There are three hashes. Each hash results in a single key/value pair.
When merged and outputted to a json file, the only k/v pairs visible are the ones with data.
For example:
employee_hours[ name ] = {"Hours" => hours}
employee_revenue [ name ] = {"Revenue" => revenue}
employee_activations [ name ] = {"Activations" => activations}
If any of the k/v pairs don't exist I need them to be included in the output with a value of 0.00.
I tried to simply just include empty k/v pairs from the other hashes in each hashtable, but when merged, they overwrite existed values.
employee_hours[ name ] = {"Hours" => hours, "Revenue" = "", Activations = ""}
employee_revenue [ name ] = {"Hours" => "", "Revenue" => revenue, Activations = ""}
employee_activations [ name ] = {"Hours" => "", "Revenue" => "", "Activations" => activations}
Edit
My current code is listed here: https://gist.github.com/hnanon/766a0d6b2b0f9d9d03fd
You need to define a hash for the default values and merge into it. Assuming that employee_final is the hash where you merged all the employee information,
employee_defaults = { "Hours" => 0.0, "Revenue" => 0.0 }
employee_final.each_key do |name|
employee_final[name] = employee_defaults.merge(employee_final[name])
end
It sounds as if you need to define a 'REQUIRED_KEYS' array, and add check on their existence in your hashes. Here's one way to achieve that:
REQUIRED_KEYS = [ "A", "B", "C" ]
DEFAULT_VALUE = 0.0
REQUIRED_KEYS.each { |key| your_hash[key] = DEFAULT_VALUE if not your_hash.has_key?(key) }
Use Hash Defaults
You can use an argument to Hash#new to set a default value for a hash. For example:
require 'json'
employee_hours = Hash.new(0.0)
employee_revenue = Hash.new(0.0)
employee_activations = Hash.new(0.0)
name = 'Bob'
{
'Hours' => employee_hours[name],
'Revenue' => employee_revenue[name],
'Activations' => employee_activations[name],
}.to_json
# => "{\"Hours\":0.0,\"Revenue\":0.0,\"Activations\":0.0}"
Related
Suppose I have a hash,
hash = { "name" = > nil, "product" => nil , "price" => nil }
and an array
a = [ "Bob" , "Fryer" , "20$"]
I would like the output be hash
{ "name" => "Bob" , "product" => "Fryer" , "price" => "20$"}
Tried with zip, merge and map, couldn't get the right one
Try
Hash[hash.keys.zip(a)]
=> {"name"=>"Bob", "product"=>"Fryer", "price"=>"20$"}
You can get keys and zip it with array:
hash.keys.zip(a).to_h
=> {"name"=>"Bob", "product"=>"Fryer", "price"=>"20$"}
I have a user inputed string called x_value whose value contains something like ticker|high. Whenever there is a |, that indicates that the latter is a child of the former. The purpose of the method is to return a specific value within a hash.
sections = []
object.x_value.split('|').each do |part|
sections << part.to_sym
end
I then want to drill down the data hash and retrieve the value of the last key.
data = {"ticker":{"high":529.5,"low":465,"avg":497.25,"vol":7520812.018}}
In this example
data[sections[0]][sections[1]] returns the expected 529.5 value. However, the user may have different hashes and different levels deep of nested key/values. How can I write this?
I have tried data[sections], but that didn't work.
Use Enumerable#reduce
data = {"ticker" => {"high" => 529.5, "low" => 465,"avg" => 497.25,"vol" => 7520812.018}}
"ticker|high".split('|').reduce(data) { |dat,val| dat[val] } #=> 592.5
more example:
data = {"more_ticker" => {"ticker" => {"high" => 529.5, "low" => 465,"avg" => 497.25,"vol" => 7520812.018}}}
"more_ticker|ticker|avg".split('|').reduce(data) { |dat,val| dat[val] }
#=> 497.25
You could also use recursion:
def getit(hash, x_value)
recurse(hash, x_value.split('|'))
end
def recurse(hash, keys)
k = keys.shift
keys.empty? ? hash[k] : recurse(hash[k], keys)
end
data = {"ticker" => {"high" => 529.5, "low" => 465}}
getit(data, "ticker|high") #=> 529.5
getit(data, "ticker") #=> {"high"=>529.5, "low"=>465}
data = {"more_ticker" => {"ticker" => {"high" => 529.5, "low" => 465}}}
getit(data, "more_ticker|ticker|low") #=> 465
getit(data, "more_ticker|ticker|avg") #=> nil
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.
