I'm having some trouble iterating through a series of nested hashes, and I think its because the inner hashes are named with strings. Unfortunately, I cannot simply change these names. Here is a generic hash of the kind that I am working with:
hash =
"name" => {
"stuff" => "value",
"key" => "value", },
"name" => {
"stuff" => "value",
"key" => "value", },
I'm trying to write a program that will print the fields labelled as "name" as well the values, within, when called by the names of their keys. Right now, I am stuck with
hash.each do |key, value|
puts key
key.each do |stuff, info|
puts info if category == "stuff"
end
end
but this gives the error that each is not a recognized method for the key, which is, I think, because the computer is treating it as a string due to its naming. Does anyone have any ideas how I can proceed from here (without changing the names of the keys)?
As #meager says - the sub-hash is in the value. Try this
hash.each do |key, sub_hash|
puts key
sub_hash.each do |category, info|
puts info if category == "stuff"
end
end
What you have is an array of hashes, and not a Hash:
arr = [
{"name" => {"stuff" => "value","key" => "value" }},
{"name" => {"stuff" => "value","key" => "value" }},
{"noname" => {}}
]
arr.each do |hash|
name = hash["name"]
puts name["stuff"] if name
end
Related
I want to compare two XML files where one is input and the other is output. I am converting both into a hash.
My idea is to get all the keys from the input XML converted to hash, and search each key in both the input and output hashes for their respective key/value pairs.
I have a hash:
{
"requisition_header" => {
"requested_by" => {"login" => "coupasupport"},
"department" => {"name" => "Marketing"},
"ship_to_address" => {"name" => "Address_1431693296"},
"justification" => nil,
"attachments" => [],
"requisition_lines" => [
{
"description" => "Cleaning Services for Building A",
"line_num" => 1,
"need_by_date" => 2010-09-23 07:00:00 UTC,
"source_part_num" => nil,
"supp_aux_part_num" => nil,
"unit_price" => #<BigDecimal:a60520c,'0.3E4',9(18)>,
"supplier" => {"name" => "amazon.com"},
"account" => {
"code" => "SF-Marketing-Indirect",
"account_type" => {"name" => "Ace Corporate"}
},
"currency" => {"code" => "USD"},
"payment_term" => {"code" => "Net 30"},
"shipping_term" => {"code" => "Standard"},
"commodity" => {"name" => "Marketing-Services"}
}
]
}
}
It is nested and all the values are not directly accessible.
I want a way to generate direct access to each value in the hash.
For example:
requisition_header.requested_by.login
will access "coupasupport".
requisition_header.department.name
will access "Marketing".
requisition_header.requisition_lines[0].description
will access "Cleaning Services for Building A".
requisition_header.requisition_lines[0].line_num
will access "1".
requisition_header.requisition_lines[0].need_by_date
will access "2010-09-23 07:00:00 UTC".
Each key built can be used to search for the value directly inside the hash.
That could be done with the following method, that translates the nested hash into nested OpenStructs:
require 'ostruct'
def deep_structify(hash)
result = {}
hash.each do |key, value|
result[key] = value.is_a?(Hash) ? deep_structify(value) : value
end if hash
OpenStruct.new(result)
end
hash = {"requisition_header"=>{"requested_by"=>{"login"=>"coupasupport"}, "department"=>{"name"=>"Marketing"}, "ship_to_address"=>{"name"=>"Address_1431693296"}, "justification"=>nil, "attachments"=>[], "requisition_lines"=>[{"description"=>"Cleaning Services for Building A", "line_num"=>1, "need_by_date"=>2010-09-23 07:00:00 UTC, "source_part_num"=>nil, "supp_aux_part_num"=>nil, "unit_price"=>#<BigDecimal:a60520c,'0.3E4',9(18)>, "supplier"=>{"name"=>"amazon.com"}, "account"=>{"code"=>"SF-Marketing-Indirect", "account_type"=>{"name"=>"Ace Corporate"}}, "currency"=>{"code"=>"USD"}, "payment_term"=>{"code"=>"Net 30"}, "shipping_term"=>{"code"=>"Standard"}, "commodity"=>{"name"=>"Marketing-Services"}}]}}
struct = deep_structify(hash)
struct.requisition_header.department.name
#=> "Marketing"
You can do it by overriding OpenStruct#new as well,
require 'ostruct'
class DeepStruct < OpenStruct
def initialize(hash=nil)
#table = {}
#hash_table = {}
if hash
hash.each do |k,v|
#table[k.to_sym] = (v.is_a?(Hash) ? self.class.new(v) : v)
#hash_table[k.to_sym] = v
new_ostruct_member(k)
end
end
end
def to_h
#hash_table
end
end
Now you can do:
require 'deep_struct'
