The xsv utility is a fast way to analyze
and work with CSV files from the command line.
With the search subcommand, I can seach for lines that match a pattern and
even narrow that search to focus on a selected column.
For instance, to search for any lines where column 3 is empty:
$ xsv search -s 3 '^$' data.csv
The -s 3 narrows the search to just column 3. The '^$' regex pattern
matches on cells where there is the start character (^) and end character
($) with nothing in between, hence empty.
I can then pipe that to wc -l to get a count of the number of empty lines.
$ xsv search -s 3 '^$' data.csv | wc -l
See xsv search --help for more details.