I have a string like this
a="[\"6000208900\",\"600020890225\",\"600900231930\"]"
#expected result [6000208900,600020890225,600900231930]
I am trying to remove the backslash from the string.
a.gsub!(/^\"|\"?$/, '')
Inside the double quoted string(""), another double quotes must be escaped by \. You can't remove it.
Use puts, you can see it is not there.
a = "[\"6000208902912790\"]"
puts a # => ["6000208902912790"]
Or use JSON
irb(main):001:0> require 'json'
=> true
irb(main):002:0> a = "[\"6000208902912790\"]"
=> "[\"6000208902912790\"]"
irb(main):003:0> b = JSON.parse a
=> ["6000208902912790"]
irb(main):004:0> b
=> ["6000208902912790"]
irb(main):005:0> b.to_s
=> "[\"6000208902912790\"]"
update (as per the last edit of OP)
irb(main):002:0> a = "[\"6000208900\",\"600020890225\",\"600900231930\"]"
=> "[\"6000208900\",\"600020890225\",\"600900231930\"]"
irb(main):006:0> a.scan(/\d+/).map(&:to_i)
=> [6000208900, 600020890225, 600900231930]
irb(main):007:0>
The code a.gsub!(/^\"|\"?$/, '') can't remove the double quote characters because they are not at the beginning and the end of the string. To get what you want try this:
a.gsub(/((?<=^\[)")|("(?=\]$))/, '')
try this:
=> a = "[\"6000208902912790\"]"
=> a.chars.select{ |x| x =~ %r|\d| }.join
=> "6000208902912790"
=> [a.chars.select { |x| x =~ %r|\d| }.join]
=> ["6000208902912790"] # <= array with string
=> [a.chars.select { |x| x =~ %r|\d| }.join].to_s
=> "[\"6000208902912790\"]" # <= come back :)
a="["6000208902912790"]" will return `unexpected tINTEGER`error;
so a="[\"6000208902912790\"]"is used with \ character for double quotes.
As a solution you should try to remove double quotes that will solve the problem.
Do this
a.gsub!(/"/, '')
Related
How do I a string against a regex such that it will return true if the whole string matches (not a substring)?
eg:
test( \ee\ , "street" ) #=> returns false
test( \ee\ , "ee" ) #=> returns true!
Thank you.
You can match the beginning of the string with \A and the end with \Z. In ruby ^ and $ match also the beginning and end of the line, respectively:
>> "a\na" =~ /^a$/
=> 0
>> "a\na" =~ /\Aa\Z/
=> nil
>> "a\na" =~ /\Aa\na\Z/
=> 0
This seems to work for me, although it does look ugly (probably a more attractive way it can be done):
!(string =~ /^ee$/).nil?
Of course everything inside // above can be any regex you want.
Example:
>> string = "street"
=> "street"
>> !(string =~ /^ee$/).nil?
=> false
>> string = "ee"
=> "ee"
>> !(string =~ /^ee$/).nil?
=> true
Note: Tested in Rails console with ruby (1.8.7) and rails (3.1.1)
So, what you are asking is how to test whether the two strings are equal, right? Just use string equality! This passes every single one of the examples that both you and Tomas cited:
'ee' == 'street' # => false
'ee' == 'ee' # => true
"a\na" == 'a' # => false
"a\na" == "a\na" # => true
Is there any easy way to convert strings like 3500goat to 3500Goat and goat350rat to Goat350rat?
I am trying to convert the first occurrence of alphabet in an alphanumeric string to uppercase. I was trying the code below using the method sub, but no luck.
stringtomigrate = 3500goat
stringtomigrate.sub!(/\D{0,1}/) do |w|
w.capitalize
This should work:
string.sub(/[a-zA-Z]/) { |s| s.upcase }
or a shorthand:
string.sub(/[a-zA-Z]/, &:upcase)
examples:
'3500goat'.sub(/[a-zA-Z]/, &:upcase)
# => "3500Goat"
'goat350rat'.sub(/[a-zA-Z]/, &:upcase)
# => "Goat350rat"
Try this
1.9.3-p545 :060 > require 'active_support/core_ext'
=> true
1.9.3-p545 :099 > "goat350rat to Goat350rat".sub(/[a-zA-Z]/){ |x| x.titleize}
=> "Goat350rat to Goat350rat"
I have an Excel column containing part numbers. Here is a sample
As you can see, it can be many different datatypes: Float, Int, and String. I am using roo gem to read the file. The problem is that roo interprets integer cells as Float, adding a trailing zero to them (16431 => 16431.0). I want to trim this trailing zero. I cannot use to_i because it will trim all the trailing numbers of the cells that require a decimal in them (the first row in the above example) and will cut everything after a string char in the String rows (the last row in the above example).
Currently, I have a a method that checks the last two characters of the cell and trims them if they are ".0"
def trim(row)
if row[0].to_s[-2..-1] == ".0"
row[0] = row[0].to_s[0..-3]
end
end
This works, but it feels terrible and hacky. What is the proper way of getting my Excel file contents into a Ruby data structure?
def trim num
i, f = num.to_i, num.to_f
i == f ? i : f
end
trim(2.5) # => 2.5
trim(23) # => 23
or, from string:
def convert x
Float(x)
i, f = x.to_i, x.to_f
i == f ? i : f
rescue ArgumentError
x
end
convert("fjf") # => "fjf"
convert("2.5") # => 2.5
convert("23") # => 23
convert("2.0") # => 2
convert("1.00") # => 1
convert("1.10") # => 1.1
For those using Rails, ActionView has the number_with_precision method that takes a strip_insignificant_zeros: true argument to handle this.
number_with_precision(13.00, precision: 2, strip_insignificant_zeros: true)
# => 13
number_with_precision(13.25, precision: 2, strip_insignificant_zeros: true)
# => 13.25
See the number_with_precision documentation for more information.
