import csv


def extract_pids_from_file(pid_file):
    """
    Extracts pids from file containing a header and pids in each line

    :param pid_file: path to the file containing the pids
    :return: list of ints
    """
    pids = []
    with open(pid_file, 'r') as f:
        csv_rows = csv.reader(f)
        next(csv_rows)
        for row in csv_rows:
            pids.append(int(row[0]))
    return pids