psql is an excellent command line tool, but lacks the advanced report formatting facilities of, for example, Oracle's SQL*Plus. However it can be used to output results in several different formats including CSV.

To generate a comma-separated file (CSV), set the following format options:

\pset tuples_only
\pset format unaligned
\pset fieldsep ,
\pset recordsep '\n'

The results of any statements now issued will be in CSV format. To output text fields correctly, ensure they are wrapped in quotes, e.g.:

SELECT '"' || text_field  || '"' AS text_field,
       sum
  FROM report_view

To return to the usual output format it's probably easier to start a new psql session.