Other articles

1. Better Python Iterators

   Pyhton can convert most (all) lists/collections into iterator objects, this is done by calling iter() ie

   num_list = [1, 2 …

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2. Packaging Python Projects

   How to package a pythin script or project for distribution. Offical Docs are [here][python_package]. Packaging for pip requires use …

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3. Pelican New Post script

   In the aim of keeping the navigation of the Blog posts clean, I have limited my self to a few …

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4. Python Base Types

   Making notes as I work through Dr Chucks Python for Everyone course on Coursera.

   There are 3 main types in …

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5. Modify Pelican theme

   First figure out which theme you are using. List installed themes via:

   % pelican-themes -l
   simple
   notmyidea
   

   pelicanconf.py does not …

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6. Pelican Site add Tags and Categories list

   I think it improves website usability when they are navigatable via the URL.

   For example when viewing Posts under the …

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7. Python Regular Expressions

   Python Regular Expressions Quick Guide:

   ^        Matches the beginning of a line
   $        Matches the end of the line
   .        Matches any character …

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8. Pyhton_virtual_env

   Creating/Setup a pyhton virtual enviroment called 'venv'

   python3 -m venv venv
   

   Load the virtual env called venv

   source venv …

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9. Convolution in Python

   Convolution in Python, for merging filter responses, creating pascals triangle ...

   import numpy as np
   
   a= np.array([1,1])
   b …

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10. Perforce Update files in a Shelve

    Perforce can temporarily checkins of changes that you might want to share with others before fully commiting them to the …

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11. Python merge PDFs

    Using python script to merge pdfs together.

    Install package

    pip install pypdf
    

    Script:

    from pypdf import PdfWriter
    
    pdfs = ['file1.pdf …

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12. Pythonista pip install pelican

    On the journey towards publish static site generator blog posts from iPadOS, my next step after installing stash on pythonista …

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13. Pythonista using stash for pip

    Installing stash on pythonista

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14. Python read a CSV file

    Python example for reading data from a csv file.

    import csv
    with open(data.csv', newline='') as csvfile:
        spamreader = csv …

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15. Python Sinewave

    Create and plot a sinewave in python

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16. "Find your ruby gems path"

     ruby -r rubygems -e "p Gem.path"
    

    From Giles Bowkett.

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17. "error: storage class specified for parameter"

    error: storage class specified for parameter
    

    There is probably a missing semicolon ; in a header file! Just written my first …

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18. "Octopress categories with different styles"

    As I use the code blocks for ingredient lists on my recipe pages I wanted to have a different style …

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19. "Licence Types and Short Identifiers"

    Some time ago gemspec files for ruby gems added the ability to specify the short identifier for the license type …

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20. "Ruby Methods and Splat"

    Ruby methods can set default values for optional arguments:

    def commit(path=Dir.pwd)
    

    To take an optional number of …

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21. "Thor Adding --verbose"

    With a command line Ruby application using Thor for the option parsing I want to be able to run:

    $ thor_app …

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22. "Thor Variable Arguments"

    Thor is a Ruby Gem, which allows you to build command line applications which accept commands, in the same way …

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23. "Ruby Print Array"

    puts and to_s could be better:

    a = [1, 2, 3]
    puts a
    > 1
    > 2
    > 3
    
    puts a.to_s
    > [1, 2 …

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24. "Ruby iterate over lines in a string"

    str.each_line do |line|
      #do something with line
    end
    

    Source.

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25. "Edit Octopress Posts"

    Creating new posts in Octopress is rake new_post["Edit Posts"] which outputs the created filename.

    Posts are prefixed with date …

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26. "Monkey Patch Octopress"

    Based on post_filters by imathis.

    First Move the original method out the way with alias_method then create a new method …

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27. "OS X Handbrake install libdvdcss (Decryption)"

    1. Go to the Videolan website and download and run the libdvdcss.pkg.

    2. Switch VLC preference, Advanced, uncheck Dvd-Video use libdvdnav …

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28. "Ruby Evaluate Envvars in string."