hash = {"requisition_header"=>{"requested_by"=>{"login"=>"coupasupport"}, "department"=>{"name"=>"Marketing"}, "ship_to_address"=>{"name"=>"Address_1431693296"}, "justification"=>nil, "attachments"=>[], "requisition_lines"=>[{"description"=>"Cleaning Services for Building A", "line_num"=>1, "need_by_date"=>2010-09-23 07:00:00 UTC, "source_part_num"=>nil, "supp_aux_part_num"=>nil, "unit_price"=>#<BigDecimal:a60520c,'0.3E4',9(18)>, "supplier"=>{"name"=>"amazon.com"}, "account"=>{"code"=>"SF-Marketing-Indirect", "account_type"=>{"name"=>"Ace Corporate"}}, "currency"=>{"code"=>"USD"}, "payment_term"=>{"code"=>"Net 30"}, "shipping_term"=>{"code"=>"Standard"}, "commodity"=>{"name"=>"Marketing-Services"}}]}}
mystruct = DeepStruct.new hash
mystruct.requisition_header.requested_by.login # => coupasupport
mystruct.requisition_header.to_h # => {"requested_by"=>{"login"=>"coupasupport"}
You could use BasicObject#method_missing:
Code
class Hash
def method_missing(key,*args)
(args.empty? && key?(key)) ? self[key] : super
end
end
Example
hash = { animals: {
pets: { dog: "Diva", cat: "Boots", python: "Stretch" },
farm: { pig: "Porky", chicken: "Little", sheep: "Baa" }
},
finishes: {
tinted: { stain: "Millers", paint: "Oxford" },
clear: { lacquer: "Target", varnish: "Topcoat" }
}
}
hash.finishes.tinted.stain
#=> "Millers
hash.animals.pets.cat
#=> "Boots"
hash.animals.pets
#=> {:dog=>"Diva", :cat=>"Boots", :python=>"Stretch"}
hash.animals
#=> {:pets=>{:dog=>"Diva", :cat=>"Boots", :python=>"Stretch"},
# :farm=>{:pig=>"Porky", :chicken=>"Little", :sheep=>"Baa"}}
Reader challenge
There is a potential "gotcha" with this approach. I leave it to the reader to identify it. My example contains a clue. (Mind you, there may be other problems I haven't thought of.)
I am trying to create a nested hash from an array that has several elements saved to it. I've tried experimenting with each_with_object, each_with_index, each and map.
class Person
attr_reader :name, :city, :state, :zip, :hobby
def initialize(name, hobby, city, state, zip)
#name = name
#hobby = hobby
#city = city
#state = state
#zip = zip
end
end
steve = Person.new("Steve", "basketball","Dallas", "Texas", 75444)
chris = Person.new("Chris", "piano","Phoenix", "Arizona", 75218)
larry = Person.new("Larry", "hunting","Austin", "Texas", 78735)
adam = Person.new("Adam", "swimming","Waco", "Texas", 76715)
people = [steve, chris, larry, adam]
people_array = people.map do |person|
person = person.name, person.hobby, person.city, person.state, person.zip
end
Now I just need to turn it into a hash. One issue I am having is, when I'm experimenting with other methods, I can turn it into a hash, but the array is still inside the hash. The expected output is just a nested hash with no arrays inside of it.
# Expected output ... create the following hash from the peeps array:
#
# people_hash = {
# "Steve" => {
# "hobby" => "golf",
# "address" => {
# "city" => "Dallas",
# "state" => "Texas",
# "zip" => 75444
# }
# # etc, etc
Any hints on making sure the hash is a nested hash with no arrays?
This works:
person_hash = Hash[peeps_array.map do |user|
[user[0], Hash['hobby', user[1], 'address', Hash['city', user[2], 'state', user[3], 'zip', user[4]]]]
end]
Basically just use the ruby Hash [] method to convert each of the sub-arrays into an hash
Why not just pass people?
people.each_with_object({}) do |instance, h|
h[instance.name] = { "hobby" => instance.hobby,
"address" => { "city" => instance.city,
"state" => instance.state,
"zip" => instance.zip } }
end
Given a table ZipCodeInfos with fields zipcode, state, city (all strings), where zipcode is unique:
zipcode,city,state
"10000", "Fooville", "AA"
"10001", "Smallville", "AA"
"10002", "Whoville", "BB"
What is the fastest way to generate a hash object of the entire table where the zipcode is a key like this:
{ "10000" => {:city => "Fooville", :state => "AA" },
"10001" => {:city => "Smallville", :state => "AA" },
"10002" => {:city => "Whoville", :state => "BB" } }
I know for a given record I can use .attributes to generate a hash with key,value pairs of field-names, field-values, for example Zipcode.first.attributes gives me
{"id" => 1, "zipcode" => "10000", "city" => "Fooville", "state => "AA" }
But, short of brute force iterating over each record (via .map), I cannot quite figure out how to create the desired hash with the zipcode as the key for each node of the hash.
This is the best I could come up with, and I suspect there is some nifty Ruby goodness that is faster?
zip_info_hash = {}
ZipCodeInfo.all.map{|x| zip_info_hash[x.zip] =
{'state' => x.state, 'city' => x.city }}
You could also try:
ZipCodeInfos.all.group_by &:zipcode
will get you a hash of zip code to array of ZipCodeInfos activerecords.
You can use inject method.
