Welcome to Python cheatsheet!

• Python 基础小抄
  • Python 命名规范
  • 使用 __future__ 向后移植（backport） 特性
  • 查看对象属性
  • 定义 __doc__ 方法
  • 检查实例类型
  • 检查、获取、赋值属性
  • 继承检查
  • 查询所有 global 变量
  • 检查 callable
  • 获取方法名、类名
  • __new__ & __init__
  • 菱形继承问题
  • 类呈现方法
  • 长字符串分割
  • 优雅地 获取列表元素
  • 优雅地 获取字典元素
  • 优雅地 给列表、字典赋值
  • 命名元组（NamedTuple）
  • __iter__ - 代理迭代器
  • 像迭代器一样使用生成器
  • 仿写列表
  • 仿写字典
  • 仿写矩阵乘法
  • 装饰器
  • 带参数的装饰器
  • for-else 语句
  • try-else 语句
  • Lambda 表达式
  • 不定参数 - (*args, **kwargs)
  • type() 声明（创建） class
  • Callable 对象
  • 上下文管理 - with 语句
  • 使用 @contextmanager
  • 用 with 语句打开文件
  • Property - 管理属性
  • 计算属性（延迟加载） - 使用 property
  • 描述器 - 管理属性
  • @staticmethod, @classmethod
  • 抽象方法 - 元类（Metaclass）
  • 常用 Magic 方法
  • 分析 csv
• Python unicode 小抄
  • Encode: unicode 编码转 bytes
  • Decode: bytes 转 unicode 编码
  • 获取 unicode 码位
  • python2 中 str 等价于 byte 类型
  • python3 中 str 等价于 unicode 类型
  • python2 中 str 字符是 byte 字符
  • python3 中 str 字符是 unicode 字符
  • unicode 规整化
• Python generator cheatsheet
  • Glossary of Generator
  • Produce value via generator
  • Unpacking Generators
  • Implement Iterable object via generator
  • Send message to generator
  • yield from expression
  • yield (from) EXPR return RES
  • Generate sequences
  • What RES = yield from EXP actually do?
  • for _ in gen() simulate yield from
  • Check generator type
  • Check Generator State
  • Simple compiler
  • Context manager and generator
  • What @contextmanager actually doing?
  • profile code block
  • yield from and __iter__
  • yield from == await expression
  • Closure in Python - using generator
  • Implement a simple scheduler
  • Simple round-robin with blocking
  • simple round-robin with blocking and non-blocking
  • Asynchronous Generators
  • Asynchronous generators can have try..finally blocks
  • send value and throw exception into async generator
  • Simple async round-robin
  • Async generator get better performance than async iterator
  • Asynchronous Comprehensions
• Python Regular Expression cheatsheet
  • Compare HTML tags
  • re.findall() match string
  • Group Comparison
  • Non capturing group
  • Back Reference
  • Named Grouping (?P<name>)
  • Substitute String
  • Look around
  • Match common username or password
  • Match hex color value
  • Match email
  • Match URL
  • Match IP address
  • Match Mac address
  • Lexer
• Python socket cheatsheet
  • Get Hostname
  • Transform Host & Network Endian
  • IP dotted-quad string & byte format convert
  • Mac address & byte format convert
  • Simple TCP Echo Server
  • Simple TCP Echo Server Via SocketServer
  • Simple SSL TCP Echo Server
  • Simple UDP Echo Server
  • Simple UDP Echo Server Via SocketServer
  • Simple UDP client - Sender
  • Broadcast UDP Packets
  • Simple UNIX Domain Socket
  • Simple duplex processes communication
  • Simple Asynchronous TCP Server - Thread
  • Simple Asynchronous TCP Server - select
  • High-Level API - selectors
  • “socketpair” - Similar to PIPE
  • Sniffer IP packets
  • Sniffer ARP packet
• Python cryptography cheatsheet
  • simple https server
  • check certificate information
  • generate RSA keyfile without passphrase
  • HMAC - check integrity of a message
  • Using DSA to proof of identity
  • Simple Diffie-Hellman key exchange
  • AES CBC mode encrypt and decrypt
  • AES CTR mode encrypt and decrypt
• Python Concurrency Cheatsheet
  • Execute a shell command
  • Create a thread via “threading”
  • Performance Problem - GIL
  • Consumer and Producer
  • Thread Pool Template
  • Using multiprocessing ThreadPool
  • Mutex lock
  • Deadlock
  • Implement “Monitor”
  • Control primitive resources
  • Ensure tasks has done
  • Thread-safe priority queue
  • Multiprocessing
  • Custom multiprocessing map
  • Graceful way to kill all child processes
  • Simple round-robin scheduler
  • Scheduler with blocking function
  • PoolExecutor
  • What “with ThreadPoolExecutor” doing?