Let's say I have the following array of hashes:
h = [{"name" => "bob"}, {"car" => "toyota"}, {"age" => "25"}]
And I have the following key to match:
k = 'car'
How do I match the 'k' to 'h' and have delete every element after the match so that it returns:
h = [{"name" => "bob"}, {"car" => "toyota"}]
Just convert hash to array, do your task and then convert back
h = {"name" => "bob", "car" => "toyota", "age" => "25"}
array = h.to_a.flatten
index = array.index('car') + 1
h = Hash[*array[0..index]]
=> {"name"=>"bob", "car"=>"toyota"}
By the way, the hash is ordered only since Ruby 1.9
ar = [{"name" => "bob"}, {"car" => "toyota"}, {"age" => "25"}]
p ar[0 .. ar.index{|h| h.key?('car')}] #=>[{"name"=>"bob"}, {"car"=>"toyota"}]
I like megas' version, as its short and to the point. Another approach, which would be more explicit, would be iterating over the keys array of each hash. The keys of a hash are maintained in an ordered array (http://ruby-doc.org/core-1.9.3/Hash.html). They are ordered by when they were first entered. As a result, you can try the following:
newArray = Array.new
h.each do |hash| # Iterate through your array of hashes
newArray << hash
if hash.has_key?("car") # check if this hash is the "car" hash.
break # exits the block
end
end
This all depends, of course, on whether the array was created in the proper order. If it was, then you're golden.
A hash is unordered set by definition, so what you request is somewhat undefined. However you can do something like a hack:
h = {"name" => "bob", "car" => "toyota", "age" => "25"}
matched = false
key_given = "car"
h.each do |k,v|
if matched
h.delete(k)
end
if k == key_given
matched = true
next
end
end
I'm pretty late to the party here. I was looking for a solution to this same problem, but I didn't love these answers. So, here's my approach:
class Array
def take_until(&blk)
i = find_index &blk
take(i + 1)
end
end
h = [{"name" => "bob"}, {"car" => "toyota"}, {"age" => "25"}]
k = 'car'
h.take_until { |x| x.has_key?(k) }
=> [{"name"=>"bob"}, {"car"=>"toyota"}]
I'm trying to get the first key and value key from a hash table in ruby. I don't know the key values of the hash because it is passed to the method. I cant find anywhere online how to find the first key/value as a separate hash table.
I think hash[0] will just try to find an element with a name 0 it just returns nil when I run the code.
I know I can find the key name and the value and then create a new hash from them but i wonder if there is an easier way to do this so I get a hash right away.
here is my code:
def rps_game_winner(game)
rock_in_hash = game.invert['R']
paper_in_hash = game.invert['P']
scissors_in_hash = game.invert['S']
if(rock_in_hash)
if(paper_in_hash)
return paper_in_hash;
elsif(scissors_in_hash)
return rock_in_hash
end
elsif(paper_in_hash)
if(rock_in_hash)
return paper_in_hash
elsif(scissors_in_hash)
return scissors_in_hash
end
end
key = game.keys[-1]
value = game.values[-1]
winner = {key => value}
return winner
end
game_one = { "Bob" => 'P', "Jim" => 'P' }
puts rps_game_winner(game_one)
This gets me the correct result the problem is I don't understand why it's -1 instead of zero...
And i was hoping there was a better way to get the first key/value pair of a hash table instead of creating new hash table with the key and value you retrieved from the previous table.
You can just do
key, value = hash.first
or if you prefer:
key = hash.keys[0]
value = hash.values[0]
Then maybe:
new_hash = {key => value}
There is a shorter answer that does not require you to use extra variables:
h = { "a" => 100, "b" => 200 , "c" => 300, "d" => 400, "e" => 500}
Hash[*h.first] #=> {"a" => 100}
Or if you want to retrieve a key/value at a any single position
Hash[*h.to_a.at(1)] #=> {"b" => 200}
Or retrieve a key/values from a range of positions:
Hash[h.to_a[1,3]] #=> {"b"=>200, "c"=>300, "d"=>400}
[hash.first].to_h
Another way to do it.
my_hash = { "a" => "first", "b" => "second" }
{ my_hash.keys.first => my_hash.values.first }
This works too