I'm new to ruby i would like to know how can i split element containing special character.
I have the following array :
my_array = ["sh.please-word", ".things-to-do" , "#cool-stuff", "span.please-word-not"]
my_array.slice!(0..1)
puts my_array
=>#cool-stuff
=>span.please-word
i want it to split array elements that doesn't start with either a dot(.) or a (#) and return the list like this:
.please-word
.things-to-do
#cool_stuff
.please-word-not
i tried to use the slice method for a string which works perfectly, but when i try with the array element it doesn't work.
this is what i have done so far.
list_of_selectors = []
file = File.open("my.txt")
file.each_line do |line|
list_of_selectors << line.split(' {')[0] if line.start_with? '.' or line.start_with? '#'
end
while line = file.gets
puts line
end
i = 0
while i < list_of_selectors.length
puts "#{list_of_selectors[i]}"
i += 1
end
list = []
list_of_selectors.each { |x|
list.push(x.to_s.split(' '))
}
list_of_selectors = list
puts list_of_selectors
list_of_selectors.map! { |e| e[/[.#].*/]}
puts list_of_selectors
result_array = my_array.map { |x| x[/[.#].*/] }
# => [".please-word", ".things-to-do", "#cool-stuff", ".please-word-not"]
The above uses a regular expression to extract the text, beginning with either a dot(.) or a hashtag (#), and return it in the resulting array.
Related
Hey I've a little problem, I've a string array text_word and I want to replace some letters with my file transform.txt, my file looks like this:
/t/ 3
/$/ 1
/a/ !
But when I use gsub I get an Enumerator back, does anyone know how to fix this?
text_transform= Array.new
new_words= Array.new
File.open("transform.txt", "r") do |fi|
fi.each_line do |words|
text_transform << words.chomp
end
end
text_transform.each do |transform|
text_word.each do |words|
new_words << words.gsub(transform)
end
end
You can see String#gsub
If the second argument is a Hash, and the matched text is one of its
keys, the corresponding value is the replacement string.
Also you can use IO::readlines
File.readlines('transform.txt', chomp: true).map { |word| word.gsub(/[t$a]/, 't' => 3, '$' => 1, 'a' => '!') }
gsub returns an Enumerator when you provide just one argument (the pattern). If you want to replace just add the replacement string:
pry(main)> 'this is my string'.gsub(/i/, '1')
"th1s 1s my str1ng"
You need to refactor your code:
text_transform = Array.new
new_words = Array.new
File.open("transform.txt", "r") do |fi|
fi.each_line do |words|
text_transform << words.chomp.strip.split # "/t/ 3" -> ["/t/", "3"]
end
end
text_transform.each do |pattern, replacement| # pattern = "/t/", replacement = "3"
text_word.each do |words|
new_words << words.gsub(pattern, replacement)
end
end
I want to sort through a text file and leave only a certain section. I have this text in the text file:
{
"id"=>”0000001”,
"type"=>”cashier”,
"summary"=>”Henock”,
"self"=>"https://google.com/accounts/0000001”,
"html_url"=>"https://google.com/accounts/0000001”
}
{
"id"=>”0000002”,
"type"=>”cashier”,
"summary"=>”Vic”,
"self"=>"https://google.com/accounts/0000002”,
"html_url"=>"https://google.com/accounts/0000002”
}
{
"id"=>”0000003”,
"type"=>”cashier”,
"summary"=>”Mo”,
"self"=>"https://google.com/accounts/0000003”,
"html_url"=>"https://google.com/accounts/0000003”
}
How would I sort it so that only the information with person "Mo" is shown?
This is what I tried:
somefile.readlines("filename.txt").grep /Mo}/i
but it is useless.
