Question

Here is what I try to do and I use windows and Python 3.3

LOG_FILENAME = 'log_trial_%s.txt' % datetime.datetime.now().strftime('%m%d-%H:%M:%S')
log_fd = open(LOG_FILENAME, 'w')
log_fd.write('===================\n')

The above codes are of course a part of a module and whe I ran the module, I got an error message as follows:

log_fd = open(LOG_FILENAME, 'w')
OSError: [Errno 22] Invalid argument: 'log_trial_1209-11:39:40.txt'

I have no idea what the long weird log finame means (‘log_trial_%s.txt’ …) and how to fix the error thing as well.

I will appreciate your time and help.

Answer 1

Windows file names can’t have colons in them.

Try this instead:

LOG_FILENAME = 'log_trial_%s.txt' % datetime.datetime.now().strftime('%m%d-%H%M%S')