I would use [`ruby-build`](https://github.com/rbenv/ruby-build#usage) with `rbenv`. The following lines install Ruby 3.1.2 and set it as your default Ruby version:

    $ brew update
    $ brew install ruby-build
    $ brew install rbenv

    $ rbenv install 3.1.2
    $ rbenv global 3.1.2

`brew upgrade ruby`

Should pull latest version of the package and install it.

`brew update` updates brew itself, not packages _(formulas they call it)_

To upgrade Ruby with rbenv:  Per the [rbenv README](https://github.com/rbenv/rbenv#upgrading-with-homebrew)

 - Update first: `brew upgrade rbenv ruby-build`
 - See list of Ruby versions: versions available: `rbenv install -l` 
 - Install: `rbenv install &lt;selected version&gt;`

Adding to the selected answer (as I haven&#39;t enough rep to add comment), one way to see the list of available versions ([from ref][1]) try: 

    $ rbenv install -l

[1]: https://github.com/rbenv/rbenv#installing-ruby-versions


open terminal

`\curl -sSL https://get.rvm.io | bash -s stable`

restart terminal then 

    rvm install ruby-2.4.2

check ruby version it should be  2.4.2

I have a pandas dataframe &quot;df&quot;. In this dataframe I have multiple columns, one of which I have to substring.
Lets say the column name is &quot;col&quot;.
I can run a &quot;for&quot; loop like below and substring the column:
    
    for i in range(0,len(df)):
      df.iloc[i].col = df.iloc[i].col[:9]

But I wanted to know, if there is an option where I don&#39;t have to use a &quot;for&quot; loop, and do it directly using an attribute.I have huge amount of data, and if I do this, the data will take a very long time process.
      


substring of an entire column in pandas dataframe

I&#39;m trying to get enum type from raw value:

    enum TestEnum: String {
    	case Name
    	case Gender
    	case Birth
    	
    	var rawValue: String {
    		switch self {
    		case .Name: return &quot;Name&quot;
    		case .Gender: return &quot;Gender&quot;
    		case .Birth: return &quot;Birth Day&quot;
    		}
    	}
    }
    
    let name = TestEnum(rawValue: &quot;Name&quot;)       //Name
    let gender = TestEnum(rawValue: &quot;Gender&quot;)   //Gender

But it seems that `rawValue` doesn&#39;t work for string with spaces:

    let birth = TestEnum(rawValue: &quot;Birth Day&quot;) //nil

Any suggestions how to get it?

How to get enum from raw value in Swift?

I want to know how to update to the latest **stable** version of Ruby with Homebrew. I am **not** interested in using RVM. Thanks.

How to update Ruby with Homebrew?

I want to know how to update to the latest stable version of Ruby with Homebrew. I am not interested in using RVM. Thanks.

I came across this line of ruby code. What does `&amp;.` mean in this?

    @object&amp;.method

What does &amp;. (ampersand dot) mean in Ruby?

My project is extending open-source classes from a third-party gem that we don&#39;t want to hold to the same coding standards as our own code.  Refactoring the gem code isn&#39;t a viable option.  We just want Rubocop to ignore the copied code.

How can I instruct Rubocop to completely ignore a file or directory?

How to tell Rubocop to ignore a specific directory or file

I just added RuboCop to a rails project and installed the Sublime package to see RuboCop suggestions in the editor. I&#39;m trying to figure out how to change the maximum line length from 80 characters, or just ignore the rule completely. 

Currently in use:

 - [RuboCop (gem)][1]
 - [Sublime RuboCop][2] 
 - [SublimeLinter-rubocop][3]


  [1]: https://github.com/bbatsov/rubocop
  [2]: https://github.com/pderichs/sublime_rubocop
  [3]: https://github.com/SublimeLinter/SublimeLinter-rubocop

RuboCop: Line is too long ← How to Ignore?

Before anything, please note that I have found several similar questions on Stack Overflow and articles all over the web, but none of those helped me fix my issue:

 - https://stackoverflow.com/questions/24333317/pg-error-could-not-connect-to-server-connection-refused-is-the-server-running-o
 - https://stackoverflow.com/questions/19828385/pgconnectionbad-could-not-connect-to-server-connection-refused
 - [psql: could not connect to server: Connection refused][1]

Now, here is the issue:

 - I have a Rails app that works like a charm.
 - With my collaborator, we use GitHub to work together.
 - We have a `master` and an `mvp` branches.
 - I recently updated my `git` version with Homebrew (Mac).
 - We use Foreman to start our app locally.

Now, when I try to launch the app locally, I get the following error:

    PG::ConnectionBad at /
    could not connect to server: Connection refused
    	Is the server running on host &quot;localhost&quot; (::1) and accepting
    	TCP/IP connections on port 5432?
    could not connect to server: Connection refused
    	Is the server running on host &quot;localhost&quot; (127.0.0.1) and accepting
    	TCP/IP connections on port 5432?

I tried to reboot my computers several times.

