Question

given a dict of items

sample = { 'a':1 , 'b':2 , 'c':3 , 'd':None , 'e':None }

i’d like to create a new dict that only has the items with a value.

this works..

a = dict([ i for i in testing.iteritems() if i[1]])

but i’m wondering if there’s something more pythonic/readable.

i was hoping i could do something like

a = dict([ i for i in testing.____() if i.value() ])

but there’s no standard iterator that works like that.

i’m just curious on this for readability purposes.

Answer 1

Use tuple unpacking (assigning each key and value to a separate variable, k and v in the following examples) and a dict comprehension:

a = {k: v for k, v in sample.iteritems() if v}

or test explicitly for None instead of all falsey values (numeric 0, empty sequences, etc.):

a = {k: v for k, v in sample.iteritems() if v is not None}

In Python 3, you need to use just items():

a = {k: v for k, v in sample.items() if v}

For your sample, all above variations result in:

>>> sample = { 'a':1 , 'b':2 , 'c':3 , 'd':None , 'e':None }
>>> {k: v for k, v in sample.iteritems() if v}
{'a': 1, 'c': 3, 'b': 2}