This should cover your needs in most cases: some_value.gsub(/(\.)0+$/, '').
It trims all trailing zeroes and a decimal point followed only by zeroes. Otherwise, it leaves the string alone.
It's also very performant, as it is entirely string-based, requiring no floating point or integer conversions, assuming your input value is already a string:
Loading development environment (Rails 3.2.19)
irb(main):001:0> '123.0'.gsub(/(\.)0+$/, '')
=> "123"
irb(main):002:0> '123.000'.gsub(/(\.)0+$/, '')
=> "123"
irb(main):003:0> '123.560'.gsub(/(\.)0+$/, '')
=> "123.560"
irb(main):004:0> '123.'.gsub(/(\.)0+$/, '')
=> "123."
irb(main):005:0> '123'.gsub(/(\.)0+$/, '')
=> "123"
irb(main):006:0> '100'.gsub(/(\.)0+$/, '')
=> "100"
irb(main):007:0> '127.0.0.1'.gsub(/(\.)0+$/, '')
=> "127.0.0.1"
irb(main):008:0> '123xzy45'.gsub(/(\.)0+$/, '')
=> "123xzy45"
irb(main):009:0> '123xzy45.0'.gsub(/(\.)0+$/, '')
=> "123xzy45"
irb(main):010:0> 'Bobby McGee'.gsub(/(\.)0+$/, '')
=> "Bobby McGee"
irb(main):011:0>
Numeric values are returned as type :float
def convert_cell(cell)
if cell.is_a?(Float)
i = cell.to_i
cell == i.to_f ? i : cell
else
cell
end
end
convert_cell("foobar") # => "foobar"
convert_cell(123) # => 123
convert_cell(123.4) # => 123.4
I want to be able to check if a word is already all uppercase. And it might also include numbers.
Example:
GO234 => yes
Go234 => no
You can compare the string with the same string but in uppercase:
'go234' == 'go234'.upcase #=> false
'GO234' == 'GO234'.upcase #=> true
a = "Go234"
a.match(/\p{Lower}/) # => #<MatchData "o">
b = "GO234"
b.match(/\p{Lower}/) # => nil
c = "123"
c.match(/\p{Lower}/) # => nil
d = "µ"
d.match(/\p{Lower}/) # => #<MatchData "µ">
So when the match result is nil, it is in uppercase already, else something is in lowercase.
Thank you #mu is too short mentioned that we should use /\p{Lower}/ instead to match non-English lower case letters.
I am using the solution by #PeterWong and it works great as long as the string you're checking against doesn't contain any special characters (as pointed out in the comments).
However if you want to use it for strings like "Überall", just add this slight modification:
utf_pattern = Regexp.new("\\p{Lower}".force_encoding("UTF-8"))
a = "Go234"
a.match(utf_pattern) # => #<MatchData "o">
b = "GO234"
b.match(utf_pattern) # => nil
b = "ÜÖ234"
b.match(utf_pattern) # => nil
b = "Über234"
b.match(utf_pattern) # => #<MatchData "b">
Have fun!
You could either compare the string and string.upcase for equality (as shown by JCorc..)
irb(main):007:0> str = "Go234"
=> "Go234"
irb(main):008:0> str == str.upcase
=> false
OR
you could call arg.upcase! and check for nil. (But this will modify the original argument, so you may have to create a copy)
irb(main):001:0> "GO234".upcase!
=> nil
irb(main):002:0> "Go234".upcase!
=> "GO234"
Update: If you want this to work for unicode.. (multi-byte), then string#upcase won't work, you'd need the unicode-util gem mentioned in this SO question
How do I a string against a regex such that it will return true if the whole string matches (not a substring)?
eg:
test( \ee\ , "street" ) #=> returns false
test( \ee\ , "ee" ) #=> returns true!
Thank you.
You can match the beginning of the string with \A and the end with \Z. In ruby ^ and $ match also the beginning and end of the line, respectively:
>> "a\na" =~ /^a$/
=> 0
>> "a\na" =~ /\Aa\Z/
=> nil
>> "a\na" =~ /\Aa\na\Z/
=> 0
This seems to work for me, although it does look ugly (probably a more attractive way it can be done):
!(string =~ /^ee$/).nil?
Of course everything inside // above can be any regex you want.
Example:
>> string = "street"
=> "street"
>> !(string =~ /^ee$/).nil?
=> false
>> string = "ee"
=> "ee"
>> !(string =~ /^ee$/).nil?
=> true
Note: Tested in Rails console with ruby (1.8.7) and rails (3.1.1)
So, what you are asking is how to test whether the two strings are equal, right? Just use string equality! This passes every single one of the examples that both you and Tomas cited:
'ee' == 'street' # => false
'ee' == 'ee' # => true
"a\na" == 'a' # => false
"a\na" == "a\na" # => true