2.3.2. Raw File I/O 16.2.3.3. Buffered Streams 16.2.3.4. Text I/O 16.2.4. Performance 16.2.4.1. Binary I/O 16.2.4.2. Text I/O 16.2.4.3. Multi-threading 16.2.4.4. Reentrancy 16.3. time — Time access and conversions 16.3.1. Functions 16.3.2. Clock ID Constants 16.3.3. Timezone Constants 16.4. argparse — Parser for command-line options, arguments and sub-commands 16.4.1. Example 16.4.1.1. Creating a parser 16.4.1.2. Adding arguments 16.4.1.3. Parsing arguments 16.4.2. ArgumentParser objects 16.4.2.1. prog 16.4.2.2. usage 16.4.2.3. description 16.4.2.4. epilog 16.4.2.5. parents 16.4.2.6. formatter_class 16.4.2.7. prefix_chars 16.4.2.8. fromfile_prefix_chars 16.4.2.9. argument_default 16.4.2.10. allow_abbrev 16.4.2.11. conflict_handler 16.4.2.12. add_help 16.4.3. The add_argument() method 16.4.3.1. name or flags 16.4.3.2. action 16.4.3.3. nargs 16.4.3.4. const 16.4.3.5. default 16.4.3.6. type 16.4.3.7. choices 16.4.3.8. required 16.4.3.9. help 16.4.3.10. metavar 16.4.3.11. dest 16.4.3.12. Action classes 16.4.4. The parse_args() method 16.4.4.1. Option value syntax 16.4.4.2. Invalid arguments 16.4.4.3. Arguments containing - 16.4.4.4. Argument abbreviations (prefix matching) 16.4.4.5. Beyond sys.argv 16.4.4.6. The Namespace object 16.4.5. Other utilities 16.4.5.1. Sub-commands 16.4.5.2. FileType objects 16.4.5.3. Argument groups 16.4.5.4. Mutual exclusion 16.4.5.5. Parser defaults 16.4.5.6. Printing help 16.4.5.7. Partial parsing 16.4.5.8. Customizing file parsing 16.4.5.9. Exiting methods 16.4.6. Upgrading optparse code 16.5. getopt — C-style parser for command line options 16.6. logging — Logging facility for Python 16.6.1. Logger Objects 16.6.2. Logging Levels 16.6.3. Handler Objects 16.6.4. Formatter Objects 16.6.5. Filter Objects 16.6.6. LogRecord Objects 16.6.7. LogRecord attributes 16.6.8. LoggerAdapter Objects 16.6.9. Thread Safety 16.6.10. Module-Level Functions 16.6.11. Module-Level Attributes 16.6.12. Integration with the warnings module 16.7. logging.config — Logging configuration 16.7.1. Configuration functions 16.7.2. Configuration dictionary schema 16.7.2.1. Dictionary Schema Details 16.7.2.2. Incremental Configuration 16.7.2.3. Object connections 16.7.2.4. User-defined objects 16.7.2.5. Access to external objects 16.7.2.6. Access to internal objects 16.7.2.7. Import resolution and custom importers 16.7.3. Configuration file format 16.8. logging.handlers — Logging handlers 16.8.1. StreamHandler 16.8.2. FileHandler 16.8.3. NullHandler 16.8.4. WatchedFileHandler 16.8.5. BaseRotatingHandler 16.8.6. RotatingFileHandler 16.8.7. TimedRotatingFileHandler 16.8.8. SocketHandler 16.8.9. DatagramHandler 16.8.10. SysLogHandler 16.8.11. NTEventLogHandler 16.8.12. SMTPHandler 16.8.13. MemoryHandler 16.8.14. HTTPHandler 16.8.15. QueueHandler 16.8.16. QueueListener 16.9. getpass — Portable password input 16.10. curses — Terminal handling for character-cell displays 16.10.1. Functions 16.10.2. Window Objects 16.10.3. Constants 16.11. curses.textpad — Text input widget for curses programs 16.11.1. Textbox objects 16.12. curses.ascii — Utilities for ASCII characters 16.13. curses.panel — A panel stack extension for curses 16.13.1. Functions 16.13.2. Panel Objects 16.14. platform — Access to underlying platform’s identifying data 16.14.1. Cross Platform 16.14.2. Java Platform 16.14.3. Windows Platform 16.14.3.1. Win95/98 specific 16.14.4. Mac OS Platform 16.14.5. Unix Platforms 16.15. errno — Standard errno system symbols 16.16. ctypes — A foreign function library for Python 16.16.1. ctypes tutorial 16.16.1.1. Loading dynamic link libraries 16.16.1.2. Accessing functions from loaded dlls 16.16.1.3. Calling functions 16.16.1.4. Fundamental data types 16.16.1.5. Calling functions, continued 16.16.1.6. Calling functions with your own custom data types 16.16.1.7. Specifying the required argument types (function prototypes) 16.16.1.8. Return types 16.16.1.9. Passing pointers (or: passing parameters by reference) 16.16.1.10. Structures and unions 16.16.1.11. Structure/union alignment and byte order 16.16.1.12. Bit fields in structures and unions 16.16.1.13. Arrays 16.16.1.14. Pointers 16.16.1.15. Type conversions 16.16.1.16. Incomplete Types 16.16.1.17. Callback functions 16.16.1.18. Accessing values exported from dlls 16.16.1.19. Surprises 16.16.1.20. Variable-sized data types 16.16.2. ctypes reference 16.16.2.1. Finding shared libraries 16.16.2.2. Loading shared libraries 16.16.2.3. Foreign functions 16.16.2.4. Function prototypes 16.16.2.5. Utility functions 16.16.2.6. Data types 16.16.2.7. Fundamental data types 16.16.2.8. Structured data types 16.16.2.9. Arrays and pointers 17. Concurrent Execution 17.1. threading — Thread-based parallelism 17.1.1. Thread-Local Data 17.1.2. Thread Objects 17.1.3. Lock Objects 17.1.4. RLock Objects 17.1.5. Condition Objects 17.1.6. Semaphore Objects 17.1.6.1. Semaphore Example 17.1.7. Event Objects 17.1.8. Timer Objects 17.1.9. Barrier Objects 17.1.10. Using locks, conditions, and semaphores in the with statement 17.2. multiprocessing — Process-based parallelism 17.2.1. Introduction 17.2.1.1. The Process class 17.2.1.2. Contexts and start methods 17.2.1.3. Exchanging objects between processes 17.2.1.4. Synchronization between processes 17.2.1.5. Sharing state between processes 17.2.1.6. Using a pool of workers 