    In ruby Dir.entries takes a path and returns a list of its contents. However it does not deal with …

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29. "Ruby: optionally add path separator"

    I was wanting to use Dir.glob to get a file list and wanted to do Dir.glob( path + '*') but …

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30. "Add about page to Octopress"

    To add static about page to octopress blog, assuming that octopress has been already setup:

    Create the page from the …

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31. "JavaScript Net Curtain"

    Normally this would just end up on my link blog, but thought it was worthy of a proper mention.

    A …

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32. "Algebra : Properties of Real (ℝ) Numbers"

    Commutative

    Configurable order of numbers:

    x+y = y+x
    xy  = yx
    

    Associative

    Order that multiplication is applied :

    (x+y)+z …

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33. "Ruby duck typing Strings and Arrays"

    How to get method which handles a single string input or an array of strings?

    Splat *

    * turns single strings into …

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34. "Print nested array structures in table format"

    Problem

    Take an array of arrays and format it for displaying to the terminal or outputting to a text file …

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35. "Converting flat structure into a nested structure"

    Given a flat hierarchy of data comprising level and a label, aim to nest the lower level of objects in …

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36. "Calculating Regression Coefficients in R"

    For this example we will have a data file with two columns of data labelled A and B. For example …

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37. "Mountain Lion Setup, Part 2 Homebrew & RVM"

    Following on from Macbook Pro Setup, Now it is time to install some of the command line tools.

    I have …

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38. "Mountain Lion Setup, Part 1 : Upgrade Lion"

    MacBook Pro with Lion arrives, before installing any other software apply for the Up-to-Date Programme for free a mountain lion …

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39. "Web Automation with Watir"

    Watir is a web testing framework implemented in ruby, but can be used for testing or automating any web service …

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40. "Pragmatic Programmers, Dropbox integration"

    After deciding to try out epub on the kindle, as I noticed people are listing epub as an apple format …

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41. "Create And,Or of multiple booleans"

    To reduce an array of Booleans to a single Boolean using enumerables reduce method:

    [true, true, true].reduce( :| ) ## OR
    => true …

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42. "rspec testing exceptions"

    rspec is a testing framework designed to make test-driven development enjoyable and productive. On the recent release of RubyIt I …

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43. "rspec testing exceptions (old post)"

    Correct Post

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44. "Ruby special exception variables made mnemonic"

    In ruby you can catch StandardErrors using begin rescue end

    begin
      #Some thing which might fails
    rescue
      $stderr.puts $!
    end …

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45. "Handle www. and no-www for better google juice"

    There was an interesting post on hacker news recently, safeshepherd suddenly fell off the google for their own name. The …

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46. "Syntax error: Not a valid color stop: Sass::Script::String: white"

    After making a few updates to my site it stopped working after deploying. The issue was that the gem version …

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47. "Minify your HTML from Sinatra"

    There are gzip compression options available but when I looked at this a long time ago I found that the …

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48. "Sinatra application in ./lib and views, public routes not working"

    I have been setting up my recent Sinatra projects with a standard ruby project layout putting all of the application …

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49. "Update your RVM Ruby and migrate gemsets"

    Update RVM

    $ rvm get head
    

    List current versions, and all versions

    $ rvm list
    $ rvm list known
    

    Select the version you …

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50. "Encoding::UndefinedConversionError - "

    Are you running into the following error

    Encoding::UndefinedConversionError - "\xE2" from ASCII-8BIT to UTF-8:
    

    If you are using Ruby and …

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51. "CSS (Via SASS) Seperating Colour and Position"

    While working on this site I wanted to find a simple way of trying out multiple stylesheets for different colour …

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52. "User selectable stylesheets (Using Sinatra)"

    Working on my site design I thought it would be nice to have user selectable stylesheets, say a black text …

