My question is, how can I search through an array and replace the string at the current index of the search without knowing what the indexed array string contains?
The code below will search through an ajax file hosted on the internet, it will find the inventory, go through each weapon in my inventory, adding the ID to a string (so I can check if that weapon has been checked before). Then it will add another value after that of the amount of times it occurs in the inventory, then after I have check all weapon in the inventory, it will go through the all of the IDs added to the string and display them along with the number (amount of occurrences). This is so I know how many of each weapon I have.
This is an example of what I have:
strList = ""
inventory.each do |inv|
amount = 1
exists = false
ids = strList.split(',')
ids.each do |ind|
if (inv['id'] == ind.split('/').first) then
exists = true
amount = ind.split('/').first.to_i
amount += 1
ind = "#{inv['id']}/#{amount.to_s}" # This doesn't seem work as expected.
end
end
if (exists == true) then
ids.push("#{inv['id']}/#{amount.to_s}")
strList = ids.join(",")
end
end
strList.split(",").each do |item|
puts "#{item.split('/').first} (#{item.split('/').last})"
end
Here is an idea of what code I expected (pseudo-code):
inventory = get_inventory()
drawn_inv = ""
loop.inventory do |inv|
if (inv['id'].occurred_before?)
inv['id'].count += 1
end
end loop
loop.inventory do |inv|
drawn_inv.add(inv['id'] + "/" + inv['id'].count)
end loop
loop.drawn_inv do |inv|
puts "#{inv}"
end loop
Any help on how to replace that line is appreciated!
EDIT: Sorry for not requiring more information on my code. I skipped the less important part at the bottom of the code and displayed commented code instead of actual code, I'll add that now.
EDIT #2: I'll update my description of what it does and what I'm expecting as a result.
EDIT #3: Added pseudo-code.
Thanks in advance,
SteTrezla
You want #each_with_index: http://ruby-doc.org/core-2.2.0/Enumerable.html#method-i-each_with_index
You may also want to look at #gsub since it takes a block. You may not need to split this string into an array at all. Basically something like strList.gsub(...){ |match| #...your block }
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The program reads in a file of tracks and produces a Track array (tracks). When the user searches for a specific track (search_string) the program returns that it cannot be found, despite there being a track with that name in the array.
class Track
attr_accessor :name, :location
def initialize (name, location)
#name = name
#location = location
end
end
# search for track by name.
# Returns the index of the track or -1 if not found
def search_for_track_name(tracks, search_string)
search_string = gets.chomp
index = 0
while (index < tracks.length)
tracks.include?(search_string)
index = index + 1
end
if tracks.include?(search_string)
return index
else
index = -1
end
return index
end
The condition if tracks.include?(search_string) will never be true because tracks is an array of instances of Track. And therefore the array doesn't include a specific string.
It might include a track which has a matching name. To find the index of a track that has a matching name Array#index might help:
tracks.index { |track| track.name == search_string }
Because index returns nil if the value is not found you can simplify your whole if...else block and probably the whole search_for_track_name method to just this line:
tracks.index { |track| track.name == search_string } || -1
I notice your searching loop does nothing. It checks N times if the array includes the search string, ignores the result of that check, and adds one to the index. So the index is always going to be N (3 in your case). Then you check again whether the array includes the search string, and return -1 if you don't. So your method will always return either N or -1.
Fortunately, Ruby is a language which has already done a lot of the heavy lifting for you. Quite frankly I think you want:
def search_for_track_name(tracks, search_string)
tracks.index(search_string) || -1
end
#index would return nil if the search string is not found; this is more standard for Ruby, but since your requirement is to return -1, the || -1 will put it in for you. (nil and false are the only falsy values in Ruby, so || is a convenient way to shortcut to a default object if the first part is nil.)
I've also just noticed something else, and I think it might be the problem. Do you by any chance have to press Enter twice? Because the first input from read_string will get overwritten by search_string = gets.chomp. You already set search_string before you passed it to the method...