17.2.2. Reference 17.2.2.1. Process and exceptions 17.2.2.2. Pipes and Queues 17.2.2.3. Miscellaneous 17.2.2.4. Connection Objects 17.2.2.5. Synchronization primitives 17.2.2.6. Shared ctypes Objects 17.2.2.6.1. The multiprocessing.sharedctypes module 17.2.2.7. Managers 17.2.2.7.1. Customized managers 17.2.2.7.2. Using a remote manager 17.2.2.8. Proxy Objects 17.2.2.8.1. Cleanup 17.2.2.9. Process Pools 17.2.2.10. Listeners and Clients 17.2.2.10.1. Address Formats 17.2.2.11. Authentication keys 17.2.2.12. Logging 17.2.2.13. The multiprocessing.dummy module 17.2.3. Programming guidelines 17.2.3.1. All start methods 17.2.3.2. The spawn and forkserver start methods 17.2.4. Examples 17.3. The concurrent package 17.4. concurrent.futures — Launching parallel tasks 17.4.1. Executor Objects 17.4.2. ThreadPoolExecutor 17.4.2.1. ThreadPoolExecutor Example 17.4.3. ProcessPoolExecutor 17.4.3.1. ProcessPoolExecutor Example 17.4.4. Future Objects 17.4.5. Module Functions 17.4.6. Exception classes 17.5. subprocess — Subprocess management 17.5.1. Using the subprocess Module 17.5.1.1. Frequently Used Arguments 17.5.1.2. Popen Constructor 17.5.1.3. Exceptions 17.5.2. Security Considerations 17.5.3. Popen Objects 17.5.4. Windows Popen Helpers 17.5.4.1. Constants 17.5.5. Older high-level API 17.5.6. Replacing Older Functions with the subprocess Module 17.5.6.1. Replacing /bin/sh shell backquote 17.5.6.2. Replacing shell pipeline 17.5.6.3. Replacing os.system() 17.5.6.4. Replacing the os.spawn family 17.5.6.5. Replacing os.popen(), os.popen2(), os.popen3() 17.5.6.6. Replacing functions from the popen2 module 17.5.7. Legacy Shell Invocation Functions 17.5.8. Notes 17.5.8.1. Converting an argument sequence to a string on Windows 17.6. sched — Event scheduler 17.6.1. Scheduler Objects 17.7. queue — A synchronized queue class 17.7.1. Queue Objects 17.8. dummy_threading — Drop-in replacement for the threading module 17.9. _thread — Low-level threading API 17.10. _dummy_thread — Drop-in replacement for the _thread module 18. Interprocess Communication and Networking 18.1. socket — Low-level networking interface 18.1.1. Socket families 18.1.2. Module contents 18.1.2.1. Exceptions 18.1.2.2. Constants 18.1.2.3. Functions 18.1.2.3.1. Creating sockets 18.1.2.3.2. Other functions 18.1.3. Socket Objects 18.1.4. Notes on socket timeouts 18.1.4.1. Timeouts and the connect method 18.1.4.2. Timeouts and the accept method 18.1.5. Example 18.2. ssl — TLS/SSL wrapper for socket objects 18.2.1. Functions, Constants, and Exceptions 18.2.1.1. Socket creation 18.2.1.2. Context creation 18.2.1.3. Random generation 18.2.1.4. Certificate handling 18.2.1.5. Constants 18.2.2. SSL Sockets 18.2.3. SSL Contexts 18.2.4. Certificates 18.2.4.1. Certificate chains 18.2.4.2. CA certificates 18.2.4.3. Combined key and certificate 18.2.4.4. Self-signed certificates 18.2.5. Examples 18.2.5.1. Testing for SSL support 18.2.5.2. Client-side operation 18.2.5.3. Server-side operation 18.2.6. Notes on non-blocking sockets 18.2.7. Memory BIO Support 18.2.8. SSL session 18.2.9. Security considerations 18.2.9.1. Best defaults 18.2.9.2. Manual settings 18.2.9.2.1. Verifying certificates 18.2.9.2.2. Protocol versions 18.2.9.2.3. Cipher selection 18.2.9.3. Multi-processing 18.2.10. LibreSSL support 18.3. select — Waiting for I/O completion 18.3.1. /dev/poll Polling Objects 18.3.2. Edge and Level Trigger Polling (epoll) Objects 18.3.3. Polling Objects 18.3.4. Kqueue Objects 18.3.5. Kevent Objects 18.4. selectors — High-level I/O multiplexing 18.4.1. Introduction 18.4.2. Classes 18.4.3. Examples 18.5. asyncio — Asynchronous I/O, event loop, coroutines and tasks 18.5.1. Base Event Loop 18.5.1.1. Run an event loop 18.5.1.2. Calls 18.5.1.3. Delayed calls 18.5.1.4. Futures 18.5.1.5. Tasks 18.5.1.6. Creating connections 18.5.1.7. Creating listening connections 18.5.1.8. Watch file descriptors 18.5.1.9. Low-level socket operations 18.5.1.10. Resolve host name 18.5.1.11. Connect pipes 18.5.1.12. UNIX signals 18.5.1.13. Executor 18.5.1.14. Error Handling API 18.5.1.15. Debug mode 18.5.1.16. Server 18.5.1.17. Handle 18.5.1.18. Event loop examples 18.5.1.18.1. Hello World with call_soon() 18.5.1.18.2. Display the current date with call_later() 18.5.1.18.3. Watch a file descriptor for read events 18.5.1.18.4. Set signal handlers for SIGINT and SIGTERM 18.5.2. Event loops 18.5.2.1. Event loop functions 18.5.2.2. Available event loops 18.5.2.3. Platform support 18.5.2.3.1. Windows 18.5.2.3.2. Mac OS X 18.5.2.4. Event loop policies and the default policy 18.5.2.5. Event loop policy interface 18.5.2.6. Access to the global loop policy 18.5.2.7. Customizing the event loop policy 18.5.3. Tasks and coroutines 18.5.3.1. Coroutines 18.5.3.1.1. Example: Hello World coroutine 18.5.3.1.2. Example: Coroutine displaying the current date 18.5.3.1.3. Example: Chain coroutines 18.5.3.2. InvalidStateError 18.5.3.3. TimeoutError 18.5.3.4. Future 18.5.3.4.1. Example: Future with run_until_complete() 18.5.3.4.2. Example: Future with run_forever() 18.5.3.5. Task 18.5.3.5.1. Example: Parallel execution of tasks 18.5.3.6. Task functions 18.5.4. Transports and protocols (callback based API) 18.5.4.1. Transports 18.5.4.1.1. BaseTransport 18.5.4.1.2. ReadTransport 18.5.4.1.3. WriteTransport 18.5.4.1.4. DatagramTransport 18.5.4.1.5. BaseSubprocessTransport 