Code
def retrieve_block(fname, summary_target)
arr = []
File.foreach(fname) do |line|
next if line.strip.empty?
arr << line
next unless arr.size == 7
return arr.join if arr[3].match?(/\"summary\"=>\"#{summary_target}\"/)
arr = []
end
end
Example
Let's first create a file.
text =<<_
{
"id"=>"0000001",
"type"=>"cashier",
"summary"=>"Henock",
"self"=>"https://google.com/accounts/0000001",
"html_url"=>"https://google.com/accounts/0000001"
}
{
"id"=>"0000003",
"type"=>"cashier",
"summary"=>"Mo",
"self"=>"https://google.com/accounts/0000003",
"html_url"=>"https://google.com/accounts/0000003"
}
_
All of the keys and values represented in this string are surrounded with double-quotes. In the question however, many of these keys and values are surrounded by special characters that have a superficial appearance of a double quote. I have assumed that those characters would be converted to double quotes in a pre-processing step.
FName = "test"
File.write(FName, text)
#=> 325
puts retrieve_block(FName, "Mo")
{
"id"=>"0000003",
"type"=>"cashier",
"summary"=>"Mo",
"self"=>"https://google.com/accounts/0000003",
"html_url"=>"https://google.com/accounts/0000003"
}
This should work because of the consistent format of the file.
To return a hash, rather than a string, a slight modification is required.
def retrieve_block(fname, summary_target)
h = {}
File.foreach(fname) do |line|
line.strip!
next if line.empty? || line == '{'
if line == '}'
if h["summary"] == summary_target
break h
else
h = {}
end
else
k, v = line.delete('",').split("=>")
h[k] = v
end
end
end
retrieve_block(FName, "Mo")
#=> {"id"=>"0000003",
# "type"=>"cashier",
# "summary"=>"Mo",
# "self"=>"https://google.com/accounts/0000003",
# "html_url"=>"https://google.com/accounts/0000003"}
I am writing a braille converter. I have this method to handle the top line of a braille character:
def top(input)
braille = ""
#output_first = ""
#top.each do |k, v|
input.chars.map do |val|
if k.include?(val)
braille = val
braille = braille.gsub(val, v)
#output_first = #output_first + braille
end
end
end
#output_first
end
I'm repeating the same each loop for the middle and bottom lines of a character. The only thing that is different from the method above is that the #top is replaced with #mid and #bottom to correspond to the respective lines.
Trying to figure a way to simplify the each loop so I can call it on top, mid and bottom lines.
You can put the loop in a separate method.
def top(input)
#output_first = handle_line(#top)
end
def handle_line(line)
result = ''
line.each do |k, v|
input.chars.map do |val|
if k.include?(val)
braille = val
braille = braille.gsub(val, v)
result = result + braille
end
end
end
result
end
You can then call handle_line in your #mid and #bottom processing
I'm not sure whats in the #top var but I believe braille has limited number of characters and therefore I would consider some map structure
BRAILLE_MAP = {
'a' => ['..',' .','. '], # just an example top,mid,bot line for character
'b' => ['..','..',' '],
# ... whole map
}
def lines(input)
top = '' # representation of each line
mid = ''
bot = ''
input.each_char do |c|
representation = BRAILLE_MAP[c]
next unless representation # handle invalid char
top << representation[0] # add representation to each line
mid << representation[1]
bot << representation[2]
end
[top,mid,bot] # return the lines
end
There may be better way to handle those 3 variables, but I cant think of one right now
I am trying to create a program where by the user can enter multiple names. those names are then displayed under each other in alphabetical order, and print(display) every second name backwards. i have gone through several tutorials this is my second day using ruby.. here is what i have so far.
name_list = {}
puts 'please enter names seperated by a space:'
name_list = gets.chomp
names = name_list.split(" ")
to grab names...
names.sort do |a,b| a.upcase <=> b.upcase end
display = "#{names}"
for ss in 0...display.length
print ss, ": ", display[ss], "\n"
end
to arrange them alphabetically and under each other.
i am really struggling to mesh it all together i think i have got at least half a dozen errors in here...if i am on the wrong path could someone guide me to some info so i can start again??