Third thing I've noticed - your track names are being populated with newlines (\n). You'll need to chomp them as well, or follow other users' advice and look for partial matches instead of exact ones.
I've read through tons of questions and solutions to determine whether this was already answered elsewhere, but it seems that none of the things I found were exactly what I was trying to get at.
I have an XML document that has hundreds of entries of text, and each entry also lists a URL. Each URL is a string (within tags), ending with a unique 4-digit number. The XML file is basically formatted like so:
<entry>
[other content]
<id>http://www.URL.com/blahblahblah-1234</id>
[other content]
</entry>
I want to essentially single out only the URLs that have a particular number at the end, out of a list of numbers. I put all of the numbers in an array, with the values set as strings ( numbers = ["1234", "8649", etc.]). I've been using nokogiri for other parts of my script, and when I am only looking for a particular string, I just use include?, which works perfectly. However, I'm not sure how to automate this when I have hundreds of strings within the "numbers" array. This is essentially what I logistically need to happen:
id = nokodoc.css("id")
id.each { |id|
hyperlink = id.text
if hyperlink.include?(numbers)
puts "yes!"
else
puts "no :("
end
}
Obviously this doesn't work, because include? expects a string, whereas I'm passing an entire array. (For instance, if I do include?(numbers[0]), it works.) I've tried this with any? but it doesn't seem to work in this case.
Is there a Ruby method that I'm not aware of, that can tell me whether any of the values within an array is present in any of the nodes that I'm looping through? Let me know if any of this needs to be clarified—phrasing the proper question is often the hardest part!
Edit: As a sidenote, ultimately I'd like to remove all entries that correspond to any links that do not end with one of the numbers in the array, i.e.
if hyperlink.include? (any number from the array)
puts "this one is good"
else
id.parent.remove
So I would somehow need the final product to remain parsable with nokogiri.
Thank you so much in advance, for any and all insight!
You can do this:
numbers = ['1234', '8649', ..]
urls = nokodoc.css('id').map(&:text)
urls = urls.select { |url| numbers.any? { |n| url.include? n } }
But it's not efficient. If you know the pattern -- extract the number, and then check if it's in the array. For example, if it's always last 4 digits:
numbers = ['1234', '8649', ..]
urls = nokodoc.css('id').map(&:text)
urls = urls.select { |url| numbers.include? url[-4..-1] }
UPDATE
For the change in the question:
numbers = ['1234', '8649', ..]
nodes = nokodoc.css('id')
nodes.each do |node|
url = node.text
if numbers.any? { |n| url.include? n }
puts 'this one is good'
else
node.parent.remove
end
end
So, What I'm trying to do is make calls to a Reporting API to filter by all possible breakdowns (breakdown the reports by site, avertiser, ad type, campaign, etc...). But, one issue is that the breakdowns can be unique to each login.
Example:
user1: alice123's reporting breakdowns are ["site","advertiser","ad_type","campaign","line_items"]
user2: bob789's reporting breakdowns are ["campaign","position","line_items"]
When I first built the code for this reporting API, I only had one login to test with, so I hard coded the loops for the dimensions (["site","advertiser","ad_type","campaign","line_items"]). So what I did was pinged the API for a report by sites. Then for each site, pinged for advertisers, and each advertiser, I pinged for the next dimension and so on..., leaving me with a nested loop of ~6 layers.
basically what I'm doing:
sites = mechanize.get "#{base_ur}/report?dim=sites"
sites = Yajl::Parser.parse(sites.body) # json parser
sites.each do |site|
advertisers = mechanize.get "#{base_ur}/report?site=#{site.fetch("id")}&dim=advertiser"
advertisers = Yajl::Parser.parse(advertisers.body) # json parser
advertisers.each do |advertiser|
ad_types = mechanize.get "#{base_ur}/report?site=#{site.fetch("id")}&advertiser=#{advertiser.fetch("id")}&dim=ad_type"
ad_types = Yajl::Parser.parse(ad_types.body) # json parser
ad_types.each do |ad_type|
...and so on...
end
end
end
GET <api_url>/?dim=<dimension to breakdown>&site=<filter by site id>&advertiser=<filter by advertiser id>...etc...