18.5.4.2. Protocols 18.5.4.2.1. Protocol classes 18.5.4.2.2. Connection callbacks 18.5.4.2.3. Streaming protocols 18.5.4.2.4. Datagram protocols 18.5.4.2.5. Flow control callbacks 18.5.4.2.6. Coroutines and protocols 18.5.4.3. Protocol examples 18.5.4.3.1. TCP echo client protocol 18.5.4.3.2. TCP echo server protocol 18.5.4.3.3. UDP echo client protocol 18.5.4.3.4. UDP echo server protocol 18.5.4.3.5. Register an open socket to wait for data using a protocol 18.5.5. Streams (coroutine based API) 18.5.5.1. Stream functions 18.5.5.2. StreamReader 18.5.5.3. StreamWriter 18.5.5.4. StreamReaderProtocol 18.5.5.5. IncompleteReadError 18.5.5.6. LimitOverrunError 18.5.5.7. Stream examples 18.5.5.7.1. TCP echo client using streams 18.5.5.7.2. TCP echo server using streams 18.5.5.7.3. Get HTTP headers 18.5.5.7.4. Register an open socket to wait for data using streams 18.5.6. Subprocess 18.5.6.1. Windows event loop 18.5.6.2. Create a subprocess: high-level API using Process 18.5.6.3. Create a subprocess: low-level API using subprocess.Popen 18.5.6.4. Constants 18.5.6.5. Process 18.5.6.6. Subprocess and threads 18.5.6.7. Subprocess examples 18.5.6.7.1. Subprocess using transport and protocol 18.5.6.7.2. Subprocess using streams 18.5.7. Synchronization primitives 18.5.7.1. Locks 18.5.7.1.1. Lock 18.5.7.1.2. Event 18.5.7.1.3. Condition 18.5.7.2. Semaphores 18.5.7.2.1. Semaphore 18.5.7.2.2. BoundedSemaphore 18.5.8. Queues 18.5.8.1. Queue 18.5.8.2. PriorityQueue 18.5.8.3. LifoQueue 18.5.8.3.1. Exceptions 18.5.9. Develop with asyncio 18.5.9.1. Debug mode of asyncio 18.5.9.2. Cancellation 18.5.9.3. Concurrency and multithreading 18.5.9.4. Handle blocking functions correctly 18.5.9.5. Logging 18.5.9.6. Detect coroutine objects never scheduled 18.5.9.7. Detect exceptions never consumed 18.5.9.8. Chain coroutines correctly 18.5.9.9. Pending task destroyed 18.5.9.10. Close transports and event loops 18.6. asyncore — Asynchronous socket handler 18.6.1. asyncore Example basic HTTP client 18.6.2. asyncore Example basic echo server 18.7. asynchat — Asynchronous socket command/response handler 18.7.1. asynchat Example 18.8. signal — Set handlers for asynchronous events 18.8.1. General rules 18.8.1.1. Execution of Python signal handlers 18.8.1.2. Signals and threads 18.8.2. Module contents 18.8.3. Example 18.9. mmap — Memory-mapped file support 19. Internet Data Handling 19.1. email — An email and MIME handling package 19.1.1. email.message: Representing an email message 19.1.2. email.parser: Parsing email messages 19.1.2.1. FeedParser API 19.1.2.2. Parser API 19.1.2.3. Additional notes 19.1.3. email.generator: Generating MIME documents 19.1.4. email.policy: Policy Objects 19.1.5. email.errors: Exception and Defect classes 19.1.6. email.headerregistry: Custom Header Objects 19.1.7. email.contentmanager: Managing MIME Content 19.1.7.1. Content Manager Instances 19.1.8. email: Examples 19.1.9. email.message.Message: Representing an email message using the compat32 API 19.1.10. email.mime: Creating email and MIME objects from scratch 19.1.11. email.header: Internationalized headers 19.1.12. email.charset: Representing character sets 19.1.13. email.encoders: Encoders 19.1.14. email.utils: Miscellaneous utilities 19.1.15. email.iterators: Iterators 19.2. json — JSON encoder and decoder 19.2.1. Basic Usage 19.2.2. Encoders and Decoders 19.2.3. Exceptions 19.2.4. Standard Compliance and Interoperability 19.2.4.1. Character Encodings 19.2.4.2. Infinite and NaN Number Values 19.2.4.3. Repeated Names Within an Object 19.2.4.4. Top-level Non-Object, Non-Array Values 19.2.4.5. Implementation Limitations 19.2.5. Command Line Interface 19.2.5.1. Command line options 19.3. mailcap — Mailcap file handling 19.4. mailbox — Manipulate mailboxes in various formats 19.4.1. Mailbox objects 19.4.1.1. Maildir 19.4.1.2. mbox 19.4.1.3. MH 19.4.1.4. Babyl 19.4.1.5. MMDF 19.4.2. Message objects 19.4.2.1. MaildirMessage 19.4.2.2. mboxMessage 19.4.2.3. MHMessage 19.4.2.4. BabylMessage 19.4.2.5. MMDFMessage 19.4.3. Exceptions 19.4.4. Examples 19.5. mimetypes — Map filenames to MIME types 19.5.1. MimeTypes Objects 19.6. base64 — Base16, Base32, Base64, Base85 Data Encodings 19.7. binhex — Encode and decode binhex4 files 19.7.1. Notes 19.8. binascii — Convert between binary and ASCII 19.9. quopri — Encode and decode MIME quoted-printable data 19.10. uu — Encode and decode uuencode files 20. Structured Markup Processing Tools 20.1. html — HyperText Markup Language support 20.2. html.parser — Simple HTML and XHTML parser 20.2.1. Example HTML Parser Application 20.2.2. HTMLParser Methods 20.2.3. Examples 20.3. html.entities — Definitions of HTML general entities 20.4. XML Processing Modules 20.4.1. XML vulnerabilities 20.4.2. The defusedxml and defusedexpat Packages 20.5. xml.etree.ElementTree — The ElementTree XML API 20.5.1. Tutorial 20.5.1.1. XML tree and elements 20.5.1.2. Parsing XML 20.5.1.3. Pull API for non-blocking parsing 20.5.1.4. Finding interesting elements 20.5.1.5. Modifying an XML File 20.5.1.6. Building XML documents 20.5.1.7. Parsing XML with Namespaces 20.5.1.8. Additional resources 20.5.2. XPath support 20.5.2.1. Example 20.5.2.2. Supported XPath syntax 20.5.3. Reference 20.5.3.1. Functions 20.5.3.2. Element Objects 20.5.3.3. ElementTree Objects 20.5.3.4. QName Objects 