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53. "matrix: A Ruby Standard Library"

    Originally written as an assignment for Ruby Mendicant University.

    matrix is part of the Ruby Standard Library

    Usage

    A note …

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54. "Ruby get a users real name"

    There does not appear to be a nice way to get a current users real name in ruby. The best …

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55. "Ruby send message to stderr"

    When creating applications normal messages should go to stdout and error messages should go to stderr, unfortunately there is not …

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56. "Suppressing Warnings in Ruby Scripts"

    Suppressing warnings is usually a bad idea but if you understand the risk and want to carry on regardless. When …

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57. "Setting Ruby Defaults '||' vs 'fetch(){}'"

    There is a very good presentation Confident Code by Avdi Grimm author of http://exceptionalruby.com/. Previously presented at Cascadia …

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58. "Benchmarking Ruby, explicit vs implicit returns"

    Back in 2009 barkingiguana wrote about how explicit returns 'return "String"' was slower than an implicit return, ie just letting …

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59. "Arrays 3, write idiomatic Ruby"

    Previous posts arrays and arrays2

    Based on a post by barkingiguana, some idiomatic ruby ways to handle arrays. Ruby tries …

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60. "Ruby Search and Replace Script."

    A small standalone script that search through a file doing text substitutions.

    1 2 3 4 5 6 7 8 …

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61. "warning: already initialized constant"

    Do you some times see:

    FileUtils.rb:93: warning: already initialized constant OPT_TABLE
    FileUtils.rb:1176: warning: already initialized constant …

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62. "Ruby Arrays Concatenation and Subtraction"

    Building on my original Ruby Arrays article a few more things you can do with Ruby Arrays.

    Concatenation

    a = [1 …

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63. "Ruby Blocks for better code reuse"

    While working on some disk space / folder structure scripts I had several functions which hierarchically search the disk then performed …

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64. "Get latest Ruby 1.9.2 build with RVM"

    Ruby 1.9.2-p290 released, if you have RVM installed updating to the latest release is easy

    rvm get head …

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65. "Ideas 1st July to the 3rd July"

    When working with HDLs (Hardware Description Languages) there a few things that could be improved/made easier:

    Renaming a file …

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66. "Ruby Basic File Read and Write"

    Read text file with one line:

    Write text with one line :

    Explanation and other ways

    When reading a text file …

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67. "uninitialized constant Compass::Logger"

    Working on a joint project an error started showing up when trying to perform migrations.

    $ rake db:migrate VERSION=0 …

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68. "Sinatra ActiveRecord DB config on Heroku"

    To make an automatic ActiveRecord database connection using ENV['DATABASE_URL'] The following snippet can be used:

    From ActiveRecord 3.2 …

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69. "Ruby script connect to DB using database.yml"

    To connect to a rails style DB config outside of the normal workflow, or using a database.yml in a …

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70. "Ruby Arrays, Part 1"

    Some uses of Arrays that were not apparent at first.

    Enumeration

    each is the basic enumerator method but there is …

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71. "Obnoxious gem warnings"

    recenlty after updating rubygems Istarted getting a lot of warning like this when running ruby or executable gems:

    NOTE: Gem …

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72. "Recent issue with building Gems"

    When running gem build on a new library I have been working on I started getting the following error:

    [ruby_svg_light …

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73. "Behaviour and State"

    Classes are a basic Object Orientated Structure which encapsulate state and behaviour. Some times you just require to capture state …

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74. "Better Open Source Project Setup, with RVM & Bundler"

    Based on 'Raise the bar, lower the pressure' given by Durran Jordan at ScotRubyConf 2011.

    There has been some debate …

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75. "Schwartzian Transform"

    I recently heard about the Schwartzian transform, which is a sorting idiom from perl. It allows an array of objects …

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76. "Ruby CLI user input using gets"

    Using a while true loop with 'gets' and a case statement, can create a compact command line interface for ruby …

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77. "Amaras Site Updates"

    I have just finished some minor updates to the site. The largest is the move to Droid Fonts, Google Fonts …

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78. "ORM(Activerecord) or Ruby Sort"

    Based on an old Article I wrote, investigating incase sensitive sorting performance.

