In Python how should I test if a variable is None, True or False

Question

I have a function that can return one of three things:

• success (True)
• failure (False)
• error reading/parsing stream

Answer 1

Don't fear the Exception! Having your program just log and continue is as easy as:

try:
    result = simulate(open("myfile"))
except SimulationException as sim_exc:
    print "error parsing stream", sim_exc
else:
    if result:
        print "result pass"
    else:
        print "result fail"

# execution continues from here, regardless of exception or not

And now you can have a much richer type of notification from the simulate method as to what exactly went wrong, in case you find error/no-error not to be informative enough.