[bundle init](https://bundler.io/man/bundle-init.1.html) generates a Gemfile into the current working directory.

&lt;!-- language: lang-sh --&gt;

    $ bundle init
    Writing new Gemfile to /app/Gemfile
    
    $ cat Gemfile 
    # frozen_string_literal: true
    
    source &quot;https://rubygems.org&quot;
    
    git_source(:github) {|repo_name| &quot;https://github.com/#{repo_name}&quot; }
    
    # gem &quot;rails&quot;


The Gemfile is just a text file within your project which contains a list of gems for use in your application.

If you do not have one in your application, you can create the file using an editor of your choice, saving it as `Gemfile` (with no extension), and in your example, containing:

```
source &#39;https://rubygems.org&#39;
    
gem &#39;rspec&#39;
```

A gemfile is automatically created when you start a new rails application.

type `rails new appName` and then it will be generated automatically. It will also be populated with some gems.

To install the gems run `bundle install` or simply `bundle`

Make sure you are requiring the gems you need. specifically `rspec` and `jruby`

    group :development, :test do
      gem &#39;rspec-rails&#39;, &#39;~&gt; 3.0&#39;
    end

Look at this website for more information

http://bundler.io/

Given is a simple CSV file:

    A,B,C
    Hello,Hi,0
    Hola,Bueno,1

Obviously the real dataset is far more complex than this, but this one reproduces the error. I&#39;m attempting to build a random forest classifier for it, like so:

    cols = [&#39;A&#39;,&#39;B&#39;,&#39;C&#39;]
    col_types = {&#39;A&#39;: str, &#39;B&#39;: str, &#39;C&#39;: int}
    test = pd.read_csv(&#39;test.csv&#39;, dtype=col_types)
    
    train_y = test[&#39;C&#39;] == 1
    train_x = test[cols]

    clf_rf = RandomForestClassifier(n_estimators=50)
    clf_rf.fit(train_x, train_y)

But I just get this traceback when invoking fit():

    ValueError: could not convert string to float: &#39;Bueno&#39;

scikit-learn version is 0.16.1.

RandomForestClassfier.fit(): ValueError: could not convert string to float

I am new to python, and i read some code snippet from some place. It&#39;s an implementation of counting sort.

The code is as below:

    from collections import defaultdict
    def sort_colors(A):
        ht = {}                        # a hash map
        ht = defaultdict(lambda:0, ht) # with default value 1
        for i in A:
             ht[i] += 1
        ret = []
        for k in [0, 1, 2]:
            ret.extend([k]*ht[k])
        return ret

As in the first two lines of the func, it&#39;s

    ht = {}
    ht = defaultdict(lambda:0, ht)

I am not quite clear about this initialization.Could you kindly help me figure it out? and also, Shall we just replace these two lines with following?

    ht = defaultdict(int) # default value 0

defaultdict with default value 1?

I&#39;m very new to Ruby.

I was following a blog post that says that in order to install a required dependencies I need to create a Gemfile.

How do I create a Gemfile with `rspec` as a dependency?

How to create a Gemfile?

I'm very new to Ruby.
I was following a blog post that says that in order to install a required dependencies I need to create a Gemfile.
How do I create a Gemfile with <code>rspec</code> as a dependency?

Just installed El Capitan and can&#39;t install gem `eventmachine` `1.0.7`. `openssl` is at `1.0.2a-1`. Tried to use `--with-ssl-dir` but it seems ignored.

Reported it to their [github repo](https://github.com/eventmachine/eventmachine/issues/602) as well.

Any suggestions are really appreciated. Thanks.

    $ ls /usr/local/Cellar/openssl/1.0.2a-1/include/openssl/ssl.h
    /usr/local/Cellar/openssl/1.0.2a-1/include/openssl/ssl.h
    
    $ gem install eventmachine -v &#39;1.0.7&#39; -- --with-ssl-dir=/usr/local/Cellar/openssl/1.0.2a-1/include
    /Users/pain/.rbenv/versions/2.1.2/bin/ruby -r ./siteconf20150612-56154-1hsjz2n.rb extconf.rb --with-ssl-dir=/usr/local/Cellar/openssl/1.0.2a-1/include
    checking for rb_trap_immediate in ruby.h,rubysig.h... no
    checking for rb_thread_blocking_region()... yes
    checking for ruby/thread.h... yes
    checking for rb_thread_call_without_gvl() in ruby/thread.h... yes
    checking for inotify_init() in sys/inotify.h... no
    checking for __NR_inotify_init in sys/syscall.h... no
    checking for writev() in sys/uio.h... yes
    checking for rb_thread_fd_select()... yes
    checking for rb_fdset_t in ruby/intern.h... yes
    checking for rb_wait_for_single_fd()... yes
    checking for rb_enable_interrupt()... no
    checking for rb_time_new()... yes
    checking for sys/event.h... yes
    checking for sys/queue... yes
    checking for clock_gettime()... no
    checking for gethrtime()... no
    creating Makefile
    