20.5.3.5. TreeBuilder Objects 20.5.3.6. XMLParser Objects 20.5.3.7. XMLPullParser Objects 20.5.3.8. Exceptions 20.6. xml.dom — The Document Object Model API 20.6.1. Module Contents 20.6.2. Objects in the DOM 20.6.2.1. DOMImplementation Objects 20.6.2.2. Node Objects 20.6.2.3. NodeList Objects 20.6.2.4. DocumentType Objects 20.6.2.5. Document Objects 20.6.2.6. Element Objects 20.6.2.7. Attr Objects 20.6.2.8. NamedNodeMap Objects 20.6.2.9. Comment Objects 20.6.2.10. Text and CDATASection Objects 20.6.2.11. ProcessingInstruction Objects 20.6.2.12. Exceptions 20.6.3. Conformance 20.6.3.1. Type Mapping 20.6.3.2. Accessor Methods 20.7. xml.dom.minidom — Minimal DOM implementation 20.7.1. DOM Objects 20.7.2. DOM Example 20.7.3. minidom and the DOM standard 20.8. xml.dom.pulldom — Support for building partial DOM trees 20.8.1. DOMEventStream Objects 20.9. xml.sax — Support for SAX2 parsers 20.9.1. SAXException Objects 20.10. xml.sax.handler — Base classes for SAX handlers 20.10.1. ContentHandler Objects 20.10.2. DTDHandler Objects 20.10.3. EntityResolver Objects 20.10.4. ErrorHandler Objects 20.11. xml.sax.saxutils — SAX Utilities 20.12. xml.sax.xmlreader — Interface for XML parsers 20.12.1. XMLReader Objects 20.12.2. IncrementalParser Objects 20.12.3. Locator Objects 20.12.4. InputSource Objects 20.12.5. The Attributes Interface 20.12.6. The AttributesNS Interface 20.13. xml.parsers.expat — Fast XML parsing using Expat 20.13.1. XMLParser Objects 20.13.2. ExpatError Exceptions 20.13.3. Example 20.13.4. Content Model Descriptions 20.13.5. Expat error constants 21. Internet Protocols and Support 21.1. webbrowser — Convenient Web-browser controller 21.1.1. Browser Controller Objects 21.2. cgi — Common Gateway Interface support 21.2.1. Introduction 21.2.2. Using the cgi module 21.2.3. Higher Level Interface 21.2.4. Functions 21.2.5. Caring about security 21.2.6. Installing your CGI script on a Unix system 21.2.7. Testing your CGI script 21.2.8. Debugging CGI scripts 21.2.9. Common problems and solutions 21.3. cgitb — Traceback manager for CGI scripts 21.4. wsgiref — WSGI Utilities and Reference Implementation 21.4.1. wsgiref.util – WSGI environment utilities 21.4.2. wsgiref.headers – WSGI response header tools 21.4.3. wsgiref.simple_server – a simple WSGI HTTP server 21.4.4. wsgiref.validate — WSGI conformance checker 21.4.5. wsgiref.handlers – server/gateway base classes 21.4.6. Examples 21.5. urllib — URL handling modules 21.6. urllib.request — Extensible library for opening URLs 21.6.1. Request Objects 21.6.2. OpenerDirector Objects 21.6.3. BaseHandler Objects 21.6.4. HTTPRedirectHandler Objects 21.6.5. HTTPCookieProcessor Objects 21.6.6. ProxyHandler Objects 21.6.7. HTTPPasswordMgr Objects 21.6.8. HTTPPasswordMgrWithPriorAuth Objects 21.6.9. AbstractBasicAuthHandler Objects 21.6.10. HTTPBasicAuthHandler Objects 21.6.11. ProxyBasicAuthHandler Objects 21.6.12. AbstractDigestAuthHandler Objects 21.6.13. HTTPDigestAuthHandler Objects 21.6.14. ProxyDigestAuthHandler Objects 21.6.15. HTTPHandler Objects 21.6.16. HTTPSHandler Objects 21.6.17. FileHandler Objects 21.6.18. DataHandler Objects 21.6.19. FTPHandler Objects 21.6.20. CacheFTPHandler Objects 21.6.21. UnknownHandler Objects 21.6.22. HTTPErrorProcessor Objects 21.6.23. Examples 21.6.24. Legacy interface 21.6.25. urllib.request Restrictions 21.7. urllib.response — Response classes used by urllib 21.8. urllib.parse — Parse URLs into components 21.8.1. URL Parsing 21.8.2. Parsing ASCII Encoded Bytes 21.8.3. Structured Parse Results 21.8.4. URL Quoting 21.9. urllib.error — Exception classes raised by urllib.request 21.10. urllib.robotparser — Parser for robots.txt 21.11. http — HTTP modules 21.11.1. HTTP status codes 21.12. http.client — HTTP protocol client 21.12.1. HTTPConnection Objects 21.12.2. HTTPResponse Objects 21.12.3. Examples 21.12.4. HTTPMessage Objects 21.13. ftplib — FTP protocol client 21.13.1. FTP Objects 21.13.2. FTP_TLS Objects 21.14. poplib — POP3 protocol client 21.14.1. POP3 Objects 21.14.2. POP3 Example 21.15. imaplib — IMAP4 protocol client 21.15.1. IMAP4 Objects 21.15.2. IMAP4 Example 21.16. nntplib — NNTP protocol client 21.16.1. NNTP Objects 21.16.1.1. Attributes 21.16.1.2. Methods 21.16.2. Utility functions 21.17. smtplib — SMTP protocol client 21.17.1. SMTP Objects 21.17.2. SMTP Example 21.18. smtpd — SMTP Server 21.18.1. SMTPServer Objects 21.18.2. DebuggingServer Objects 21.18.3. PureProxy Objects 21.18.4. MailmanProxy Objects 21.18.5. SMTPChannel Objects 21.19. telnetlib — Telnet client 21.19.1. Telnet Objects 21.19.2. Telnet Example 21.20. uuid — UUID objects according to RFC 4122 21.20.1. Example 21.21. socketserver — A framework for network servers 21.21.1. Server Creation Notes 21.21.2. Server Objects 21.21.3. Request Handler Objects 21.21.4. Examples 21.21.4.1. socketserver.TCPServer Example 21.21.4.2. socketserver.UDPServer Example 21.21.4.3. Asynchronous Mixins 21.22. http.server — HTTP servers 21.23. http.cookies — HTTP state management 21.23.1. Cookie Objects 21.23.2. Morsel Objects 21.23.3. Example 21.24. http.cookiejar — Cookie handling for HTTP clients 21.24.1. CookieJar and FileCookieJar Objects 21.24.2. FileCookieJar subclasses and co-operation with web browsers 21.24.3. CookiePolicy Objects 21.24.4. DefaultCookiePolicy Objects 21.24.5. Cookie Objec

