If/then style question

[John Gordon]

(This is mostly a style question, and perhaps one that has already been
discussed elsewhere.  If so, a pointer to that discussion will be
appreciated!)

When I started learning Python, I wrote a lot of methods that looked like
this:


  def myMethod(self, arg1, arg2):

    if some_good_condition:

      if some_other_good_condition:

        if yet_another_good_condition:

          do_some_useful_stuff()
          exitCode = good1

        else:
          exitCode = bad3

      else:
        exitCode = bad2

    else:
      exitCode = bad1

    return exitCode


But lately I've been preferring this style:


  def myMethod(self, arg1, arg2):

    if some_bad_condition:
      return bad1

    elif some_other_bad_condition:
      return bad2

    elif yet_another_bad_condition:
      return bad3

    do_some_useful_stuff()
    return good1

I like this style more, mostly because it eliminates a lot of indentation.

However I recall one of my college CS courses stating that "one entry,
one exit" was a good way to write code, and this style has lots of exits.

Are there any concrete advantages of one style over the other?

Thanks.

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"