Checking for attributes in BeautifulSoup?

Question

I'm parsing some data from HTML by walking through elements at a certain level using nextSibling, and doing different things depending on the tag name and class of each element encountered.

e.g.,

if n.name == "p" and n.class == "poem": blah()

But this raises an error if the element doesn't have a class or if it isn't an instance of Tag and hence has no name.

Testing before accessing like this

if "name" in n:

always return false. I could check the type of the object returned by nextSibling to try to weed out NavigableString and Comment, but there's got to be an easier way.

EDIT

Emailed the dev of BeautifulSoup with this question and he recommended testing with

n.get("class")

which returns None if "class" is unset, which makes it possible to just do:

if n.get("class") == "poem": blah()

Answer 1

Besides using get() method

n.get("class")

Another option is to use has_attr() (use has_key() pre BeautifulSoup 4):

n.has_attr("class")

Answer 2

In this case exceptions may be your friend:

try:
    if n.name == 'p' and n['class'] == "poem":
        blah()
except AttributeError: # element does not have .name attribute
    do_something()
except KeyError: # element does not have a class
    do_something_else()

You may also wrap it into one except if this is in case:

try:
    if n.name == 'p' and n['class'] == "poem":
        blah()
except (AttributeError, KeyError):
    pass