def print_usage():
    """Print a help message."""
    print(
        """query_pubmed.py [-h] [-c] [-d delay] query

This script sends a query to PubMed (via the NCBI Entrez webservice*)
and prints the MEDLINE formatted results to the screen.

Arguments:
    -h           Print out this help message.
    -c           Count the hits, and don't print them out.

* http://www.ncbi.nlm.nih.gov/Entrez/
"""
        )
