Removing entries from a dictionary based on values

Question

I have a dictionary with character-integer key-value pair. I want to remove all those key value pairs where the value is 0.

For example:

>>> hand {'a': 0, 'i': 0, 'm': 1, 'l': 1, 'q': 0, 'u': 0} 

I want to reduce the same dictionary to this:

>>> hand {'m': 1, 'l': 1} 

Is there an easy way to do that?

Answer 1

You can use a dict comprehension:

>>> { k:v for k, v in hand.items() if v } {'m': 1, 'l': 1} 

Or, in pre-2.7 Python, the dict constructor in combination with a generator expression:

>>> dict((k, v) for k, v in hand.iteritems() if v) {'m': 1, 'l': 1} 

Answer 2

hand = {k: v for k, v in hand.iteritems() if v != 0} 

For Pre-Python 2.7:

hand = dict((k, v) for k, v in hand.iteritems() if v != 0) 

In both cases you're filtering out the keys whose values are 0, and assigning hand to the new dictionary.