I also checked the content of `/usr/local/var/postgres`:

    PG_VERSION		pg_dynshmem		pg_multixact	pg_snapshots	pg_tblspc		postgresql.conf
    base			pg_hba.conf		pg_notify		pg_stat			pg_twophase		postmaster.opts
    global			pg_ident.conf	pg_replslot		pg_stat_tmp		pg_xlog			server.log
    pg_clog			pg_logical		pg_serial		pg_subtrans		postgresql.auto.conf

As you can see, there is no `postmaster.pid` file in there.

Any idea how I could fix this?

  [1]: https://github.com/PostgresApp/PostgresApp/issues/37

Is the server running on host &quot;localhost&quot; (::1) and accepting TCP/IP connections on port 5432?

This is the `rspec` binstub in my project directory.

    #!/usr/bin/env ruby
    begin
      load File.expand_path(&quot;../spring&quot;, __FILE__)
    rescue LoadError
    end
    # frozen_string_literal: true
    #
    # This file was generated by Bundler.
    #
    # The application &#39;rspec&#39; is installed as part of a gem, and
    # this file is here to facilitate running it.
    #
    
    require &quot;pathname&quot;
    ENV[&quot;BUNDLE_GEMFILE&quot;] ||= File.expand_path(&quot;../../Gemfile&quot;,
      Pathname.new(__FILE__).realpath)
    
    require &quot;rubygems&quot;
    require &quot;bundler/setup&quot;
    
    load Gem.bin_path(&quot;rspec-core&quot;, &quot;rspec&quot;)

What is this intended to do?

    # frozen_string_literal: true

Ruby: What does the comment &quot;frozen_string_literal: true&quot; do?

    ➜  ~ /usr/bin/ruby -e &quot;$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)&quot;
    -e:77: warning: Insecure world writable dir /usr/local/bin in PATH, mode 040677
    It appears Homebrew is already installed. If your intent is to reinstall you
    should do the following before running this installer again:
        ruby -e &quot;$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)&quot;
    The current contents of /usr/local are bin CODEOFCONDUCT.md etc git lib Library LICENSE.txt munki README.md sbin share .git .github .gitignore
    ➜  ~ brew install maven
    zsh: command not found: brew

After installing Homebrew I get `zsh: command not found: brew`

When I try to symlink a binary in my /usr/bin folder, I get an Operation not permitted error:

     sudo ln -s /usr/bin/python2.7 /usr/bin/python2
    ln: /usr/bin/python2: Operation not permitted

Even as sudo, I get this error.

Cannot create a symlink inside of /usr/bin even as sudo

I&#39;ve installed Python via Homebrew on my Mac.

    brew install python

After that I checked my Python version as 2.7.11, then I tried to perform

    import Tkinter

I got following error message:

    Traceback (most recent call last):
      File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
      File &quot;/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk/Tkinter.py&quot;, line 39, in &lt;module&gt;
        import _tkinter # If this fails your Python may not be configured for Tk
    ImportError: No module named _tkinter


Why does Python installed via Homebrew not include Tkinter

Trying to commit my changes by using GitHub Desktop and getting this:

[![enter image description here][1]][1]

&gt;error: cannot run gpg: No such file or directory
&gt;
&gt;error: could not run gpg.
&gt;
&gt;fatal: failed to write commit object
 (128)

Firstly that not worked for terminal too and i create gpg-key and plugged in to my GitHub Account
Now it&#39;s  working well in Terminal but Desktop version still not working.


&gt;In Oficial doccumentation for GitHub Desktop i found some notation:
&gt;
&gt;Note: GitHub Desktop does not support GPG signing.

  [1]: http://i.stack.imgur.com/yYem2.png

Git Hub Desktop on Mac, error: cannot run gpg: No such file or directory

I&#39;m attempting to install `jekyll` and I&#39;ve encountered an error. I&#39;m running Mac OS X 10.11.4 (El Capitan).

    $gem install jekyll
    ERROR : While executing gem ... (Gem::Exception)
            Unable to require openssl, install OpenSSL and rebuild ruby (preferred) or use non-HTTPS sources
    $gem source -l
    https://ruby.taobao.org
    $which openssl
    /usr/local/bin/openssl

I welcome your suggestions how to resolve this error.

Unable to require openssl, install OpenSSL and rebuild ruby (preferred) or use non-HTTPS sources

I am learning JSP programing which requires Tomcat. I followed [some tutorials][1] but failed to install successfully(Probably some step is not clear match to my situation)


Then I found out you can install easily by this command line:


    brew install tomcat


It looks install is successful, 

[![enter image description here][2]][2]


My challenge is after install, I don&#39;t know where it is on my hard drive. Therefore, can&#39;t configure it in IntelliJ. 

[![enter image description here][3]][3]


My question is:

How do I find out where Tomcat is installed by brew on MacOS? 


Thanks!

  [1]: https://wolfpaulus.com/journal/mac/tomcat8/
  [2]: http://i.stack.imgur.com/7lpyx.png
  [3]: http://i.stack.imgur.com/BBa2z.png

How to find out which folder Tomcat is installed by brew on MacOS?

