Is there a more pythonic way to do this dictionary iteration?

I have a dictionary in the view layer, that I am passing to my templates. The dictionary values are (mostly) lists, although a few scalars also reside in the dictionary. The lists if present are initialized to None.

The None values are being printed as 'None' in the template, so I wrote this little function to clean out the Nones before passing the dictionary of lists to the template. Since I am new to Python, I am wondering if there could be a more开发者_如何学JAVA pythonic way of doing this?

# Clean the table up and turn Nones into ''

for k, v in table.items():
#debug_str = 'key: %s, value: %s' % (k,v)
#logging.debug(debug_str)

try:
    for i, val in enumerate(v):
        if val == None: v[i] = ''

except TypeError:
    continue;

Have you looked at defaultdict within collections? You'd have a dictionary formed via

defaultdict(list)

which initializes an empty list when a key is queried and that key does not exist.

filtered_dict = dict((k, v) for k, v in table.items() if v is not None)

or in Python 2.7+, use the dictionary comprehension syntax:

filtered_dict = {k: v for k, v in table.items() if v is not None}