Lerner -- Python Workout. 50 Essential Exercises -- 2020.pdf

Lerner -- Python Workout. 50 Essential Exercises -- 2020.pdf

Lerner -- Python Workout. 50 Essential Exercises -- 2020

python编程必备英语(全)

python编程必备英语(全)

python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)python编程必备英语(全)

【Python编程教育】计算机二级考试专项训练题库:选择填空编程全题型备考指南

【Python编程教育】计算机二级考试专项训练题库:选择填空编程全题型备考指南

内容概要:本文档是一份针对全国计算机等级考试二级Python科目的专项题库,涵盖选择题、填空题和编程题三大模块,内容涉及Python基础语法、数据类型与运算、流程控制、函数与模块、文件操作等核心知识点。每道题目均配有详细解析,帮助考生理解考点并掌握解题思路,同时提供编程题参考代码与实现逻辑说明,强化实际编程能力训练。; 适合人群:准备参加计算机二级Python考试的在校学生或初学者,具备基本Python语法基础的学习者;; 使用场景及目标:①系统复习Python核心语法知识,查漏补缺;②熟悉考试常见题型与出题方式,提升应试能力;③通过练习编程题增强代码实践能力,掌握典型算法与程序结构;; 阅读建议:建议按照章节顺序逐步练习,结合解析深入理解错误原因,对编程题应动手调试代码以加深印象,配合真题模拟全面提升通过率。

byte_of_pythom

byte_of_pythom

python入门手册,pdf格式

易语言源码程序之间通信模拟

易语言源码程序之间通信模拟

易语言源码程序之间通信模拟

计及切负荷和直流潮流(DC-OPF)风-火-储经济调度模型研究(Matlab代码实现)

计及切负荷和直流潮流(DC-OPF)风-火-储经济调度模型研究(Matlab代码实现)

计及切负荷和直流潮流(DC-OPF)风-火-储经济调度模型研究(Matlab代码实现)

无人机四旋翼飞行器控制、路径规划和轨迹优化(Matlab实现)

无人机四旋翼飞行器控制、路径规划和轨迹优化(Matlab实现)

【无人机】四旋翼飞行器控制、路径规划和轨迹优化(Matlab实现)

机械毕业设计-大倾角带式运输机的设计.rar

机械毕业设计-大倾角带式运输机的设计.rar

机械毕业设计-大倾角带式运输机的设计.rar

MySQL8.0中文手册

MySQL8.0中文手册

代码下载地址: https://pan.quark.cn/s/abf4dc58da8e Mysql8.0ReferenceManual_Translation 这里是MySQL8.0官方文档的中文翻译,欢迎有兴趣的同学一起参与,共同为开源世界添砖加瓦! 缘起 一直认为学习MySQL最好的方法就是通读官方文档,但却一直苦于蹩脚的英文和没有好的中文翻译,导致即使用了很多年的MySQL,却发现对MySQL的理解还是停留在最浅显的层面,和新手无异,这何尝不是一种悲哀。 痛定思痛,决定还是要忍着差劲的英文读一读官方文档,并且选择当前(2019-07-16)最新的MySQL8.0入手,同时再把它翻译成中文,一方面加深自己的印象,一方面也是方便后来者学习,也算是为开源世界贡献点力量。 关于本项目 由于完整翻译MySQL文档也是个工作量相当浩大的工程,所以前期我不会完全按照文档的顺序从前向后翻译,而是针对性的选择自己认为比较重要的先翻译,一方面也是自己学习的需要,另一方面也是怕从前到后这样翻译太过无聊,自己无法坚持下来,可能等到将来某一天完成的七七八八的时候,再查漏补缺,形成完整的翻译也就是水到渠成的事情了。 开始阅读

机械毕业设计-多功能蔬菜切片机设计.rar

机械毕业设计-多功能蔬菜切片机设计.rar

机械毕业设计-多功能蔬菜切片机设计.rar

储能参与现货电能量-调频辅助服务市场的双层交易决策研究(Matlab代码实现)

储能参与现货电能量-调频辅助服务市场的双层交易决策研究(Matlab代码实现)

储能参与现货电能量-调频辅助服务市场的双层交易决策研究(Matlab代码实现)

分布式四轮驱动整车建模和控制Simulink仿真模型

分布式四轮驱动整车建模和控制Simulink仿真模型

分布式四轮驱动整车建模和控制Simulink仿真模型

【SCI一区论文复现】自适应强化学习机械臂控制研究(Maltab代码实现)

【SCI一区论文复现】自适应强化学习机械臂控制研究(Maltab代码实现)

【SCI一区论文复现】自适应强化学习机械臂控制研究(Maltab代码实现)

帧率计算方法-下载即用.zip

帧率计算方法-下载即用.zip

源码链接: https://pan.quark.cn/s/6dd1a6ce6e18 帧率计算方法在手机开发领域中占据着核心地位,因为滑动性能问题的评估标准以及计算方法的精确度会直接关联到应用程序的整体用户体验。在接下来的内容中,我们将深入阐释两种帧率计算方法:方法一(测试方法一)与方法二(测试方法二)。 方法一:基于帧数统计的计算方式该方法主要依赖于对画面中的帧数进行计数来估算帧率。具体而言,一个清晰的帧指的是所选画面中不存在拖影的情况,可计为一帧;而拖影直接从主图像的左侧过渡到右侧,且此两帧之间没有无拖影的帧,同样算作一帧。帧率的计算公式为:统计到的画面帧数除以所选总帧数,再乘以录制过程中使用的帧数。 方法二:采用adb命令的测量途径该方法主要利用adb命令来评估帧率。首先,需要开启Developer options中的Monitoring功能,并选择Profile GPU rending,将其设置为In adb shell dumpsys gfxinfo。接着,启动adb debugging,并将手机与电脑连接,确保手机端adb工具已正确连接。随后,在电脑的命令行界面输入命令adb shell dumpsys gfxinfo com.android.contacts > fps.txt(注意此处仅输入命令,暂不按下回车键)。清理后台运行的应用程序后,启动需要测试帧率的应用,并保持进行滑动操作2至3秒(时间可稍长,但不宜过短)。在命令行按下回车键执行上述adb命令,电脑端将生成fps.txt文件。帧率的计算步骤为:打开fps.txt文件,参考附件中的格式。将文件中从第45行至第165行的数据(即从Draw Prepare Process Execu...

