Welcome to Python cheatsheet!

• Python basic cheatsheet
  • Python Naming Rule
  • Using __future__ backport features
  • Check object attributes
  • Define a function __doc__
  • Check instance type
  • Check, Get, Set attribute
  • Check inheritance
  • Check all global variables
  • Check callable
  • Get function/class name
  • __new__ & __init__
  • The diamond problem
  • Representations of your class behave
  • Break up a long string
  • Get list item SMART
  • Get dictionary item SMART
  • Set a list/dict SMART
  • set operations
  • NamedTuple
  • __iter__ - Delegating Iteration
  • Using Generator as Iterator
  • Emulating a list
  • Emulating a dictionary
  • Decorator
  • Decorator with arguments
  • for: exp else: exp
  • try: exp else: exp
  • Lambda function
  • Option arguments - (*args, **kwargs)
  • type() declare (create) a class
  • Callable object
  • Context Manager - with statement
  • Using @contextmanager
  • Using with statement open file
  • Reading file chunk
  • Property - Managed attributes
  • Computed attributes - Using property
  • Descriptor - manage attributes
  • @staticmethod, @classmethod
  • Abstract method - Metaclass
  • Common Use Magic
  • Parsing csv string
  • Using __slots__ to save memory
  • Using annotation for type hints
  • Using annotation to check type
• New in Python3 cheatsheet
  • print is a function
  • String is unicode
  • New Super
  • Remove <>
  • Not allow from module import * inside function
  • Add nonlocal keyword
  • Extended iterable unpacking
  • General unpacking
  • Function annotations
  • Variable annotations
  • Core support for typing module and generic types
  • Format byte string
  • fstring
  • Suppressing exception
  • Generator delegation
  • async and await syntax
  • Asynchronous generators
  • Asynchronous comprehensions
  • Matrix multiplication
  • Data Classes
  • Built-in breakpoint()
• Python unicode cheatsheet
  • Encode: unicode code point to bytes
  • Decode: bytes to unicode code point
  • Get unicode code point
  • python2 str is equivalent to byte string
  • python3 str is equivalent to unicode string
  • python2 take str char as byte character
  • python3 take str char as unicode character
  • unicode normalization
• 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 through IPv6
  • Disable IPv6 Only
  • Simple TCP Echo Server Via SocketServer
  • Simple TLS/SSL TCP Echo Server
  • Set ciphers on TLS/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
  • Simple Asynchronous TCP Server - poll
  • Simple Asynchronous TCP Server - epoll
  • Simple Asynchronous TCP Server - kqueue
  • High-Level API - selectors
  • Simple Non-blocking TLS/SSL socket via selectors
  • "socketpair" - Similar to PIPE
  • Using sendfile do copy
  • Sending a file through sendfile
  • Linux kernel Crypto API - AF_ALG
  • AES-CBC encrypt/decrypt via AF_ALG
  • AES-GCM encrypt/decrypt via AF_ALG
  • AES-GCM encrypt/decrypt file with sendfile
  • Compare the performance of AF_ALG to cryptography
  • Sniffer IP packets
  • Sniffer TCP packet
  • Sniffer ARP packet
• Python cryptography cheatsheet
  • Simple https server
  • Check certificate information
  • Generate a self-signed certificate
  • Prepare a Certificate Signing Request (csr)
  • Generate RSA keyfile without passphrase
  • Sign a file by a given private key
  • Verify a file from a signed digest
  • Simple RSA encrypt via pem file
  • Simple RSA encrypt via RSA module
  • Simple RSA decrypt via pem file
  • Simple RSA encrypt with OAEP
  • Simple RSA decrypt with OAEP
  • Using DSA to proof of identity
  • Using AES CBC mode encrypt a file
  • Using AES CBC mode decrypt a file
  • AES CBC mode encrypt via password (using cryptography)
  • AES CBC mode decrypt via password (using cryptography)
  • AES CBC mode encrypt via password (using pycrypto)
  • AES CBC mode decrypt via password (using pycrytpo)
  • Ephemeral Diffie Hellman Key Exchange via cryptography
  • Calculate DH shared key manually via cryptography
  • Calculate DH shared key from (p, g, pubkey)
• 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
  • decorator @asynccontextmanager
  • 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
  • Performance of ctypes
  • Error handling when use ctypes
  • Getting File System Type
  • Doing Zero-copy via sendfile
  • 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