    make &quot;DESTDIR=&quot; clean
    
    make &quot;DESTDIR=&quot;
    compiling binder.cpp
    In file included from binder.cpp:20:
    ./project.h:116:10: fatal error: &#39;openssl/ssl.h&#39; file not found
    #include &lt;openssl/ssl.h&gt;
             ^
    1 error generated.
    make: *** [binder.o] Error 1
    
    make failed, exit code 2
    




gem eventmachine fatal error: &#39;openssl/ssl.h&#39; file not found

Im trying to install an open source rails 3.2.21 application that uses the `mysql2` gem, but when i try and run the `bundle` commant I get the following error:

    Fetching: mysql2-0.3.18.gem (100%)
    Building native extensions.  This could take a while...
    p
    ERROR:  Error installing mysql2:
    	ERROR: Failed to build gem native extension.
    
        /Users/my_username/.rvm/rubies/ruby-2.1.2/bin/ruby -r ./siteconf20150614-72129-orqsb7.rb extconf.rb
    checking for ruby/thread.h... yes
    checking for rb_thread_call_without_gvl() in ruby/thread.h... yes
    checking for rb_thread_blocking_region()... yes
    checking for rb_wait_for_single_fd()... yes
    checking for rb_hash_dup()... yes
    checking for rb_intern3()... yes
    -----
    Using mysql_config at /usr/local/bin/mysql_config
    -----
    checking for mysql.h... yes
    checking for errmsg.h... yes
    checking for mysqld_error.h... yes
    -----
    Don&#39;t know how to set rpath on your system, if MySQL libraries are not in path mysql2 may not load
    -----
    -----
    Setting libpath to /usr/local/Cellar/mysql/5.6.25/lib
    -----
    creating Makefile
    
    make &quot;DESTDIR=&quot; clean
    
    make &quot;DESTDIR=&quot;
    compiling client.c
    compiling infile.c
    compiling mysql2_ext.c
    compiling result.c
    linking shared-object mysql2/mysql2.bundle
    ld: warning: directory not found for option &#39;-L/Users/travis/.sm/pkg/active/lib&#39;
    ld: library not found for -lssl
    clang: error: linker command failed with exit code 1 (use -v to see invocation)
    make: *** [mysql2.bundle] Error 1
    
    make failed, exit code 2
    
    Gem files will remain installed in /Users/my_username/.rvm/rubies/ruby-2.1.2/lib/ruby/gems/2.1.0/gems/mysql2-0.3.18 for inspection.
    Results logged to /Users/my_username/.rvm/rubies/ruby-2.1.2/lib/ruby/gems/2.1.0/extensions/x86

I tried uninstalling every version of `mysql` I installed via homebrew and reinstalling them, like so:

    brew uninstall --force mysql &amp;&amp; brew install mysql

Then running:

    sudo gem install mysql2

As suggested by a number of similar questions asked on here, but it still results in the same error as above.

Please could someone offer guidance on how to get this up and running?

Error when trying to install app with mysql2 gem

In my Rails app, I use `Rubocop` to check for problems. Today it gave me an error like this : `Assignment Branch Condition size for show is too high`. Here&#39;s my code :

    def show
      @category = Category.friendly.find(params[:id])
      @categories = Category.all
      @search = @category.products.approved.order(updated_at: :desc).ransack(params[:q])
      @products = @search.result.page(params[:page]).per(50)
      rate
    end

What does this mean and how can I fix it?

What is meant by &#39;Assignment Branch Condition Size too high&#39; and how to fix it?

How do you uninstall rbenv on macOS? My version of rbenv is messed up, and `brew uninstall rbenv` isn&#39;t working because brew relies on&#160;ruby.

How do you uninstall rbenv on macOS?

There are many themes for Jekyll, e.g. https://github.com/jekyll/jekyll/wiki/Themes.

What is the easiest way to switch to a new theme in an EXISTING Jekyll installation?



Switch theme in an existing Jekyll installation

After upgrading a Rails app to Rails 5, running RSpec tests gives me the following error:

    rails aborted!
    ActiveRecord::NoEnvironmentInSchemaError: 

    Environment data not found in the schema. To resolve this issue, run: 

	    bin/rails db:environment:set RAILS_ENV=test

However, that `bin` does not exist and I can&#39;t seem to generate it with `bundle binstubs rails` or with `rake rails:update:bin`.

I have also tried:
    
    rails db:environment:set RAILS_ENV=test
    rake db:environment:set RAILS_ENV=test

There is a related issue on Github [here](https://github.com/rails/rails/issues/23279).

How can I address this error?