基于图像处理技术的森林火灾检测方法与Matlab实现代码

基于图像处理技术的森林火灾检测方法与Matlab实现代码

本代码适用于Matlab 2014、2019a及2024a版本,并附带案例数据,可直接运行。其显著特点在于采用参数化编程模式,用户可便捷调整参数,且代码结构清晰、注释详尽。本程序尤其适合计算机、电子信息工程、数学等专业的学生,用于完成课程设计、期末作业或毕业设计等任务。 森林火灾的预警与防控是当前环境保护与林业管理领域的关键议题。随着图像处理技术的发展,其在火灾早期探测中的应用日益重要。本文旨在系统阐述基于图像处理的森林火灾检测方法,并结合Matlab代码进行深度解析。 该技术的核心流程如下:首先,通过卫星或无人机搭载的光学传感器获取森林区域的实时影像。随后,运用图像处理算法对影像中的火焰、烟雾等火灾典型特征进行识别与分析。通过对比时序影像中的变化区域,可有效推断火灾发生的概率。在实际工程中,需对原始图像进行预处理,包括灰度变换、滤波降噪以及边缘提取等操作,以提升火灾特征识别的准确性与鲁棒性。 在Matlab环境下,图像处理任务主要依赖其内置的图像处理工具箱。该工具箱提供了完备的函数接口,支持从图像读入、预处理、特征提取到最终判别的全流程实现。本代码正是基于此工具箱构建,其参数化设计允许使用者根据具体环境条件(如光照、地形)调整关键参数,从而实现最优检测性能。 以下对代码中的核心环节进行详细剖析: * **图像预处理阶段**:代码首先将彩色图像转换为灰度图像,以简化计算复杂度。随后,采用中值滤波或高斯滤波等算法消除采集过程中引入的噪声。最后,通过Canny或Sobel算子进行边缘检测,以强化火焰或烟雾的轮廓特征。 * **特征提取阶段**:该阶段的核心是运用阈值分割技术。通过设定动态或固定的阈值,将疑似火灾区域从复杂的背景中分离出来,形成二值化图像。此过程是后续火灾判别的关键前提。 * **判别与决策阶段**:基于提取出的特征区域,代码进一步分析其面积、形状、纹理等属性,并与预设的火灾模型进行比对,最终输出火灾检测结果。 值得强调的是,本代码遵循层次化、模块化的编程思想,不仅便于开发者理解与二次开发,也极适合作为教学范例。对于涉足计算机、电子信息工程或数学领域的学生而言,该项目能有效融合理论与实践,显著提升其解决实际工程技术问题的能力。 此外,配套的案例数据免除了用户自行搜集训练样本的繁琐过程,使得用户能直接运行程序并观察效果。这种设计极大降低了学习曲线,尤其利于初学者快速掌握基于图像处理的森林火灾检测技术。 综上所述,本程序是一套功能完备、适用性广的森林火灾检测工具。其高度的参数化能力、详尽的注释说明以及多层次的应用场景,使其无论作为教学研究还是工程应用,均展现出不俗的实用价值。 资源来源于网络分享,仅用于学习交流使用,请勿用于商业,如有侵权请联系我删除!

SCI复现基于纳什博弈的多微网主体电热双层共享策略研究(Matlab代码实现)

SCI复现基于纳什博弈的多微网主体电热双层共享策略研究(Matlab代码实现)

【SCI复现】基于纳什博弈的多微网主体电热双层共享策略研究(Matlab代码实现)

EURO____.DWG.rar

EURO____.DWG.rar

CAD缺少相关字体时,图纸中的文字会出现缺失或乱码。下载所需字体并复制到 AutoCAD 的 Fonts 文件夹后,即可正常显示。

机械制造技术基础课程设计(叉杆零件的加工工艺规程及加工孔Φ20的专用夹具设计).rar

机械制造技术基础课程设计(叉杆零件的加工工艺规程及加工孔Φ20的专用夹具设计).rar

机械制造技术基础课程设计(叉杆零件的加工工艺规程及加工孔Φ20的专用夹具设计).rar

最新推荐最新推荐

recommend-type

学生成绩管理系统C++课程设计与实践

资源摘要信息:"学生成绩信息管理系统-C++(1).doc" 1. 系统需求分析与设计 在进行学生成绩信息管理系统开发前,首先需要进行系统需求分析,这是确定系统开发目标与范围的过程。需求分析应包括数据需求和功能需求两个方面。 - 数据需求分析: - 学生成绩信息:需要收集学生的姓名、学号、课程成绩等数据。 - 数据类型和长度:明确每个数据项的数据类型(如字符串、整型等)和长度,例如学号可能是字符串类型且长度为一定值。 - 描述:详细描述每个数据项的意义,以确保系统能够准确处理。 - 功能需求分析: - 列出功能列表:用户界面应提供清晰的操作指引,列出所有可用功能。 - 查询学生成绩:系统应能通过学号或姓名查询学生的成绩信息。 - 增加学生成绩信息:允许用户添加未保存的学生成绩信息。 - 删除学生成绩信息:能够通过学号或姓名删除已经保存的成绩信息。 - 修改学生成绩信息:通过学号或姓名修改已有的成绩记录。 - 退出程序:提供安全退出程序的选项,并确保所有修改都已保存。 2. 系统设计 系统设计阶段主要完成内存数据结构设计、数据文件设计、代码设计、输入输出设计、用户界面设计和处理过程设计。 - 内存数据结构设计: - 使用链表结构组织内存中的数据,便于动态增删查改操作。 - 数据文件设计: - 选择文本文件存储数据,便于查看和编辑。 - 代码设计: - 根据功能需求,编写相应的函数和模块。 - 输入输出设计: - 设计简洁明了的输入输出提示信息和操作流程。 - 用户界面设计: - 用户界面应为字符界面,方便在命令行环境下使用。 - 处理过程设计: - 设计数据处理流程,确保每个操作都有明确的处理逻辑。 3. 系统实现与测试 实现阶段需要根据设计阶段的成果编写程序代码,并进行系统测试。 - 程序编写: - 完成系统设计中所有功能的程序代码编写。 - 系统测试: - 设计测试用例,通过测试用例上机测试系统。 - 记录测试方法和测试结果,确保系统稳定可靠。 4. 设计报告撰写 最后,根据系统开发的各个阶段,撰写详细的设计报告。 - 系统描述:包括问题说明、数据需求和功能需求。 - 系统设计:详细记录内存数据结构设计、数据文件设计、代码设计、输入/输出设计、用户界面设计、处理过程设计。 - 系统测试:包括测试用例描述、测试方法和测试结果。 - 设计特点、不足、收获和体会:反思整个开发过程,总结经验和教训。 时间安排: - 第19周(7月12日至7月16日)完成项目。 - 7月9日8:00到计算机学院实验中心(三楼)提交程序和课程设计报告。 指导教师和系主任(或责任教师)需要在文档上签名确认。 系统需求分析: - 使用表格记录系统需求分析的结果,包括数据项、数据类型、数据长度和描述。 - 分析数据项如学生成绩信息、状态器、链表节点等,确定其属性和行为。 以上就是文档中提到的学生成绩信息管理系统开发的关键知识点。开发此类系统需要熟练掌握C++编程基础,了解面向对象的程序设计思想,以及熟悉文件操作和链表等数据结构的应用。此外,良好的软件开发流程意识、测试意识和文档撰写能力也是必不可少的。
recommend-type

别再手动拖拽了!用Lumerical脚本批量创建FDTD仿真结构(附完整代码)

# 告别低效建模:Lumerical脚本自动化实战指南 在光子学仿真领域,时间就是科研生命线。当同行还在GUI界面里反复点击菜单时,你已经用脚本批量生成了20组参数化结构——这不是未来场景,而是每位FDTD用户都应该掌握的基础生产力革命。本文将彻底改变你与Lumerical的交互方式,从手动拖拽的农耕时代,跃迁到自动化建模的工业文明。 ## 1. 为何脚本建模是必然选择 2019年Nature Photonics的一项研究显示,科研工作者在仿真工具上平均浪费37%的时间在重复性操作上。对于需要参数扫描的纳米光学结构设计,这个数字可能更高。手动创建10个不同尺寸的纳米柱阵列意味着: -
recommend-type

Java邮件解析任务中,如何安全高效地提取HTML邮件内容并避免硬编码、资源泄漏和类型转换异常?

