#26 How have you automated your life, or CLI, with Python?

Sponsored by rollbar: rollbar.com/pythonbytes

Brian #1: Two part series on interactive terminal applications

Part 1: 4 terminal applications with great command-line UIs

• For Comparison: both ok but could be better
  • MySQL REPL
  • Python REPL
• bpython adds autocompletion and other goodies
  • also check out ptpython as a REPL replacement
• mycli adds context aware completion to MySQL mycli - pgcli for postgress that adds fuzzy search
• fish : like bash, but has better search history

Part 2: 4 Python libraries for building great cli's

• prompt_toolkit - for building a REPL like interface
  • includes command history, auto-suggestion, auto-completion
• click
  • includes pager and ability to launch an editor
• fuzzyfinder - make suggestions
  • article shows how to combine that with prompt_toolkit
• pygments - syntax highlighting

Michael #2: How have you automated your life with python?

• There is something magical about writing code that interacts with the physical world.
• I have a script which runs every 5 minutes between 17:00 and 17:30 which scrapes the train times website and sends me desktop notifications saying whether or not my trains home are delayed / cancelled.
• I recently wrote a quick python script that tells me when my girlfriend comes home: It sniffs the network for DHCP traffic, when her phone joins the wifi network outside it uses the say command to let me know.
• Wrote a script to check if nearby ice cream shops are stocking my favourite (rare) flavour by scanning their menu page for keywords.
• A script to check the drive time too/from work using a route with tolls or without tolls.. to try and save some money when the times aren't too different. Using google maps API and a flask site.
• I have a script that generates weekly status update emails based off my git commit messages and pull requests. It also creates timesheets in Harvest based on the projects I'm assigned.
• I have thrown together some python that automatically controls my reverse-cycle AC system so that it makes optimal use of my solar panels on my roof.

Brian #3: Building a Simple Birthday App with Flask-SQLAlchemy

• Nice simple application with a clear need.
  • Keep track of upcoming birthdays
  • Avoid Faceboook
  • Build a simple Flask app
  • Try SQLAlchemy

Sponsored by Rollbar, try them at rollbar.com/pythonbytes and don't forget to visit their booth at PyCon!

Michael #4: Spelling with Elemental Symbols

• How does it work?
  • Input: "Amputations"
  • Output: "AmPuTaTiONS", "AmPUTaTiONS"
• Generating Character Groupings:
  • 'AmPuTaTiONS' (2,2,2,2,1,1,1)
  • 'AmPUTaTiONS' (2,1,1,2,2,1,1,1)
  • How many are there in general for a given word? fib(n + 1)!
• Addressing Performance Issues: A few attempts don’t add much but
• Memoization: The technique of saving a function's output and returning it if the function is called again with the same inputs. A memoized function only needs to generate output once for a given input. This can be very helpful with expensive functions that are called many times with the same few inputs, but only works for pure functions. → 30% faster
• Algorithms: Switch to directed graphs and recursion, changes O(2^n) to O(n) and time from 16min to 10 sec.
• Learned a great deal along the way. This project introduced:
  • Combinatorics
  • Performance profiling
  • Time complexity
  • Memoization
  • Recursion
  • Graphs and trees

Brian #5: IDE's for beginners

• Recent discussion on Reddit about Thonny
• I have mixed feelings about encouraging beginner IDE's.
  • Mostly negative feelings.
  • And yet there is IDLE, there is Thonny, ...
• Are these useful? Anti-useful?
• Isn't learning a decent editor part of learning to program?

Michael #6: PDF Plumber

• Plumb a PDF for detailed information about each char, rectangle, line, et cetera — and easily extract text and tables.
• Visual debugging with .to_image()
• Extracting tables
  • pdfplumber's approach to table detection borrows heavily from Anssi Nurminen's master's thesis, and is inspired by Tabula. It works like this:
  • For any given PDF page, find the lines that are (a) explicitly defined and/or (b) implied by the alignment of words on the page.
  • Merge overlapping, or nearly-overlapping, lines.
  • Find the intersections of all those lines.
  • Find the most granular set of rectangles (i.e., cells) that use these intersections as their vertices.
  • Group contiguous cells into tables.
  • Check out the demonstrations section.