Running `brew update` I get the following:

    /usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
    /usr/local/Library/brew.sh: line 32: /usr/local/Library/ENV/scm/git: No such file or directory
    [etc..]
    Error: update-report should not be called directly!

Calling `brew config` reports the following:


    HOMEBREW_VERSION: 0.9.9
    ORIGIN: https://github.com/Homebrew/brew.git
    HEAD: 90e84453f9adda65de6b9274987d06e46caa5d37
    Last commit: 4 hours ago
    Core tap ORIGIN: https://github.com/Homebrew/homebrew-core
    Core tap HEAD: 05ce2548bad01807c6be2aece21ab70d221755e6
    Core tap last commit: 8 weeks ago
    HOMEBREW_PREFIX: /usr/local
    HOMEBREW_REPOSITORY: /usr/local
    HOMEBREW_CELLAR: /usr/local/Cellar
    HOMEBREW_BOTTLE_DOMAIN: https://homebrew.bintray.com
    CPU: quad-core 64-bit ivybridge
    Homebrew Ruby: 2.0.0-p648
    Clang: 7.3 build 703
    Git: 2.7.0 =&gt; /usr/local/bin/git
    Perl: /usr/bin/perl
    Python: /Users/username/anaconda/bin/python =&gt; /Users/username/anaconda/bin/python2.7
    Ruby: /usr/bin/ruby =&gt; /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby
    Java: 1.7.0_79, 1.6.0_65-b14-468
    OS X: 10.11.4-x86_64
    Xcode: 7.3
    CLT: 7.3.0.0.1.1457485338
    X11: 2.7.8 =&gt; /opt/X11

Any idea how to fix this?  I wonder if Sophos Antivirus might be causing problems again..

Homebrew: Error: update-report should not be called directly

I&#39;m on: OSX 10.11.6, Homebrew version 0.9.9m OpenSSL 0.9.8zg 14 July 2015

I&#39;m trying to play with with dotnetcore and by following their [instructions][1], 

I&#39;ve upgraded/installed the latest version of openssl:

    &gt; brew install openssl
    ==&gt; Downloading https://homebrew.bintray.com/bottles/openssl-1.0.2h_1.el_capitan.bottle.tar.gz
    Already downloaded: /Users/administrator/Library/Caches/Homebrew/openssl-1.0.2h_1.el_capitan.bottle.tar.gz
    ==&gt; Pouring openssl-1.0.2h_1.el_capitan.bottle.tar.gz
    ==&gt; Caveats
    A CA file has been bootstrapped using certificates from the system
    keychain. To add additional certificates, place .pem files in
      /usr/local/etc/openssl/certs
    
    and run
      /usr/local/opt/openssl/bin/c_rehash
    
    This formula is keg-only, which means it was not symlinked into /usr/local.
    
    Apple has deprecated use of OpenSSL in favor of its own TLS and crypto libraries
    
    Generally there are no consequences of this for you. If you build your
    own software and it requires this formula, you&#39;ll need to add to your
    build variables:
    
        LDFLAGS:  -L/usr/local/opt/openssl/lib
        CPPFLAGS: -I/usr/local/opt/openssl/include


But when I try to link openssl I continue to run into this linking error:

    &gt; brew link --force openssl
    Warning: Refusing to link: openssl
    Linking keg-only OpenSSL means you may end up linking against the insecure,
    deprecated system version while using the headers from the Homebrew version.
    Instead, pass the full include/library paths to your compiler e.g.:
      -I/usr/local/opt/openssl/include -L/usr/local/opt/openssl/lib

The option to include compiler flags doesn&#39;t make sense to me, since I&#39;m not compiling these libraries that I&#39;m dependent on. 

  [1]: https://www.microsoft.com/net/core#macos

**EDIT** dotnetcore has updated their instructions:

    brew update    
    brew install openssl    
    ln -s /usr/local/opt/openssl/lib/libcrypto.1.0.0.dylib /usr/local/lib/    
    ln -s /usr/local/opt/openssl/lib/libssl.1.0.0.dylib /usr/local/lib/


Homebrew refusing to link OpenSSL

Is there a way to obtain a list (possibly with descriptions) of all the casks installable with [Homebrew Cask][1]?

  [1]: https://github.com/Homebrew/homebrew-cask

Content Type	Original Author	Original Content on Stackoverflow
Question	Ralph David Abernathy	View Question on Stackoverflow
Solution 1 - Ruby	spickermann	View Answer on Stackoverflow
Solution 2 - Ruby	Gustavo Rubio	View Answer on Stackoverflow
Solution 3 - Ruby	ltrainpr	View Answer on Stackoverflow
Solution 4 - Ruby	ovisirius	View Answer on Stackoverflow
Solution 5 - Ruby	Devesh	View Answer on Stackoverflow

How to update Ruby with Homebrew?

Ruby Problem Overview

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How to get enum from raw value in Swift?

substring of an entire column in pandas dataframe

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