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

I believe that throwing an exception is a better idea for your situation. An alternative will be the simulation method to return a tuple. The first item will be the status and the second one the result:

result = simulate(open("myfile"))
if not result[0]:
  print "error parsing stream"
else:
  ret= result[1]