Question

I have something like this using BeautifulSoup:

for line in lines:
    code = l.find('span', {'class':'boldHeader'}).text
    coded = l.find('div', {'class':'Description'}).text
    definition = l.find('ul', {'class':'definitions'}).text
    print code, coded, def

However, not all elements exist at all times. I can enclose this in a try except so that it does not break the program execution like this:

for line in lines:
    try:
      code = l.find('span', {'class':'boldHeader'}).text
      coded = l.find('div', {'class':'Description'}).text
      definition = l.find('ul', {'class':'definitions'}).text
      print code, coded, def
    except:
      pass

But how I execute the statements in a greedy fashion? For instance, if there are only two elements available code and coded, I just want to get those and continue with the execution. As of now, even if code and coded exist, if def does not exist, the print command is never executed.

One way of doing this is to put a try...except for every statement like this:

for line in lines:
    try:
      code = l.find('span', {'class':'boldHeader'}).text
    except:
      pass
    try:
      coded = l.find('div', {'class':'Description'}).text
    except:
      pass
    try:
      definition = l.find('ul', {'class':'definitions'}).text
    except:
      pass
    print code, coded, def

But this is an ugly approach and I want something cleaner. Any suggestions?

Answer 1

How about capture the “ugly” code in a function, and just call the function as needed:

def get_txt(l,tag,classname):
    try:
        txt=l.find(tag, {'class':classname}).text
    except AttributeError:
        txt=None
    return txt

for line in lines:
    code = get_txt(l,'span','boldHeader')
    coded = get_txt(l,'div','Description')
    defn = get_txt(l,'ul','definitions')
    print code, coded, defn

PS. I changed def to defn because def is a Python keyword. Using it as a variable name raises a SyntaxError.

PPS. It’s not a good practice to use bare exceptions:

try:
    ....
except:
    ...

because it almost always captures more that you intend. Much better to be explicit about what you want to catch:

try:
    ...
except AttributeError as err:
    ...