Here is what I generally use.
def visitors_name_email
visitors.inject({}) do |result, visitor|
result.merge(visitor.name => visitor.email)
end
end
I can't think of a way to avoid map here. I'd make only some minor changes to your code:
zip_info=Hash[*ZipCodeInfo.all
.map{|x| [x.zip, {:city => x.city, :state => x.state}]}
.flatten]
I'm writing an API parser at the moment, and I'm working on formatting the data nicely.
So far, I have the following code:
data.each {|season| episodes[season["no"].to_i] = season["episode"].group_by{|i| i["seasonnum"].to_i}}
However, the only issue with this is that the output comes out like this:
8 => {
1 => [
[0] {
"epnum" => "150",
"seasonnum" => "01",
"prodnum" => "3X7802",
"airdate" => "2012-10-03",
"link" => "http://www.tvrage.com/Supernatural/episodes/1065195189",
"title" => "We Need to Talk About Kevin"
}
],
2 => [
[0] {
"epnum" => "151",
"seasonnum" => "02",
"prodnum" => "3X7803",
"airdate" => "2012-10-10",
"link" => "http://www.tvrage.com/Supernatural/episodes/1065217045",
"title" => "What's Up, Tiger Mommy?"
}
]
}
So there's a redundant array in each value of the secondary hash. How would I remove this array and just have the inside hash? So, for example I want:
8 => {
1 => {
"epnum" => "150",
"seasonnum" => "01",
"prodnum" => "3X7802",
"airdate" => "2012-10-03",
"link" => "http://www.tvrage.com/Supernatural/episodes/1065195189",
"title" => "We Need to Talk About Kevin"
}
,
etc.
EDIT: Here's the full file:
require 'httparty'
require 'awesome_print'
require 'debugger'
require 'active_support'
episodes = Hash.new{ [] }
response = HTTParty.get('http://services.tvrage.com/feeds/episode_list.php?sid=5410')
data = response.parsed_response['Show']['Episodelist']["Season"]
data.each { |season|
episodes[season["no"].to_i] = season["episode"].group_by{ |i|
i["seasonnum"].to_i
}
}
ap episodes
Input data: http://services.tvrage.com/feeds/episode_list.php?sid=5410
Wild guess:
data.each { |season|
episodes[season["no"].to_i] = season["episode"].group_by{ |i|
i["seasonnum"].to_i
}.first
}
It looks like you're using group_by (array of entries with same key) when you really want index_by (one entry per key).
data.each {|season| episodes[season["no"].to_i] = season["episode"].index_by {|i| i["seasonnum"].to_i}}
NOTE: If you can have MORE than one episode with the same seasonnum, you SHOULD use group by and have an array of values here. If you're just building a hash of episodes with a convenient lookup (one to one mapping), then index_by is what you want.
I have a set of data that is an array of hashes, with each hash representing one record of data:
data = [
{
:id => "12345",
:bucket_1_rank => "2",
:bucket_1_count => "12",
:bucket_2_rank => "7",
:bucket_2_count => "25"
},
{
:id => "45678",
:bucket_1_rank => "2",
:bucket_1_count => "15",
:bucket_2_rank => "9",
:bucket_2_count => "68"
},
{
:id => "78901",
:bucket_1_rank => "5",
:bucket_1_count => "36"
}
]
The ranks values are always between 1 and 10.
What I am trying to do is select each of the possible values for the rank fields (the :bucket_1_rank and :bucket_2_rank fields) as keys in my final resultset, and the values for each key will be an array of all the values in its associated :bucket_count field. So, for the data above, the final resulting structure I have in mind is something like:
bucket 1:
{"2" => ["12", "15"], "5" => ["36"]}
bucket 2:
{"7" => ["25"], "9" => ["68"]}
I can do this working under the assumption that the field names stay the same, or through hard coding the field/key names, or just using group_by for the fields I need, but my problem is that I work with a different data set each month where the rank fields are named slightly differently depending on the project specs, and I want to identify the names for the count and rank fields dynamically as opposed to hard coding the field names.
I wrote two quick helpers get_ranks and get_buckets that use regex to return an array of fieldnames that are either ranks or count fields, since these fields will always have the literal string "_rank" or "_count" in their names:
ranks = get_ranks
counts = get_counts
results = Hash.new{|h,k| h[k] = []}
data.each do |i|
ranks.each do |r|
unless i[r].nil?
counts.each do |c|
results[i[r]] << i[c]
end
end
end
end
p results
This seems to be close, but feels awkward, and it seems to me there has to be a better way to iterate through this data set. Since I haven't worked on this project using Ruby I'd use this as an opportunity to improve my understanding iterating through arrays of hashes, populating a hash with arrays as values, etc. Any resources/suggestions would be much appreciated.
You could shorten it to:
result = Hash.new{|h,k| h[k] = Hash.new{|h2,k2| h2[k2] = []}}
data.each do |hsh|
hsh.each do |key, value|
result[$1][value] << hsh["#{$1}_count".to_sym] if key =~ /(.*)_rank$/
end
end
puts result
#=> {"bucket_1"=>{"2"=>["12", "15"], "5"=>["36"]}, "bucket_2"=>{"7"=>["25"], "9"=>["68"]}}
Though this is assuming that :bucket_2_item_count is actually supposed to be :bucket_2_count.