Columnize - Format an Array as a Column-aligned String

In showing a long lists, sometimes one would prefer to see the value arranged aligned in columns. Some examples include listing methods of an object, listing debugger commands, or showing a numeric array with data aligned.

Setup

$ irb
>> a = (1..10).to_a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>> require 'columnize'
=> true
>> include Columnize
=> Object
>> g = %w(bibrons golden madascar leopard mourning suras tokay)
=> ["bibrons", "golden", "madascar", "leopard", "mourning", "suras", "tokay"]

With numeric data

columnize(a) 
=> "1  2  3  4  5  6  7  8  9  10\n"
>> puts Columnize::columnize(a, :arrange_array => true, :displaywidth => 10)
[1,  2
 3,  4
 5,  6
 7,  8
 9, 10
]
=> nil
>> puts Columnize::columnize(a, :arrange_array => true, :displaywidth => 20)
[1, 2, 3,  4,  5,  6
 7, 8, 9, 10
]

With String data

>> puts columnize g, :displaywidth => 15
bibrons   suras
golden    tokay
madascar
leopard 
mourning
=> nil

>> puts columnize g, {:displaywidth => 19, :colsep => ' | '}
bibrons  | suras
golden   | tokay
madascar
leopard 
mourning
=> nil

>> puts columnize g, {:displaywidth => 18, :colsep => ' | ', :ljust=>false}

bibrons  | mourning
golden   | suras   
madascar | tokay   
leopard 

Credits

This is adapted from a method of the same name from Python's cmd module.

Other stuff

Author: Rocky Bernstein [email protected]

License: Copyright (c) 2011 Rocky Bernstein

Warranty

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.