# Example usage:
awk -F ' ' '{print $7}' input_file | sort | uniq -c
# Where:
# - awk returns the 7th tab-delimited column/field of the input_file
# - sort sorts the entries so that duplicate entries are adjacent
# - uniq -c returns the counts of each type of element
# Note:
# - add "| cut -c 9-" to remove the counts if you only want the unique values
# found in the column/field
# - the entrez-direct tool (conda install entrez-direct) has the command sort-uniq-count
# and sort-uniq-count-rank that do a better job of formatting the output