    I have an active record model call Tag …

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79. "Activerecord Find All/Multiple"

    Using Tags (An active record model) to find tags by the tag property:

    Tag.find_by_tag("Ruby")
    Ruby
    
    Tag.find_by_tag(["Ruby …

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80. "gem permissions on WebFaction"

    After making a few updates to my site I decided to upgrade the version of sinatra I was using in …

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81. "Sinatra regex routes"

    The routes for my site have been growing since adding pagination (/articles/older/) and tag filtering. As well as the …

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82. "Ruby Block Selection in Vim (Plugin)"

    A new very cool plugin for Rubyists using Vim. RubyBlock TextObjects created by Drew Neil from Vimcasts.org. Once installed …

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83. "Put methods not working with Classy Sinatra apps"

    Since moving to Classy Sinatra applications I have not been able to get put and delete methods to work correctly …

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84. "rake aborted! undefined method `info' for nil:NilClass"

    I am currently switching between runing migrations locally on an sqlite3 database and postgres for production on Heroku.

    When switching …

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85. "Sinatra Heroku and config.ru"

    Rack applications often require a config.ru for deployment. The standard config.ru for classic sinatra applications is well documented …

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86. "Sinatra Session Extension"

    I have just started to use a sinatra extensions called Sinatra Session. The write up on the main site is …

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87. "Sinatra reload source file changes in development mode"

    Sinatra Reloader is a sinatra extension which reloads source files while in development mode, this functionality was removed from base …

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88. "Ruby each or delete_if"

    In ruby some times you want to iterate over an array and remove items that meet certain conditions, if using …

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89. "Storing secret keys in Ruby config files an approach"

    I have for a while wondered about an ideal (good) approach to storing api keys in config files in ruby …

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90. "Ruby Regular Expressions Lookahead / Lookbehind"

    I recently discovered a feature of regular expressions called lookahead. This means for a match the lookahead must exist but …

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91. "Ruby Time save and Restore (serialise)"

    One method to save a time and restore it correctly:

    def get_time_run
    ## File Access based on
    ## http://rubylearning.com/satishtalim …

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92. "Error: NoMethodError: undefined method `compact' for nil:NilClass"

    When running a sequel migration I kept getting this error:
    Error: NoMethodError: undefined method `compact' for nil:NilClass

    My setup …

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93. "Active Record attributes simplify update and create."

    In Active Record when updating records I used to have an very manual process to this some thing like:

    @todo …

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94. "Active Record create unique or return existing element"

    When working with databases it is often a requirement to have unique elements (columns) which are not the primary key …

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95. "Activerecord queries on table joins"

    An example of joining tables through active record models. There is a good tutorial on the basics of Activerecord joins …

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96. "Benchmark your website for load times."

    I have been wondering how to do this for a while and accidentally discovered it while perusing this heroku page …

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97. "@philip_roberts taught me a thing or two about CSS"

    CSS or Cascading Style Sheets are used for styling html elements. HTML elements can have id's, which must be unique …

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98. "Get client IP on Heroku"

    I have been trying to use the GeoIP Rack App, by copying this gist in my Rack stack with a …

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99. "Sinatra running on Heroku"

    For running small webapps heroku is free. The real attraction is the simplicity of deployment, if you are use to …

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100. "jQuery clear form on focus and restore on exit"

     I used this as a jQuery reference to hide and show default text in forms.

     <head>
        <script type=”text/javascript …

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101. "WebFaction problems restarting nginx"

     After updating my website on webfaction nginx kept saying permission denied and when I tried to view my site I …

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102. "Creating executable gems"

     This is not necessarily the correct way of creating executable gems but a method which worked for me.

