def main():
"""
Usage:
python3 app.py input.txt' or 'python3 < input.txt'
"""
log.info('Begin processing...')
t = process_time()
processor = Processor()
# Accept input from two types of sources:
# a filename passed in command line arguments or STDIN.
with open(sys.argv[1], 'r') if len(sys.argv) > 1 else sys.stdin as f:
for line in f:
processor.parse_event(line)
log.info('Finished processing in {0:.3f} seconds'.format(process_time() - t))
summary = processor.generate_summary()
processor.write_output(summary)
