Python efficient exception handling

Question

I'm trying to figure out if there's a more pythonic way to do a specific error handling task. I want to catch multiple specific custom exceptions and do something specific depending on which exception is caught (like use a specific custom exit code, or add a specific log message, etc...). However, I also want, if any exception is raised, to do send an email saying the script didn't complete successfully, had exit code __, the log is at C:\foo\bar.txt

I know I could include everything I want to do in each except, such as:

try:
    do_something()
except CustomError1:
    exitcode = 1
    send_error_email(exitcode)
    sys.exit(exitcode)
except CustomError2:
    exitcode = 2
    send_error_email(exitcode)
    sys.exit(exitcode)

But I'm wondering if there's a more pythonic or more efficient way of doing it. I'm imagining something like

try:
    do_something()
except CustomError1:
    exitcode = 1
except CustomError2:
    exitcode = 2
except ParrentCustomErrorClass:
    send_error_email()
    sys.exit(exitcode)

If it matters, I'm currently stuck with python 2.7, but need to be able to port solution to 3.x when 3rd party applications allow it.

Answer 1

Two idioms I have seen are:

With finally

exit_code = None
try:
   do_something()
except CustomError1:
    exit_code = 1
except CustomError2:
    exit_code = 2
finally:
    if exit_code is not None:
        send_error_mail(exit_code)

With "dictionary dispatch"

try:
    do_something()
except Exception as e:
    code = {
        CustomError1: 1
        CustomError2: 2
    }.get(type(e))
    if code is None:
        raise
    send_error_email(code)

(or if you wanna go full PEP572),

    ...
    if (code := {
        CustomError1: 1
        CustomError2: 2
    }.get(type(e))) is not None:
         send_error_email(code)
    raise

---

If you control your exceptions however (and they are not library exceptions) - I do like @scnerd's solution too. If you don't - and want to catch ValueErrors or TypeErrors or whatever then one of these is the way to go.