Error in screen name

[yemen2016]

I got this error:

usage: twitter_scraper.py [-h] [--since SINCE] [--until UNTIL]
[--exclude-retweets] [--delta-days DELTA_DAYS]
[--wait-secs WAIT_SECS] [--debug]
screen_name
twitter_scraper.py: error: the following arguments are required: screen_name

please help me...

[justinlittman]

You should invoke with a command like: python twitter_scraper.py @realDonaldTrump.