Python Logging

For those of us that start a program with "print" statements to get our bearings, the Python logging library is a drop-in replacement. After creating the logger, you can replace "print" statements with logger.debug('same text as before') or use suitable levels from debug, info, warning, error, and critical. You quickly get logging that can be configured to different levels you can use from debugging during development and clear output for the program running. There's also a built-in handler on logging exceptions to cleanly log exception info during exception handling. The library and cookbook are both clear and illustrative so check these links out:

Python 3 Library - Logging

Python 3 Logging Cookbook

I mentioned shell logging last time here:

I'm a Logger and I'm Okay

The other tool I use all the time in Python is the "assert" call which raises an error with message given. For example to sanity check the resulting size of a blob is matching your file size:

# sanity check the resultant blob is the same size as what's in the database

assert (os.path.getsize(outpath) == len(imgblob)), "File size %d does not match blob size %d for image %d in %s saved to %s" % (os.path.getsize(outpath), len(imgblob), imgid, args.table, args.archivepath)

There's every opportunity to properly handle program output and errors.

Ciao

I'm a [logger] and I'm OK!

The "logger" command can send a text string to the syslog. #why-didn't-I-know-that-already

http://manpages.ubuntu.com/manpages/xenial/man1/logger.1.html

localadmin@mypc:~$ logger Mark

localadmin@mypc:~$ sudo tail /var/log/syslog
Oct 31 15:23:40 mypc systemd[16714]: Listening on GnuPG cryptographic agent and passphrase cache (restricted).
Oct 31 15:23:40 mypc systemd[16714]: Reached target Timers.
Oct 31 15:23:40 mypc systemd[16714]: Listening on GnuPG network certificate management daemon.
Oct 31 15:23:40 mypc systemd[16714]: Listening on D-Bus User Message Bus Socket.
Oct 31 15:23:40 mypc systemd[16714]: Reached target Sockets.
Oct 31 15:23:40 mypc systemd[16714]: Reached target Basic System.
Oct 31 15:23:40 mypc systemd[16714]: Reached target Default.
Oct 31 15:23:40 mypc systemd[16714]: Startup finished in 44ms.
Oct 31 15:23:40 mypc systemd[1]: Started User Manager for UID 1000.
Oct 31 15:23:46 mypc localadmin: Mark 

In other news I updated my page on useful PC tools

• https://archangel.thenibble.org/p/essential-plugins.html  

Ciao