This content originally appeared on DEV Community and was authored by matt swanson
A common question you may want to answer on user-input data is: what values have been entered and how many times is each one used?
Maybe you have a list of dropdown options and you want to investigate removing a rare-used option.
Ruby has two handy methods that I reach for often: uniq and tally.
Usage
The uniq method operates on an enumerable and compresses your data down to unique values.
Outreach::Task.all.map(&:status).uniq
=> ["Confirmed w/o Outreach",
"Awaiting Outreach",
"Responded",
"No Response Expected",
"Follow-up",
"Awaiting Reply"]
While most developers are familiar with uniq, the tally method is one of the best kept secrets in Ruby. The tally method takes an enumerable of values and returns a hash where the keys are unique values and the values are the number of times the value appeared in the list.
Outreach::Task.all.map(&:status).tally
=> {"Confirmed w/o Outreach"=>106,
"Awaiting Outreach"=>28,
"Responded"=>48,
"No Response Expected"=>10,
"Follow-up"=>4,
"Awaiting Reply"=>8}
These two methods are great to have in your toolbox to quickly explore your data in a Rails console.
Additional Resources
Ruby API: Enumerable#uniq
Ruby API: Enumerable#tally
This content originally appeared on DEV Community and was authored by matt swanson
matt swanson | Sciencx (2021-05-05T13:00:00+00:00) Quickly explore your data with `uniq` and `tally`. Retrieved from https://www.scien.cx/2021/05/05/quickly-explore-your-data-with-uniq-and-tally/
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