Just drop `require &#39;irb/completion&#39;` in your irbrc.

If that doesn&#39;t work try bond, http://tagaholic.me/bond/:

       require &#39;bond&#39;; require &#39;bond/completion&#39;

Bond not only improves irb&#39;s completion, http://tagaholic.me/2009/07/22/better-irb-completion-with-bond.html, but also offers an easy dsl for making custom autocompletions.

This is just repeating the information on Cody Caughlan&#39;s comment above so it is easier to find:

either `require &#39;irb/completion&#39;` or add the following to `~/.irbrc`

    IRB.conf[:AUTO_INDENT] = true
    IRB.conf[:USE_READLINE] = true
    IRB.conf[:LOAD_MODULES] = [] unless IRB.conf.key?(:LOAD_MODULES)
    unless IRB.conf[:LOAD_MODULES].include?(&#39;irb/completion&#39;)
      IRB.conf[:LOAD_MODULES] &lt;&lt; &#39;irb/completion&#39;
    end 

This is what worked for me on Mac OS 10.11.5. using rvm. Do the following : 

 1. `sudo gem install bond`
 2. Create the file `.irbrc` in your home directory. `vi ~/.irbrc`
 3. Add the following lines in the `.irbrc` file
```
require &#39;bond&#39; 
Bond.start
```
 
 4. Save and close the file
 5. Open `irb` and use `tab` key to autocomplete



I am working on PIL and need to know if the image quality can be adjusted while resizing or thumbnailing an image. From what I have known is the default quality is set to 85. Can this parameter be tweaked during resizing?

I am currently using the following code:

    image = Image.open(filename)
    image.thumbnail((x, y), img.ANTIALIAS)

The `ANTIALIAS` parameter presumably gives the best quality. I need to know if we can get more granularity on the quality option.

How to adjust the quality of a resized image in Python Imaging Library?

I have a string that looks like this: &quot;9/1/2009&quot;. I want to convert it to a DateTime object (using C#).

This works:

    DateTime.Parse(&quot;9/1/2009&quot;, new CultureInfo(&quot;en-US&quot;));

But I don&#39;t understand why this doesn&#39;t work:

    DateTime.ParseExact(&quot;9/1/2009&quot;, &quot;M/d/yyyy&quot;, null);

There&#39;s no word in the date (like &quot;September&quot;), and I know the specific format, so I&#39;d rather use ParseExact (and I don&#39;t see why CultureInfo would be needed). But I keep getting the dreaded &quot;String was not recognized as a valid DateTime&quot; exception.

Thanks

A little follow up. Here are 3 approaches that work:

    DateTime.ParseExact(&quot;9/1/2009&quot;, &quot;M&#39;/&#39;d&#39;/&#39;yyyy&quot;, null);
    DateTime.ParseExact(&quot;9/1/2009&quot;, &quot;M/d/yyyy&quot;, CultureInfo.InvariantCulture);
    DateTime.Parse(&quot;9/1/2009&quot;, new CultureInfo(&quot;en-US&quot;));

And here are 3 that don&#39;t work:

    DateTime.ParseExact(&quot;9/1/2009&quot;, &quot;M/d/yyyy&quot;, CultureInfo.CurrentCulture);
    DateTime.ParseExact(&quot;9/1/2009&quot;, &quot;M/d/yyyy&quot;, new CultureInfo(&quot;en-US&quot;));
    DateTime.ParseExact(&quot;9/1/2009&quot;, &quot;M/d/yyyy&quot;, null);

So, Parse() works with &quot;en-US&quot;, but not ParseExact... Unexpected?


Why can&#39;t DateTime.ParseExact() parse &quot;9/1/2009&quot; using &quot;M/d/yyyy&quot;

When I use Merb&#39;s built in console, I get tab auto-completion similar to a standard bash prompt.  I find this useful and would like to enable it in non-merb IRB sessions.  How do I get auto-completion in IRB? 

How to enable auto completion in Ruby&#39;s IRB

<p>When I use Merb's built in console, I get tab auto-completion similar to a standard bash prompt.  I find this useful and would like to enable it in non-merb IRB sessions.  How do I get auto-completion in IRB?</p>


Why sometimes I should use block and other times &amp;block inside functions that accept blocks?