Rails 5, Rspec: Environment data not found in the schema

http://betterspecs.org/#subject has some info about `subject` and `let`. However, I am still unclear on the difference between them. Furthermore, the SO post https://stackoverflow.com/questions/12869026/what-is-the-argument-against-using-before-let-and-subject-in-rspec-tests said it is better to not use either `subject` or `let`. Where shall I go? I am so confused.

What&#39;s the difference between RSpec&#39;s subject and let? When should they be used or not?

What is the purpose of `transient do` in FactoryBot factories?

I&#39;ve seen a lot of factories that begin with something like below. 

    factory :car do
      owner nil
      other_attribute nil
    end
    ...

I&#39;ve found some information on this blog:  
[Using FactoryGirl to easily create complex data sets in Rails](https://web.archive.org/web/20180403000920/http://blog.thefrontiergroup.com.au/2014/12/using-factorygirl-easily-create-complex-data-sets-rails/)

But I still don&#39;t fully understand how and why to do this. My experience with FactoryBot is minimal.

Could anyone with some experience using FactoryBot share some insight?

What is the purpose of a `transient do` block in FactoryBot factories?

A typical RSpec unit test makes extensive use of nested Ruby blocks in order to structure the code and make use of DSL &quot;magic&quot; to have specs read like BDD statements:

    describe Foo do
      context &quot;with a bar&quot; do
        before :each do
          subject { Foo.new().add_bar }
        end
          
        it &quot;looks like a baz&quot; do
          expect # etc
    
In an ideal spec, each example can be relatively short and precise. However it seems usual to have outer blocks grow to 100 lines plus, because the RSpec structure works this way, and doesn&#39;t take many spec examples, each of which might have a few lines of specific setup, to get to `describe` blocks that are the same size or larger than the code for the subject being described.

A recent upgrade of Rubocop brought a new rule into play, that blocks should be no longer than 25 lines. I&#39;m not sure of the rationale for it, because it is not listed in the [Ruby style guide][1]. I can see why it could be a good thing, and added to default ruleset. However, after the upgrade, our Rubocop test fails multiple times with messages like `tests/component_spec.rb:151:3: C: Block has too many lines. [68/25]`

With code metric tools such as Rubocop, I *like* to have a policy of &quot;Use the defaults, link to the style guide, job done.&quot; (mainly because debating tabs vs spaces and other minutiae is wasting time, and IME *never* gets resolved) Here that is clearly not possible, two of our core data quality tools disagree about code layout approach - or at least that is how I interpret the results, I don&#39;t see anything intrinsically wrong with how we&#39;ve written the specs. 

In response, we have simply set the Rubocop block size rule to a high threshold. But that makes me wonder - what am I missing? Is RSpec using a now discredited approach for code layout, and what *reasonable* options do I have to reduce block sizes in our RSpec tests? I can see ways to restructure the code to avoid large blocks, but they are without exception ugly hacks intended purely to meet Rubocop&#39;s rule e.g. break out all the blocks into helper functions:

    def looks_like_a_baz
      it &quot;looks like a baz&quot; do
             expect # etc
      end
    end

    def bar_context
      context &quot;with a bar&quot; do
        before :each do
          subject { Foo.new().add_bar }
        end
        looks_like_a_baz
      end
    end

    
    describe Foo do
      bar_context
      # etc

 . . . I mean, that&#39;s do-able, but turning bunches of spec examples into helper functions in this way seems to be the opposite of the readable approach encouraged by RSpec design.

Is there anything else I can do other than find ways to ignore it?

----

The closest existing question I could find about this topic here was https://stackoverflow.com/questions/25138264/rspec-rubocop-ruby-style-guide and this looked solvable by editing test templates.

  [1]: https://github.com/bbatsov/ruby-style-guide#source-code-layout

Rubocop 25 line block size and RSpec tests

I have simple action show 

    def show
      @field = Field.find_by(params[:id])
    end

and i want write spec for it 

    require &#39;spec_helper&#39;
    
    RSpec.describe FieldsController, type: :controller do
    
        let(:field) { create(:field) }
    
      it &#39;should show field&#39; do
        get :show, id: field
        expect(response.status).to eq(200)
      end
    end


but I have got an error

    Failure/Error: get :show, id: field
     
     ArgumentError:
       unknown keyword: id

How to fix it?

Content Type	Original Author	Original Content on Stackoverflow
Question	Saurabh Juneja	View Question on Stackoverflow
Solution 1 - Ruby	Andy Waite	View Answer on Stackoverflow
Solution 2 - Ruby	CDub	View Answer on Stackoverflow
Solution 3 - Ruby	Richard Hamilton	View Answer on Stackoverflow

How to create a Gemfile?

Ruby Problem Overview

Ruby Solutions

Solution 1 - Ruby

Solution 2 - Ruby

Solution 3 - Ruby

defaultdict with default value 1?

RandomForestClassfier.fit(): ValueError: could not convert string to float

Attributions