<think>我们被要求优化一段Java代码,该代码用于处理邮件(特别是来自特定发件人的构建通知邮件)。代码的主要问题包括: 1. 重复获取邮件内容:在检查MIME类型后,多次调用`msg[i].getContent()`,这可能导致性能问题或流关闭异常。 2. 类型转换问题:直接将邮件内容转换为`Multipart`而不进行类型检查,可能引发`ClassCastException`。 3. 代码结构问题:逻辑嵌套过深,可读性差,且存在重复代码(如插入邮件详情的操作在两个地方都有)。 4. 硬编码和魔法值:例如在解析HTML表格时使用了硬编码的索引(如list3.get(10)),这容易因邮件
recommend-type

RH公司应收账款管理优化策略研究

资源摘要信息:"本文针对RH公司的应收账款管理问题进行了深入研究,并提出了改进策略。文章首先分析了应收账款在企业管理中的重要性,指出其对于提高企业竞争力、扩大销售和充分利用生产能力的作用。然后,以RH公司为例,探讨了公司应收账款管理的现状,并识别出合同管理、客户信用调查等方面的不足。在此基础上,文章提出了一系列改善措施,包括完善信用政策、改进业务流程、加强信用调查和提高账款回收力度。特别强调了建立专门的应收账款回收部门和流程的重要性,并建议在实际应用过程中进行持续优化。同时,文章也意识到企业面临复杂多变的内外部环境,因此提出的策略需要根据具体情况调整和优化。 针对财务管理领域的专业学生和从业者,本文提供了一个关于应收账款管理问题的案例研究,具有实际指导意义。文章还探讨了信用管理和征信体系在应收账款管理中的作用,强调了它们对于提升企业信用风险控制和市场竞争能力的重要性。通过对比国内外企业在应收账款管理上的差异,文章总结了适合中国企业实际环境的应收账款管理方法和策略。" 根据提供的文件内容,以下是详细的知识点: 1. 应收账款管理的重要性:应收账款作为企业的一项重要资产,其有效管理关系到企业的现金流、财务健康以及市场竞争力。不良的应收账款管理会导致资金链断裂、坏账损失增加等问题,严重影响企业的正常运营和长远发展。 2. 应收账款的信用风险:在信用交易日益频繁的商业环境中,企业必须对客户信用进行评估,以便采取合理的信用政策,降低信用风险。 3. 合同管理的薄弱环节:合同是应收账款管理的法律基础,严格的合同管理能够保障企业权益,减少因合同问题导致的应收账款风险。 4. 客户信用调查:了解客户的信用状况对于预测和控制应收账款风险至关重要。企业需要建立有效的客户信用调查机制,识别和筛选信用良好的客户。 5. 应收账款回收策略:企业应建立有效的账款回收机制,包括定期的账款跟进、逾期账款的催收等。同时,建立专门的应收账款回收部门可以提升回收效率。 6. 应收账款管理流程优化:通过改进企业内部管理流程,如简化审批流程、提高工作效率等措施,能够提升应收账款的管理效率。 7. 应收账款管理策略的调整和优化:由于企业的内外部环境复杂多变,因此制定的管理策略需要根据实际情况进行动态调整和持续优化。 8. 信用管理和征信体系的作用:建立和完善企业内部信用管理体系和征信体系,有助于企业更好地控制信用风险,并在市场竞争中占据有利地位。 9. 对比国内外应收账款管理实践:通过研究国内外企业在应收账款管理上的不同做法和经验,可以借鉴先进的管理理念和方法,提升国内企业的应收账款管理水平。 综上所述,本文深入探讨了应收账款管理的多个方面,为RH公司乃至其他同类型企业提供了应收账款管理的改进方向和策略,对于财务管理专业的教育和实践都具有重要的参考价值。
recommend-type

新手别慌!用BingPi-M2开发板带你5分钟搞懂Tina Linux SDK目录结构

# 新手别慌!用BingPi-M2开发板带你5分钟搞懂Tina Linux SDK目录结构 第一次拿到BingPi-M2开发板时,面对Tina Linux SDK里密密麻麻的文件夹,我完全不知道从哪下手。就像走进一个陌生的大仓库,每个货架上都堆满了工具和零件,却找不到操作手册。这种困惑持续了整整两天,直到我意识到——理解目录结构比死记硬背每个文件更重要。 ## 1. 为什么SDK目录结构如此重要 想象你正在组装一台复杂的模型飞机。如果所有零件都混在一个箱子里,你需要花大量时间寻找每个螺丝和面板。但如果有分门别类的隔层,标注着"机身部件"、"电子设备"、"紧固件",组装效率会成倍提升。Ti
recommend-type

Java线程池运行时状态怎么实时掌握?有哪些靠谱的监控手段?

<think>我们之前已经讨论过Java线程池监控的多种方法,包括使用第三方工具和自定义监控。现在用户再次询问Java线程池监控方法,我们需要根据引用内容以及之前讨论的内容进行总结和扩展。 引用[1]提到使用JDK自带的监控工具,引用[2]提到了三种常用的线程池创建方式,引用[3]给出了通过ThreadPoolExecutor获取线程池状态的方法。 结合之前回答的内容,我们可以将监控方法分为以下几类: 1. 使用JDK自带工具(如jconsole, jvisualvm)进行监控。 2. 通过编程方式获取线程池状态(如引用[3]所示)。 3. 扩展ThreadPoolExecutor,
recommend-type

