Hash sanitization from query - newbie

[Sem Ptiri]

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.

 

[Josh Cheek]

[Note: parts of this message were removed to make it a legal post.]

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?

# http://ruby-doc.org/core/classes/Hash.html#M000747

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}]

 

[botp]

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

 

[Sem Ptiri]

Thanks for the comparisons.

 

[Sem Ptiri]

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?

 

[Estanislau Trepat]

[Note: parts of this message were removed to make it a legal post.]

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]]

 

[Robert Klemme]

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

 

[Jesús Gabriel y Galán]

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.