Difference between block and &amp;block in Ruby

My `created_at` timestamps are stored in UTC:

    &gt;&gt; Annotation.last.created_at
    =&gt; Sat, 29 Aug 2009 23:30:09 UTC +00:00

How do I convert one of them to &#39;Eastern Time (US &amp; Canada)&#39; (taking into account daylight savings)? Something like:

    Annotation.last.created_at.in_eastern_time


Convert Time from one time zone to another in Rails

I have a rake task to seed an application with random data using the faker gem. However, we also have images (like logos) that we want uploaded in this rake task.

We already have Paperclip set up, but don&#39;t have a way to upload them programmatically in a rake task. Any ideas?

How to set a file upload programmatically using Paperclip

Here is `Bar#do_things`:

    class Bar   
      def do_things
        Foo.some_method(x) do |x|
          y = x.do_something
          return y_is_bad if y.bad? # how do i tell it to stop and return do_things? 
          y.do_something_else
        end
        keep_doing_more_things
      end
    end

And here is `Foo#some_method`: 

    class Foo
      def self.some_method(targets, &amp;block)
        targets.each do |target|
          begin
            r = yield(target)
          rescue 
            failed &lt;&lt; target
          end
        end
      end
    end

I thought about using raise, but I am trying to make it generic, so I don&#39;t want to put anything any specific in `Foo`.

How to break out from a ruby block?

I have a rails project running that defines the standard production:, :development and :test DB-connections in config/database.yml

In addition I have a quiz_development: and quiz_production: definition pointing to a differnet host/db/user/password

My goal now is to define a Migration that uses &quot;`quiz_#{RAILS_ENV`}`&quot; as its database configuration.

What I have tried (and failed):

- Setting ActiveRecord::Base.connection in the Migration file
- Changing the db:migrate task in rails to set ActiveRecord::Base.connection there

Question:

How can I make rake db:migrate use that other database definition?


Thanks,
Frank

Using Rails Migration on different database than standard &quot;production&quot; or &quot;development&quot;

I&#39;m running Ruby on Windows though I don&#39;t know if that should make a difference.  All I want to do is get the current working directory&#39;s absolute path.  Is this possible from irb?  Apparently from a script it&#39;s possible using `File.expand_path(__FILE__)`

But from irb I tried the following and got a &quot;Permission denied&quot; error:

    File.new(Dir.new(&quot;.&quot;).path).expand

how to get the current working directory&#39;s absolute path from irb

I am writing a Ruby script for use in the Rails environment, but I chose to run it from irb because reloading the Rails console can be a pain. Now the wait time is much shorter from irb, but I&#39;m bothered that I have to restart irb and require the script everytime I make a change. Is there a simpler way of reloading a script from irb? 

I found a method in [this thread][1], but that only applies to gem files apparently. My require statement looks like this

     require &quot;#{File.expand_path(__FILE__)}/../lib/query&quot;


EDIT: Having tried `load` rather than `require`, I still couldn&#39;t get it to work. I can&#39;t get a stop on these errors.

    ruby-1.9.2-p0 &gt; load &quot;#{File.expand_path(__FILE__)}/../lib/query.rb&quot;
    LoadError: no such file to load -- /Users/newuser/Dropbox/Sites/rails/hacknyc/(irb)/../lib/query.rb


  [1]: https://stackoverflow.com/questions/3463182/reload-rubygem-in-irb


How can I reload a script in IRB?

I was testing some DB entries in our production server in Rails Console where almost all the commands were producing a huge number of lines of output and causing the ssh channel to hang.

Is there a way to suppress the console/irb screenfuls?

How to suppress Rails console/irb outputs

I am starting out with Ruby on Rails. I am currently going through a tutorial where it says that I have to run a .rb file from IRB and that that will create a .xml file in my current directory.

My question is how do I run a .rb file  in IRB?  
And do I have to be in the directory where this .rb file lives when I run it in IRB?

I tried the following: just typing `irb` on the command line in the directory of the file. That starts an IRB session as far as I understand.  
Then I typed `irb &quot;filename.rb&quot;` which went through but didn&#39;t create anything in the current directory but at least it didn&#39;t give any errors.

I also tried a whole bunch of other stuff that plain gave me errors. So I don&#39;t think I can solve this myself and googling the matter didn&#39;t help at all.

I am running Leopard.

How to run a .rb file from IRB?