桌面工具软件项目效益评估及市场预测分析

资源摘要信息:"桌面工具软件项目效益评估报告" 1. 市场预测 在进行桌面工具软件项目的效益评估时,首先需要对市场进行深入的预测和分析,以便掌握项目在市场上的潜在表现和风险。报告中提到了两部分市场预测的内容: (一) 行业发展概况 行业发展概况涉及对当前桌面工具软件市场的整体评价,包括市场规模、市场增长率、主要技术发展趋势、用户偏好变化、行业标准与规范、主要竞争者等关键信息的分析。通过这些信息,我们可以评估该软件项目是否符合行业发展趋势,以及是否能满足市场需求。 (二) 影响行业发展主要因素 了解影响行业发展的主要因素可以帮助项目团队识别市场机会与风险。这些因素可能包括宏观经济环境、技术进步、法律法规变动、行业监管政策、用户需求变化、替代产品的发展、以及竞争环境的变化等。对这些因素的细致分析对于制定有效的项目策略至关重要。 2. 桌面工具软件项目概论 在进行效益评估时,项目概论部分提供了对整个软件项目的基本信息,这是评估项目可行性和预期效益的基础。 (一) 桌面工具软件项目名称及投资人 明确项目名称是评估效益的第一步,它有助于区分市场上的其他类似产品和服务。同时,了解投资人的信息能够帮助我们评估项目的资金支持力度、投资人的经验与行业影响力,这些因素都能间接影响项目的成功率。 (二) 编制原则 编制原则描述了报告所遵循的基本原则,可能包括客观性、公正性、数据的准确性和分析的深度。这些原则保证了报告的有效性和可信度,同时也为项目团队提供了评估标准。基于这些原则,项目团队可以确保评估报告的每个部分都建立在可靠的数据和深入分析的基础上。 报告的其他部分可能还包括桌面工具软件的具体功能分析、技术架构描述、市场定位、用户群体分析、商业模式、项目预算与财务预测、风险分析、以及项目进度规划等内容。这些内容的分析对于评估项目的整体效益和潜在回报至关重要。 通过对以上内容的深入分析,项目负责人和投资者可以更好地理解项目的市场前景、技术可行性、财务潜力和潜在风险。最终,这些分析结果将为决策提供重要依据,帮助项目团队和投资者进行科学合理的决策,以期达到良好的项目效益。
recommend-type

告别遮挡!UniApp中WebView与原生导航栏的和谐共处方案(附完整可运行代码)

# UniApp中WebView与原生导航栏的深度协同方案 在混合应用开发领域,WebView与原生组件的和谐共处一直是开发者面临的经典挑战。当H5的灵活遇上原生的稳定,如何在UniApp框架下实现两者的无缝衔接?这不仅关乎视觉体验的统一,更影响着用户交互的流畅度。让我们从架构层面剖析这个问题,探索一套系统性的解决方案。 ## 1. 理解UniApp页面层级结构 任何有效的布局解决方案都必须建立在对框架底层结构的清晰认知上。UniApp的页面渲染并非简单的"HTML+CSS"模式,而是通过原生容器与WebView的协同工作实现的复合体系。 典型的UniApp页面包含以下几个关键层级:
recommend-type

OSPF是怎么在企业网里自动找最优路径并分区域管理的?

### OSPF 协议概述 开放最短路径优先 (Open Shortest Path First, OSPF) 是一种内部网关协议 (IGP),用于在单一自治系统 (AS) 内部路由数据包。它基于链路状态算法,能够动态计算最佳路径并适应网络拓扑的变化[^1]。 OSPF 的主要特点包括支持可变长度子网掩码 (VLSM) 和无类域间路由 (CIDR),以及通过区域划分来减少路由器内存占用和 CPU 使用率。这些特性使得 OSPF 成为大型企业网络的理想选择[^2]。 ### OSPF 配置示例 以下是 Cisco 路由器上配置基本 OSPF 的示例: ```cisco-ios rout
recommend-type

UML建模课程设计:图书馆管理系统论文

资源摘要信息:"本文档是一份关于UML课程设计图书管理系统大学毕设论文的说明书和任务书。文档中明确了课程设计的任务书、可选课题、课程设计要求等关键信息。" 知识点一:课程设计任务书的重要性和结构 课程设计任务书是指导学生进行课程设计的文件,通常包括设计课题、时间安排、指导教师信息、课题要求等。本次课程设计的任务书详细列出了起讫时间、院系、班级、指导教师、系主任等信息,确保学生在进行UML建模课程设计时有明确的指导和支持。 知识点二:课程设计课题的选择和确定 文档中提供了多个可选课题,包括档案管理系统、学籍管理系统、图书管理系统等的UML建模。这些课题覆盖了常见的信息系统领域,学生可以根据自己的兴趣或未来职业规划来选择适合的课题。同时,也鼓励学生自选题目,但前提是该题目必须得到指导老师的认可。 知识点三:课程设计的具体要求 文档中的课程设计要求明确了学生在完成课程设计时需要达到的目标,具体包括: 1. 绘制系统的完整用例图,用例图是理解系统功能和用户交互的基础,它展示系统的功能需求。 2. 对于负责模块的用例,需要提供详细的事件流描述。事件流描述帮助理解用例的具体实现步骤,包括主事件流和备选事件流。 3. 基于用例的事件流描述,识别候选的实体类,并确定类之间的关系,绘制出正确的类图。类图是面向对象设计中的核心,它展示了系统中的数据结构。 4. 绘制用例的顺序图,顺序图侧重于展示对象之间交互的时间顺序,有助于理解系统的行为。 知识点四:UML(统一建模语言)的重要性 UML是软件工程中用于描述、可视化和文档化软件系统各种组件的设计语言。它包含了一系列图表,这些图表能够帮助开发者和设计者理解系统的设计,实现有效的通信。在课程设计中使用UML建模,不仅帮助学生更好地理解系统设计的各个方面,而且是软件开发实践中常用的技术。 知识点五:UML图表类型及其应用 在UML建模中,常用的图表包括: - 用例图(Use Case Diagram):展示系统的功能需求,即系统能够做什么。 - 类图(Class Diagram):展示系统中的类以及类之间的关系,包括继承、关联、依赖等。 - 顺序图(Sequence Diagram):展示对象之间随时间变化的交互过程。 - 状态图(State Diagram):展示一个对象在其生命周期内可能经历的状态。 - 活动图(Activity Diagram):展示业务流程和工作流中的活动以及活动之间的转移。 - 组件图(Component Diagram)和部署图(Deployment Diagram):分别展示系统的物理构成和硬件配置。 知识点六:面向对象设计的核心概念 面向对象设计(Object-Oriented Design, OOD)是软件设计的一种方法学,它强调使用对象来代表数据和功能。核心概念包括: - 抽象:抽取事物的本质特征,忽略非本质的细节。 - 封装:隐藏对象的内部状态和实现细节,只通过公共接口暴露功能。 - 继承:子类继承父类的属性和方法,形成层次结构。 - 多态:允许使用父类类型的引用指向子类的对象,并能调用子类的方法。 知识点七:图书管理系统的业务逻辑和功能需求 虽然文档中没有具体描述图书管理系统的功能需求,但通常这类系统应包括如下功能模块: - 用户管理:包括用户的注册、登录、权限分配等。 - 图书管理:涵盖图书的入库、借阅、归还、查询等功能。 - 借阅管理:记录借阅信息,跟踪借阅状态,处理逾期罚金等。 - 系统管理:包括数据备份、恢复、日志记录等维护性功能。 通过以上知识点的提取和总结,学生能够对UML课程设计有一个全面的认识,并能根据图书管理系统课题的具体要求,进行合理的系统设计和实现。