EDIT
i also had this idea of using a class.
but i would have to program the names in i wanted the user to be able to add info via the consol.
class A
def initialize(name)
#name = name
end
def to_s
#name.reverse
end
end
>> a = [A.new("greg"),A.new("pete"),A.new("paul")]
>> puts a
Problems in your code:
name_list defined as an empty hash at the top but not used.
split(" ") -> split
sort { |a, b| a.method <=> b.method } -> sort_by { |x| x.method } -> sort_by(&:method)
sort is not an in-place operation, assign the result (or directly use it).
display = "#{names}" -> display = names
for ss in 0...display.length -> enumerable.each_with_index { |item, index| ... }
don't write do/end in one-liners, use { ... }
I'd write:
puts 'Please enter names separated by spaces'
gets.split.sort_by(&:upcase).each_with_index do |name, index|
puts "%s: %s" % [index, (index % 2).zero? ? name : name.reverse]
end
A few pointers then:
names.sort do |a,b| a.upcase <=> b.upcase end # Will not modify the "names" array, but will return a sorted array.
names.sort! do |a,b| a.upcase <=> b.upcase end # Will modify the "names" array.
To display your names:
names.each_with_index do |name, index|
if index % 2 == 0
puts name
else
puts name.reverse
end
end
puts 'please enter names seperated by a space`enter code here` :'
names = gets.chomp.split(" ")
names.sort! {|a,b| a.upcase <=> b.upcase } # For a single line use {..} instead of do..end
names.each_with_index do |n,i|
if i % 2 == 0
p n
else
p n.reverse
end
end
You can also use a ternary operator, I used the full if else block for readability in this case.
names.each_with_index do |n,i|
p (i % 2 == 0) ? n : n.reverse
end
EDIT
command = ""
names = []
while command != "exit"
puts 'please enter names seperated by a space`enter code here` :'
command = gets.chomp!
if command == "display"
names.sort! {|a,b| a.upcase <=> b.upcase } # For a single line use {..} instead of do..end
names.each_with_index do |n,i|
if i % 2 == 0
p n
else
p n.reverse
end
end
else
names << command
end
end
I have array which I read from excel (using ParseExcel) using the following code:
workbook = Spreadsheet::ParseExcel.parse("test.xls")
rows = workbook.worksheet(1).map() { |r| r }.compact
grid = rows.map() { |r| r.map() { |c| c.to_s('latin1') unless c.nil?}.compact rescue nil }
grid.sort_by { |k| k[2]}
test.xls has lots of rows and 6 columns. The code above sort by column 3.
I would like to output rows in array "grid" to many text file like this:
- After sorting, I want to print out all the rows where column 3 have the same value into one file and so on for a different file for other same value in column3.
Hope I explain this right. Thanks for any help/tips.
ps.
I search through most posting on this site but could not find any solution.
instead of using your above code, I made a test 100-row array, each row containing a 6-element array.
You pass in the array, and the column number you want matched, and this method prints into separate files rows that have the same nth element.
Since I used integers, I used the nth element of each row as the filename. You could use a counter, or the md5 of the element, or something like that, if your nth element does not make a good filename.
a = []
100.times do
b = []
6.times do
b.push rand(10)
end
a.push(b)
end
def print_files(a, column)
h = Hash.new
a.each do |element|
h[element[2]] ? (h[element[column]] = h[element[column]].push(element)) : (h[element[column]] = [element])
end
h.each do |k, v|
File.open("output/" + k.to_s, 'w') do |f|
v.each do |line|
f.puts line.join(", ")
end
end
end
end
print_files(a, 2)
Here is the same code using blocks instead of do .. end:
a = Array.new
100.times{b = Array.new;6.times{b.push rand(10)};a.push(b)}
def print_files(a, column)
h = Hash.new
a.each{|element| h[element[2]] ? (h[element[column]] = h[element[column]].push(element)) : (h[element[column]] = [element])}
h.map{|k, v| File.open("output/" + k.to_s, 'w'){|f| v.map{|line| f.puts line.join(", ")}}}
end
print_files(a, 2)