Hash sanitization from query - newbie

Ruby
1

I need to clean up a hash

[{0=>“BSD”, 1=>105, “Operating System”=>“BSD”, “count()"=>105},
{0=>“SUSE”, 1=>99, “Operating System”=>“SUSE”, "count()”=>99},
{0=>“Ubuntu”, 1=>97, “Operating System”=>“Ubuntu”, “count()"=>97},
{0=>“Unix”, 1=>190, “Operating System”=>“Unix”, "count()”=>190},
{0=>“Windows XP”, 1=>92, “Operating System”=>“Windows XP”,
“count(*)”=>92}]

You’ll notice the first part is an array key value pair and the second
part of each hash is a real key value pair.

How would I go about removing all the 0=> and 1=> references from the
above hash?

I’ve seen people use inject and map but are a bit lost with regards to
those functions.

2

On Tue, Feb 8, 2011 at 1:27 PM, Sem P. [email protected]
wrote:

part of each hash is a real key value pair.

How would I go about removing all the 0=> and 1=> references from the
above hash?

class Hash - RDoc Documentation

oses = [
{0=>“BSD”, 1=>105, “Operating System”=>“BSD”, “count()"=>105},
{0=>“SUSE”, 1=>99, “Operating System”=>“SUSE”, "count()”=>99},
{0=>“Ubuntu”, 1=>97, “Operating System”=>“Ubuntu”, “count()"=>97},
{0=>“Unix”, 1=>190, “Operating System”=>“Unix”, "count()”=>190},
{0=>“Windows XP”, 1=>92, “Operating System”=>“Windows
XP”,“count(*)”=>92}
]

oses.each do |os|
os.delete 0
os.delete 1
end

require ‘pp’
pp oses

>> [{“Operating System”=>“BSD”, “count(*)”=>105},

>> {“Operating System”=>“SUSE”, “count(*)”=>99},

>> {“Operating System”=>“Ubuntu”, “count(*)”=>97},

>> {“Operating System”=>“Unix”, “count(*)”=>190},

>> {“Operating System”=>“Windows XP”, “count(*)”=>92}]

3

On Wed, Feb 9, 2011 at 3:27 AM, Sem P. [email protected]
wrote:

I’ve seen people use inject and map but are a bit lost with regards to
those functions.

oses = [
{0=>“BSD”, 1=>105, “Operating System”=>“BSD”, “count()"=>105},
{0=>“SUSE”, 1=>99, “Operating System”=>“SUSE”, "count()”=>99},
{0=>“Ubuntu”, 1=>97, “Operating System”=>“Ubuntu”, “count()"=>97},
{0=>“Unix”, 1=>190, “Operating System”=>“Unix”, "count()”=>190},
{0=>“Windows XP”, 1=>92, “Operating System”=>“Windows
XP”,“count(*)”=>92}
]

map version

oses.map{|h| h.delete_if{|k,_| k==0 or k==1}}

#=> [{“Operating System”=>“BSD”, “count()"=>105}, {“Operating
System”=>“SUSE”, "count()”=>99}, {“Operating System”=>“Ubuntu”,
“count()"=>97}, {“Operating System”=>“Unix”, "count()”=>190},
{“Operating System”=>“Windows XP”, “count(*)”=>92}]

inject version

oses.inject([]){|a,h| a << h.delete_if{|k,_| k==0 or k==1} }
#=> [{“Operating System”=>“BSD”, “count()"=>105}, {“Operating
System”=>“SUSE”, "count()”=>99}, {“Operating System”=>“Ubuntu”,
“count()"=>97}, {“Operating System”=>“Unix”, "count()”=>190},
{“Operating System”=>“Windows XP”, “count(*)”=>92}]

but note, you have repeating keys wc could be just be fields themselves,
eg

oses.map{|h| h.delete_if{|k,_| k==0 or k==1}; h.values}
#=> [[“BSD”, 105], [“SUSE”, 99], [“Ubuntu”, 97], [“Unix”, 190],
[“Windows XP”, 92]]

or

Hash[ *oses.map{|h| h.delete_if{|k,_| k==0 or k==1}; h.values}.flatten ]
#=> {“BSD”=>105, “SUSE”=>99, “Ubuntu”=>97, “Unix”=>190, “Windows
XP”=>92}

best regards -botp

4

If I have the following:

[[148,“Uneducated”],[135,“Highschool”],[272,“Some
college”],[141,“University”],[143,“Post-grad”],[144,“PhD”],[141,“other”],[8,“Post-doc”]]

is there an function to invert/swap the numbers with strings?