I am using IRB (interactive ruby console) to learn how to program with Ruby. How do I load a file into the console if I write my programs in a text editor first?



Ruby: How to load a file into interactive ruby console (IRB)?

Tab completion on IPython seems not to be working. For example,

    import numpy
    numpy.&lt;tab&gt;

simply adds a tab.

    import numpy
    num&lt;tab&gt;

just adds a tab, too. Could you please suggest some possible causes for this problem? I am running Windows 7 and Python 2.6.5.

`ipython` tab autocomplete does not work on imported module

I have a Bash tab-completion script for Apache&#39;s Hadoop.  Normally, I use zsh as my day-to-day shell.  It tends to be pretty bash-like when I need it to be, but it looks like the tab-completion systems are radically different between them.  Is there a simple way to &quot;convert&quot; the existing bash-tab-completion definitions to work in zsh?  I don&#39;t want to invest a ton of time in this, but if it&#39;s easy I&#39;d save a moderate amount of effort.

Can a Bash tab-completion script be used in zsh?

Let&#39;s say I have the following files in my current directory:

    buildBar.bat
    buildFoo.bat
    buildHouse.bat

And I type the following at my command prompt, `./bu` and then &lt;kbd&gt;TAB&lt;/kbd&gt;.

* In Bash, it gets expanded to `./build`

* In PowerShell, it gets expanded to `./buildBar.bat` -- the first item in the list.

* In Cmd, the behavior is the same as PowerShell.

I prefer the Bash behaviour - is there a way to make PowerShell behave like Bash?

How to make PowerShell tab completion work like Bash

How to get shell tab completion cooperating with `argparse` in a Python script?  

&lt;!-- language: lang-python --&gt;

    #!/usr/bin/env python
    import argparse
    
    def main(**args):
        pass
    
    if __name__ == &#39;__main__&#39;:
        parser = argparse.ArgumentParser()
        parser.add_argument(&#39;positional&#39;, choices=[&#39;spam&#39;, &#39;eggs&#39;])
        parser.add_argument(&#39;--optional&#39;, choices=[&#39;foo1&#39;, &#39;foo2&#39;, &#39;bar&#39;])
        args = parser.parse_args()
        main(**vars(args))

With an executable flag set on the .py file, the expected results should be something like:

&lt;!-- language: lang-bash --&gt;

    $ ./example.py sp&lt;tab&gt;             
       -&gt;  completes to &quot;./example.py spam&quot;
    $ ./example.py --op&lt;tab&gt; 
       -&gt;  completes to &quot;./example.py --optional&quot;
    $ ./example.py --optional b&lt;tab&gt;
       -&gt;  completes to &quot;./example.py --optional bar&quot;
    $ ./example.py --optional f&lt;tab&gt;   
       -&gt;  completes to &quot;./example.py --optional foo&quot;
           and, additionally, prints  &quot;foo1  foo2&quot;  choices on stdout on a new line



Custom tab completion in python argparse

TAB completion works fine in iPython terminal, but not in Firefox browser. 


So far I had tried but failed,

1). run a command `$ sudo easy_install readline`, 

then the .egg file was wrote in `/usr/local/lib/python2.7/dist-packages/readline-6.2.4.1-py2.7-linux-x86_64.egg,`

but TAB completion still doesn&#39;t work in Jupyter Notebook.


2). also tried to find locate the `ipython_notebook_config.py or  ipython_config.py`, but failed.


I use Python 3.5 and iPython 4.0.0.  and both are installed in Ubuntu 15.10  `/usr/share/anaconda3/bin/ipython`.

Any help would be appreciated!


Content Type	Original Author	Original Content on Stackoverflow
Question	John F. Miller	View Question on Stackoverflow
Solution 1 - Ruby	cldwalker	View Answer on Stackoverflow
Solution 2 - Ruby	John F. Miller	View Answer on Stackoverflow
Solution 3 - Ruby	Joseph	View Answer on Stackoverflow

How to enable auto completion in Ruby's IRB

Ruby Problem Overview

Ruby Solutions

Solution 1 - Ruby

Solution 2 - Ruby

Solution 3 - Ruby

Why can't DateTime.ParseExact() parse "9/1/2009" using "M/d/yyyy"

How to adjust the quality of a resized image in Python Imaging Library?

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