You need to say:
string.split(',',-1)
to avoid omitting the trailing blanks.
per Why does Ruby String#split not treat consecutive trailing delimiters as separate entities?
The second parameter is the "limit" parameter, documented at http://ruby-doc.org/core-2.0.0/String.html#method-i-split as follows:
If the "limit" parameter is omitted, trailing null fields are
suppressed. If limit is a positive number, at most that number of
fields will be returned (if limit is 1, the entire string is returned
as the only entry in an array). If negative, there is no limit to the
number of fields returned, and trailing null fields are not
suppressed.
