How to filter a dictionary in Python?

Question

d = {'foo': 'x',
     'bar': 'y',
     'zoo': 'None',
     'foobar': 'None'}

I want to filter all the items whose value is 'None' and update the foo and bar items with a particular value. I tried:

for i in x.items():
   ....:    if i[i] == 'None':
   ....:        x.pop(i[0])
   ....:    else:
   ....:        x.update({i[0]:'updated'}) 

But it is not working.

Answer 1

It is not clear what is 'None' in the dictionary you posted. If it is a string, you can use the following:

dict((k, 'updated') for k, v in d.iteritems() if v != 'None')

If it is None, just replace the checking, for example:

dict((k, 'updated') for k, v in d.iteritems() if v is None)

Answer 2

it's not clear where you're getting your 'updated' value from, but in general it would look like this:

{i: 'updated' for i, j in d.items() if j != 'None'}

in python2.7 or newer.