Sometimes I find myself doing tedious things like trying to grab the dollar amounts from text copied from the web. More and more often I turn to irb for these sort of things. For example, a few minutes ago, when I wanted to analyze my spending habits I copied the data into a file and manipulated it.
I grabbed the lines from the file
irb(main):001:0> lines = File.readlines 'transactions'
…
And selected those with dollar signs (with a little effort–sometimes I forget whether it is =~ or ~=).
irb(main):002:0> monies = lines.select {|l| l ~= /\$(.*)/}
SyntaxError: compile error
(irb):2: syntax error, unexpected '='
monies = lines.select {|l| l ~= /\$(.*)/}
^
from (irb):2
from :0
irb(main):003:0> monies = lines.select {|l| l =~ /\$(.*)/}
Then I grabbed the numbers using map.
irb(main):008:0> nums =monies.map {|m| m.sub( /\$(.*)/,$1).to_f}
From there, I could do all sorts of things.
I could sum numbers.
total =nums.inject(0){|sum,i|sum+i}
I could get the average.
total/nums.length
I could even see how much of the total was due to transactions under $20.
nums.reject {|i|i>20}.inject{|s,i|s+i}
In short, I like ruby.