At the end of the nested loop, I'm left with a report that's broken down as much granularity as possible.
This works now since I only thought that there was one path of breaking down, but apparently each account could have different dimensions breakdowns.
So what I'm asking is if given an array of breakdowns, how can I set up a nested loop to traverse down dynamically do the granularity singularity?
Thanks.
I'm not sure what your JSON/GET returns exactly but for a problem like this you would need recursion.
Something like this perhaps? It's not very elegant and can definitely be optimised further but should hopefully give you an idea.
some_hash = {:id=>"site-id", :body=>{:id=>"advertiser-id", :body=>{:id=>"ad_type-id", :body=>{:id=>"something-id"}}}}
#breakdowns = ["site", "advertiser", "ad_type", "something"]
def recursive(some_hash, str = nil, i = 0)
if #breakdowns[i+1].nil?
str += "#{#breakdowns[i]}=#{some_hash[:id]}"
else
str += "#{#breakdowns[i]}=#{some_hash[:id]}&dim=#{#breakdowns[i + 1]}"
end
p str
some_hash[:body].is_a?(Hash) ? recursive(some_hash[:body], str.gsub(/dim.*/, ''), i + 1) : return
end
recursive(some_hash, 'base-url/report?')
=> "base-url/report?site=site-id&dim=advertiser"
=> "base-url/report?site=site-id&advertiser=advertiser-id&dim=ad_type"
=> "base-url/report?site=site-id&advertiser=advertiser-id&ad_type=ad_type-id&dim=something"
=> "base-url/report?site=site-id&advertiser=advertiser-id&ad_type=ad_type-id&something=something-id"
If you are just looking to map your data, you can recursively map to a hash as another user pointed out. If you are actually looking to do something with this data while within the loop and want to dynamically recreate the loop structure you listed in your question (though I would advise coming up with a different solution), you can use metaprogramming as follows:
require 'active_support/inflector'
# Assume we are given an input of breakdowns
# I put 'testarr' in place of the operations you perform on each local variable
# for brevity and so you can see that the code works.
# You will have to modify to suit your needs
result = []
testarr = [1,2,3]
b = binding
breakdowns.each do |breakdown|
snippet = <<-END
eval("#{breakdown.pluralize} = testarr", b)
eval("#{breakdown.pluralize}", b).each do |#{breakdown}|
END
result << snippet
end
result << "end\n"*breakdowns.length
eval(result.join)
Note: This method is probably frowned upon, and as I've said I'm sure there are other methods of accomplishing what you are trying to do.
I'd like to use Builder to construct a set of XML files based on a table of ActiveRecord models. I have nearly a million rows, so I need to use find_each(batch_size: 5000) to iterate over the records and write an XML file for each batch of them, until the records are exhausted. Something like the following:
filecount = 1
count = 0
xml = ""
Person.find_each(batch_size: 5000) do |person|
xml += person.to_xml # pretend .to_xml() exists
count += 1
if count == MAX_PER_FILE
File.open("#{filecount}.xml", 'w') {|f| f.write(xml) }
xml = ""
filecount += 1
count = 0
end
end
This doesn't work well with Builder's interface, as it wants to work in blocks, like so:
xml = builder.person { |p| p.name("Jim") }
Once the block ends, Builder closes its current stanza; you can't keep a reference to p and use it outside of the block (I tried). Basically, Builder wants to "own" the iteration.
So to make this work with builder, I'd have to do something like:
filecount = 0
offset = 0
while offset < Person.count do
count = 0
builder = Builder::XmlMarkup.new(indent: 5)
xml = builder.people do |people|
Person.limit(MAX_PER_FILE).offset(offset).each do |person|
people.person { |p| p.name(person.name) }
count += 1
end
end
File.open("#output#file_count.xml", 'w') {|f| f.write(xml) }
filecount += 1
offset += count
end
Is there a way to use Builder without the block syntax? Is there a way to programmatically tell it "close the current stanza" rather than relying on a block?
