Find Numeric Values in Ruby and then Convert them to Strings

Question

I have files that have a bunch of lines containing text and numbers. The text in each file stays the same, but the numbers change. (This is running data, so the lines are things like "- Active Duration 28:19, - Total distance 3.66mi.", etc.)

What I want to do is locate the individual numbers in these lines, then create my own output, such as: "Ran #{distance} in #{time}"

I'm able to locate these numbers in the lines using regular expressions, but I cannot figure out how to then take those values and make them into their own strings. I'm not even sure regex is the right approach. I've been running things like this:

if line =~/\d*\.\d*/
found completed = true

But then I'm not sure what comes next.

I hope I'm being clear—and thanks in advance for your help.

can you post an example string?

Casimir et Hippolyte
– Casimir et Hippolyte

2013-06-19 22:39:07 +00:00
Commented Jun 19, 2013 at 22:39 — Casimir et Hippolyte
– Casimir et Hippolyte, Commented Jun 19, 2013 at 22:39

BigLoppy · Accepted Answer · 2013-06-20 17:14:43Z

2

You can use regex in the element reference to get the number data. For example:

2.0.0-p0 :010 > distance = line[/\d*\.\d*/]
=> "3.66" 
2.0.0-p0 :011 > time = line[/\d*:\d*/]
 => "28:19" 
2.0.0-p0 :012 > puts "Ran #{distance} in #{time}"
Ran 3.66 in 28:19
 => nil

edited Jun 20, 2013 at 17:14

answered Jun 19, 2013 at 22:45

BigLoppy

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4 Comments

craigeley Over a year ago

That looks really promising. Does it require anything? Right now I'm getting 'undefined local variable or method `line' for main:Object (NameError)'

craigeley Over a year ago

Got it. Elegant and effective. Thanks!

Arie Xiao Over a year ago

I'd prefer line[/\d+\.\d*/], line[/\d+:\d+/] in scanning the only occurrence of a pattern.

BigLoppy Over a year ago

I like Arie's addition, that really smoothes things out.

Casimir et Hippolyte · Accepted Answer · 2013-06-19 23:15:40Z

1

You can do that:

rawlines = <<EOF
- Active Duration 28:19, - Total distance 3.66mi.
- Active Duration 25:12, - Total distance 3.66mi.
- Active Duration 24:10, - Total distance 3.66mi.
- Active Duration 28:21, - Total distance 3.66mi.
- Active Duration 27:19, - Total distance 3.66mi.
EOF

rawlines.scan(/Active Duration (\d++:\d++), - Total distance (\d++(?>\.\d++)?)/) do |dur, dist|
  puts "Ran #{dist} in #{dur}\n"
end

answered Jun 19, 2013 at 23:15

Casimir et Hippolyte

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Comments

Stephen · Accepted Answer · 2013-06-20 18:39:37Z

1

Updated answer to show iteration over file.

I put the results into a hash so that key-value pairs could be utilised for the manipulation of the data. New keys could be added for the unit of measurement, etc.

runData_20130620.txt
-Active Duration 09.87, -Total Distance 100.0m
-Active Duration 15:19, -Total Distance 4.98km
-Active Duration 03:00, -Total Distance 1.0mile
-Active Duration 21:14, -Total Distance 3.68, -Sweat Produced 5.99Gallons
-Active Duration 22:31, -Total Distance 3.65mi

Code

File.foreach("runData_20130620.txt") do |line|

    # Create hash, parsing string with regex pattern
    runData = Hash[*line.scan(/([^, \-]\D*) (\d*[.:]\d*)/).to_a.flatten]

    # This will convert the string keys to symbols, replacing white-space with 
    # underscores and downcasing

    runData = Hash[runData.map { |k,v|
                        [k.gsub(/\s+/, "_").downcase.to_sym, v] }] 

    # display results
    #runData.each { |k,v| puts "#{k} ** #{v}" }

    # display using hash symbol access...
    puts "\nRan a distance of #{ runData[:total_distance]} in
                                               runData[:active_duration]} "
    puts "Man, I am unfit!" if runData[:sweat_produced]
end

Results

Ran a distance of 100.0 in 09.87

Ran a distance of 4.98 in 15:19

Ran a distance of 1.0 in 03:00

Ran a distance of 3.68 in 21:14
Man, I am unfit!

Ran a distance of 3.65 in 22:31

edited Jun 20, 2013 at 18:39

answered Jun 20, 2013 at 2:48

Stephen

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5 Comments

Stephen Over a year ago

You would need to modify the regex patterns - I tidied the data slightly first

craigeley Over a year ago

Interesting—looks great! But how could I set this up as a script to read lines in a file? For example, "myData" is always changing, and I don't want to have to input it all by hand.

Stephen Over a year ago

That shouldn't be too difficult using regular constructs. Does your file have a specified format i.e. is every line in the file the same structure? @craigeley

craigeley Over a year ago

Each file contains lines such as: - Active Duration 28:19 - Total Distance 3.66 mi. etc. etc.

craigeley Over a year ago

There's always more than one way to skin a cat. Thanks!

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