  • Future Object
  • Future error handling
• Python SQLAlchemy Cheatsheet
  • Set a database URL
  • Sqlalchemy Support DBAPI - PEP249
  • Transaction and Connect Object
  • Metadata - Generating Database Schema
  • Inspect - Get Database Information
  • Reflection - Loading Table from Existing Database
  • Get Table from MetaData
  • Create all Tables Store in “MetaData”
  • Create Specific Table
  • Create table with same columns
  • Drop a Table
  • Some Table Object Operation
  • SQL Expression Language
  • insert() - Create an “INSERT” Statement
  • select() - Create a “SELECT” Statement
  • join() - Joined Two Tables via “JOIN” Statement
  • Delete Rows from Table
  • Check Table Existing
  • Create multiple tables at once
  • Create tables with dynamic columns (Table)
  • Object Relational add data
  • Object Relational update data
  • Object Relational delete row
  • Object Relational relationship
  • Object Relational self association
  • Object Relational basic query
  • mapper: Map Table to class
  • Get table dynamically
  • Object Relational join two tables
  • join on relationship and group_by count
  • Create tables with dynamic columns (ORM)
  • Close database connection
  • Cannot use the object after close the session
• Python asyncio cheatsheet
  • What is @asyncio.coroutine?
  • What is a Task?
  • What event loop doing? (Without polling)
  • What asyncio.wait doing?
  • Future like object
  • Future like object __await__ other task
  • Patch loop runner _run_once
  • Put blocking task into Executor
  • Socket with asyncio
  • Event Loop with polling
  • Transport and Protocol
  • Transport and Protocol with SSL
  • What loop.create_server do?
  • Inline callback
  • Asynchronous Iterator
  • What is asynchronous iterator
  • Asynchronous context manager
  • What is asynchronous context manager
  • What loop.sock_* do?
  • Simple asyncio connection pool
  • Simple asyncio UDP echo server
  • Simple asyncio web server
  • Simple HTTPS asyncio web server
  • Simple asyncio WSGI web server
• Python test cheatsheet
  • A simple Python unittest
  • Python unittest setup & teardown hierarchy
  • Different module of setUp & tearDown hierarchy
  • Run tests via unittest.TextTestRunner
  • Test raise exception
  • Pass arguments into a TestCase
  • Group multiple testcases into a suite
  • Group multiple tests from different TestCase
  • Skip some tests in the TestCase
  • Monolithic Test
  • Cross-module variables to Test files
  • skip setup & teardown when the test is skipped
  • Re-using old test code
  • Testing your document is right
  • Re-using doctest to unittest
  • Customize test report
  • Mock - using @patch substitute original method
  • What with unittest.mock.patch do?
  • Mock - substitute open
• Python C API cheatsheet
  • PyObject header
  • Python C API Template
  • PyObject with Member and Methods
• Python Design Pattern in C
  • Decorator in C
  • A Set of Functions
  • Closure in C
  • Generator
  • Context Manager in C
  • Tuple in C
  • Error Handling
  • Simple try: exp except: exp finally: in C
  • Simple coroutine in C
  • Keyword Arguments in C
  • Function “MAP”
  • foreach in C
  • Simple OOP in C