How can I log my Python errors?
try:
do_something()
except:
# How can I log my exception here, complete with its traceback?
Uncaught exception messages go to STDERR, so instead of implementing your logging in Python itself you could send STDERR to a file using whatever shell you're using to run your Python script. In a Bash script, you can do this with output redirection, as described in the BASH guide.
Append errors to file, other output to the terminal:
./test.py 2>> mylog.log
Overwrite file with interleaved STDOUT and STDERR output:
./test.py &> mylog.log