#37 Rule over the shells with Sultan

Brian #1: New URL for Python Developer’s Guide

• How to contribute to CPython

Some really useful links that I hadn’t noticed before. Also great ideas to include in a contributing guide for any large open source project:

• Core developers and contributors alike will find the following guides useful:
  • How to Contribute to Open Source (from https://opensource.guide)
  • Building Welcoming Communities (from https://opensource.guide)
• Guide for contributing to Python:
  • Getting Started
  • Where to Get Help
  • Lifecycle of a Pull Request
  • Running & Writing Tests
  • Beginner tasks to become familiar with the development process
  • Helping with Documentation
  • Increase Test Coverage
  • Advanced tasks for once you are comfortable
  • Silence Warnings From the Test Suite
  • Fixing issues found by the buildbots
  • Fixing “easy” Issues (and Beyond)
  • Using the Issue Tracker and Helping Triage Issues
  • Triaging an Issue
  • Experts Index
  • Following Python’s Development
  • How to Become a Core Developer
  • Committing and Pushing Changes
  • Development Cycle
  • Continuous Integration
  • Git Bootcamp and Cheat Sheet

Michael #2: Sultan: Command and Rule Over Your Shell

• Python package for interfacing with command-line utilities, like yum, apt-get, or ls, in a Pythonic manner

Simple example

from sultan.api import Sultan
s = Sultan()
s.sudo("yum install -y tree").run()

Better in a context manager:

from sultan.api import Sultan

with Sultan.load(sudo=True) as s:
  s.yum("install -y tree").run()

Even works remotely:

from sultan.api import Sultan

with Sultan.load(sudo=True, hostname="myserver.com") as sultan:
  sultan.yum("install -y tree").run()

Brian #3: Flake8Lint

• Sublime Text plugin for lint Python files.
• Includes these linters and style checkers:
  • Flake8 (used in "Python Flake8 Lint") is a wrapper around these tools:
  • pep8 is a tool to check your Python code against some of the style conventions in PEP8.
  • PyFlakes checks only for logical errors in programs; it does not perform any check on style.
  • mccabe is a code complexity checker. It is quite useful to detect over-complex code. According to McCabe, anything that goes beyond 10 is too complex. See Cyclomatic_complexity.
  • There are additional tools used to lint Python files:
  • pydocstyle is a static analysis tool for checking compliance with Python PEP257.
  • pep8-naming is a naming convention checker for Python.
  • flake8-debugger is a flake8 debug statement checker.
  • flake8-import-order is a flake8 plugin that checks import order in the fashion of the Google Python Style Guide (turned off by default).

Michael #4: Magic Wormhole

• Get things from one computer to another, safely.
• A library and a command-line tool named wormhole, which makes it possible to get arbitrary-sized files and directories (or short pieces of text) from one computer to another.
• The two endpoints are identified by using identical "wormhole codes”
• Video from PyCon 2016: https://www.youtube.com/watch?v=oFrTqQw0_3c
• The codes are short and human-pronounceable, using a phonetically-distinct wordlist.
• As a library too: The wormhole module makes it possible for other applications to use these code-protected channels.

Brian #5: Python Virtual Environments Primer

• why do we need virtual environments
• what are they
• how to use them / how do they work
• also
  • virtualenvwrapper
  • using different versions of python
  • pyvenv

Michael #6: How Rust can replace C, with Python's help

• Why Rust? Rust has
  • a type system feature that helps eliminate memory leaks,
  • proper interfaces, called 'traits',
  • better type inference,
  • better support for concurrency,
  • (almost) first-class functions that can be passed as arguments.
• It isn’t difficult to expose Rust code to Python. A Rust library can expose a C ABI (application binary interface) to Python without too much work.
• Some Rust crates (as Rust packages are called) already expose Python bindings to make them useful in Python.
• A new spate of projects are making it easier to develop Rust libraries with convenient bindings to Python – and to deploy Python packages that have Rust binaries
• Rust-CPython:
  • What it is: A set of bindings in Rust for the CPython runtime. This allows a Rust program to connect to CPython, use its ABI, run Python programs through it, and work with representations of Python objects in Rust itself.
  • Who it’s for: Rust programmers who want to hook into CPython and control it from the inside out.
• PyO3
  • What it is: For Rust developers, the PyO3 project provides a basic way to write Rust software with bindings to Python in both directions. A Rust program can interface with Python objects and the Python interpreter, and can expose Rust methods to a Python program in the same way a C module does.
  • Who it’s for: Those writing modules that work closely with the Python runtime, and need to interact directly with it.
• Snaek
  • What it is: Another project in the early stages, Snaek lets developers create Rust libraries that are loaded dynamically into Python as needed, but don’t rely on being linked statically against Python’s runtime.
  • Doesn’t use CTypes but CFFI
  • Who it’s for: Those who want to expose methods written in Rust to a Python script, or for Rust developers who don’t want or need to become familiar with Python.
• And there is a cookiecutter project / template too
  • https://github.com/mckaymatt/cookiecutter-pypackage-rust-cross-platform-publish
  • “A very important goal of the project,” writes its maintainers, “is that it be able to produce a binary distribution (Wheel) which will not require the end user to actually compile the Rust code themselves.”