5

Thanks for the comparisons.

6

Maybe I misunderstand what you are trying to do here, but what about
something like:

studies = [[148,“Uneducated”],[135,“Highschool”],[272,“Some
college”],[141,“University”],[143,“Post-grad”],[144,“PhD”],[141,“other”],[8,“Post-doc”]]

studies.map(&:reverse)
=> [[“Uneducated”, 148], [“Highschool”, 135], [“Some college”, 272],
[“University”, 141], [“Post-grad”, 143], [“PhD”, 144], [“other”, 141],
[“Post-doc”, 8]]

–
Estanislau Trepat

http://twitter.com/etrepat

2011/2/15 Sem P. [email protected]

7

On Tue, Feb 15, 2011 at 10:51 AM, Sem P. [email protected]
wrote:

If I have the following:

[[148,“Uneducated”],[135,“Highschool”],[272,"Some

college"],[141,“University”],[143,“Post-grad”],[144,“PhD”],[141,“other”],[8,“Post-doc”]]

is there an function to invert/swap the numbers with strings?

Take a look at map or map! (if you want to modify the object in place):

irb(main):005:0> a = [[148,“Uneducated”],[135,“Highschool”],[272,“Some
college”],[141,“University”],[143,“Post-grad”],[144,“PhD”],[141,“other”],[8,“Post-doc”]]
=> [[148, “Uneducated”], [135, “Highschool”], [272, “Some college”],
[141, “University”], [143, “Post-grad”], [144, “PhD”], [141, “other”],
[8, “Post-doc”]]
irb(main):006:0> a.map {|(num,string)| [string,num]}
=> [[“Uneducated”, 148], [“Highschool”, 135], [“Some college”, 272],
[“University”, 141], [“Post-grad”, 143], [“PhD”, 144], [“other”, 141],
[“Post-doc”, 8]]

Jesus.

8

On Tue, Feb 15, 2011 at 10:51 AM, Sem P. [email protected]
wrote:

If I have the following:

[[148,“Uneducated”],[135,“Highschool”],[272,"Some

college"],[141,“University”],[143,“Post-grad”],[144,“PhD”],[141,“other”],[8,“Post-doc”]]

is there an function to invert/swap the numbers with strings?

irb(main):001:0> [[148,“Uneducated”],[135,“Highschool”],[272,“Some
irb(main):002:2”
college"],[141,“University”],[143,“Post-grad”],[144,“PhD”],[141,“other”],[8,“Post-doc”]].each
{|a| a.reverse!}
=> [[“Uneducated”, 148], [“Highschool”, 135], [“Some\ncollege”, 272],
[“University”, 141], [“Post-grad”, 143], [“PhD”, 144], [“other”, 141],
[“Post-doc”, 8]]

Btw, for your original problem there is an elegant solution which has
not been shown yet:

irb(main):003:0> [{0=>“BSD”, 1=>105, “Operating System”=>“BSD”,
"count()"=>105},
irb(main):004:1 {0=>“SUSE”, 1=>99, “Operating System”=>“SUSE”,
"count()"=>99},
irb(main):005:1 {0=>“Ubuntu”, 1=>97, “Operating System”=>“Ubuntu”,
"count()"=>97},
irb(main):006:1 {0=>“Unix”, 1=>190, “Operating System”=>“Unix”,
"count()"=>190},
irb(main):007:1 {0=>“Windows XP”, 1=>92, “Operating System”=>“Windows
XP”,
irb(main):008:2* “count()"=>92}].each {|h| h.delete_if {|k,| Integer
=== k}}
=> [{“Operating System”=>“BSD”, "count()”=>105}, {“Operating
System”=>“SUSE”, “count()"=>99}, {“Operating System”=>“Ubuntu”,
"count()”=>97}, {“Operating System”=>“Unix”, “count()"=>190},
{“Operating System”=>“Windows XP”, "count()”=>92}]

Although you have to consider that this works only if you do not have
numeric keys that you want to keep.

Cheers

robert