My suggestion: don't use builder.
XML is a simple format as long as you escape the xml entities correctly.
Batch your db retrieve then just write out the batch as xml to a file handle. Don't buffer via a string as your example shows. Just write to the filehandle. Let the OS deal with buffering. Files can be of any size, why the limit?
Also, don't include the indentation spaces, with million rows, they'd add up.
Added
When writing xml files, I also include xml comments at the top of the file:
The name of the software and version that generated the xml file
Date / timestamp the file was written
Other useful info. Eg in this case you could say that the file is batch # x of the original data set.
I ended up generating the XML manually, as per Larry K's suggestion. Ruby's built-in XML encoding made this a piece of cake. I'm not sure why this feature not more widely advertised... I wasted a lot of time Googling and trying various to_xs implementations before I stumbled upon the built-in "foo".encode(xml: :text).
My code now looks like:
def run
count = 0
Person.find_each(batch_size: 5000) do |person|
open_new_file if #current_file.nil?
# simplified- I actually have many more fields and elements
#
#current_file.puts " <person>#{person.name.encode(xml: :text)}</person>"
count += 1
if count == MAX_PER_FILE
close_current_file
count = 0
end
end
close_current_file
end
def open_new_file
#file_count += 1
#current_file = File.open("people#{#file_count}.xml", 'w')
#current_file.puts "<?xml version='1.0' encoding='UTF-8'?>"
#current_file.puts " <people>"
end
def close_current_file
unless #current_file.nil?
#current_file.puts " </people>"
#current_file.close
#current_file = nil
end
end
I wrote a Secret Santa program (ala Ruby Quiz...ish), but occasionally when the program runs, I get an error.
Stats: If there's 10 names in the pot, the error comes up about 5% of the time. If there's 100 names in the pot, it's less than 1%. This is on a trial of 1000 times in bash. I've determined that the gift arrays are coming up nil at some point, but I'm not sure why or how to avoid it.
Providing code...
0.upto($lname.length-1).each do |i|
j = rand($giftlname.length) # should be less each time.
while $giftlname[j] == $lname[i] # redo random if it picks same person
if $lname[i] == $lname.last # if random gives same output again, means person is left with himself; needs to switch with someone
$giftfname[j], $fname[i] = $giftfname[i], $fname[j]
$giftlname[j], $lname[i] = $giftlname[i], $lname[j]
$giftemail[j], $email[i] = $giftemail[i], $email[j]
else
j = rand($giftlname.length)
end
end
$santas.push('Santa ' + $fname[i] + ' ' + $lname[i] + ' sends gift to ' + $giftfname[j] + ' ' + $giftlname[j] + ' at ' + '<' + $giftemail[j] + '>.') #Error here, something is sometimes nil
$giftfname.delete_at(j)
$giftlname.delete_at(j)
$giftemail.delete_at(j)
end
Thanks SO!
I think your problem is right here:
$giftfname[j], $fname[i] = $giftfname[i], $fname[j]
Your i values range between zero to the last index in $fname (inclusive) and, presumably, your $giftfname starts off as a clone of $fname (or at least another array with the same length). But, as you spin through the each, you're shrinking $giftfname so $giftfname[i] will be nil and the swap operation above will put nil into $giftfname[j] (which is supposed to be a useful entry of $giftfname). Similar issues apply to $giftlname and $giftemail.
I'd recommend using one array with three element objects (first name, last name, email) instead of your three parallel arrays. There's also a shuffle method on Array that might be of use to you:
Start with an array of people.
Make copy of that array.
Shuffle the copy until it is different at every index from that original array.
Then zip the together to get your final list of giver/receiver pairs.
Figured it out and used the retry statement. the if statement now looks like this (all other variables have been edited to be non-global as well)
if lname[i] == lname.last
santas = Array.new
giftfname = fname.clone
giftlname = lname.clone
giftemail = email.clone
retry
That, aside from a few other edits, created the solution I needed without breaking apart the code too much again. Will definitely try out mu's solution as well, but I'm just glad I have this running error-free for now.