File "mbox_to_txt.py", line 172, in mailbox_text if author not in message['From']: TypeError: argument of type 'Header' is not iterable

[Wick-McLean]

Program returns this error:

Traceback (most recent call last):
File "mbox_to_txt.py", line 196, in
main()
File "mbox_to_txt.py", line 191, in main
for text in mailbox_text(mb, args.author):
File "mbox_to_txt.py", line 172, in mailbox_text
if author not in message['From']: