I have a bunch of code that looks similar to this:
try:
auth = page.ItemAttributes.Author
except:
try:
auth = page.ItemAttributes.Creator
except:
auth = None
Is there a nicer way to write out this logic? This makes my code really painful to read. I thought try..finally would work, but I assumed wrong
You can use hasattr to avoid the try/except blocks:
auth = None
for attrname in ['Author', 'Creator']:
if hasattr(page.ItemAttributes, attrname):
auth = getattr(page.ItemAttributes, attrname)
break
An alternate way to write the above is to use the else clause of a Python for loop:
for attrname in ['Author', 'Creator']:
if hasattr(page.ItemAttributes, attrname):
auth = getattr(page.ItemAttributes, attrname)
break
else:
auth = None
auth = None before the for loop to directly match the OPs original solution and avoid a NameError if nothing ends up matching.This makes my code really painful to read
Whatever you do, don't catch wildcards.
except: is the pythonic way to say: Hey, all exceptions are equal, I want every single error in my try block to end up here, I don't care if I catch an AttributeError or a WorldGotFuckedUpException. In your case, except AttributeError is much, much better AND easier to read.
This is just a side note. Mark's answer shows the best way to do it, IMHO.
@Mark Byers's answer is more flexible, but if you wanted a one-liner
auth = getattr(page.ItemAttributes, 'Author', None) or getattr(page.ItemAttributes, 'Creator', None)
page.ItemAttributes.Author could be None. The original code permits this case.