     Assuming we …

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103. "gem install memory_usage"

     Just released my first gem 'memory_usage' Version 0.0.1.

     $ gem install memory_usage
     

     Assuming the gems folder has been set-up …

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104. "64Bit Handbrake for Video Encoding on Mac OS X"

     If you are trying to use the 64 bit version of handbrake on Snow Leopard do not for get that …

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105. "Ruby runnable and includeable"

     I might have just made up includable, but I like it.

     Some times you have written a ruby script (using …

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106. "Super simple Ruby list directory contents"

     A very simple Ruby way for listing files in a directory is the glob function:

     1 2 3 4 5 …

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107. "413 Request Entity Too Large"

     The '413 Request Entity Too Large' Error message is because you have filled in a form and are submitting it …

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108. "Installing Ruby Enterprise on Mac OS X"

     Download ruby enterprise and follow instructions on page. The exact commands I used are:

     $ cd ~/bin
     $ wget http://rubyforge.org …

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109. "Ruby Memory Issue on Web Faction"

     I while ago I made a post about installing ruby 1.9 on my webfaction shared host. They then pointed …

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110. "Sinatra File Upload"

     A simple Sinatra web app to upload a single file. Also available as a gist, based on http://pastie.caboo …

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111. "Webfaction new user with access to their own site"

     With Webfaction you can create new users with there own home area but there is no straight forward way to …

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112. "Ruby, Ruby, Ruby, why are you so wierd at times?"

     This feature of ruby keeps catching me out as the behaviour is quite unexpected (by me).

     I can use a …

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113. "Testing tweets from Production server This should be working!"

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114. "Ruby incase sensitive sort"

     Ruby has a .sort method which sorts basic objects. it is case sensitive though so Zebra is before apple. Using …

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115. "Ruby and gemspec"

     I have just forked and cloned a project on github and discovered *.gemspec files. They are a nice way of …

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116. "Ruby .nil? tests fail ? you really want ||="

     I recently discovered ||= in ruby. Its main use is for initialising a variable if it does not already exists, this …

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117. "Installing the ruby gem twitter on webfaction"

     [Update]
     As this is a long post I am putting this update at the top. If you just want to …

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118. "gem install with out the docs"

     When I install gems on my server I do not get any of the documentation which is normally 3-5 times …

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119. "Sinatra blog retrieving next and previous ids"

     When displaying blog/articles it is often nice to have previous and next posts. Simply -1 +1 from the current …

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120. "Sequel ORM Migrations"

     Available as a gist a Sequel Migration to rename a database column.

     ## Command line to apply Migration
     #sequel -m ./db …

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121. "Amaras Finally Online"

     Just a short first note to announce the fact that the site is finally up.

     We are running on WebFaction …

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122. "FourThirds Sinatra RESTful example"

     This is an example of efficient use of views in Sinatra covering RESTful actions. This is a copy of my …

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123. "Ruby include (require) local files"

     Also a gist on github. This is an example of how you can require files in a relative path to …

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124. "Ruby Logger"

     Ruby has a nice logging function,

     Update once example of rotating logs finished

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125. "Ruby Performance Measure"

     Also available as a gist. Very simple way of measuring execution time in seconds using Ruby

     1 2 3 4 …

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126. "Ruby run (execute) command line"

     Also a gist on github. This code snippet is an example of how to execute a command line argument in …

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127. "Sinatra 1.0 Released"

     Sinatra 1.0 has been released!

     When you install the new version the old one are still left behind. This …

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128. "Sinatra and compass sending compressed cached CSS"

     I have previously mentioned on blogger how to use Compass and SASS with Sinatra for rendering the stylesheets.

     I have …

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129. "GitX"

     Git has a hand full of GUIs available on Mac OS X, gitk proved a little tricky to use but …

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130. "Ruby Time Formats"

     I have been playing around with getting my blog posts timestamped I found the Ruby Time Docs to be very …

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