Check If Any Value Of A Dictionary Matches A Condition

How does a python programmer check if any value of a dictionary matches a condition (is greater than 0 in my case). I'm looking for the most 'pythonic' way that has minimal perform

Solution 1:

You can use any [docs]:

>>> pairs = { 'word1':0, 'word2':0, 'word3':2000, 'word4':64, 'word5':0, 'wordn':8 }
>>> any(v > 0 for v in pairs.itervalues())
True
>>> any(v > 3000 for v in pairs.itervalues())
False

See also all [docs]:

>>> all(v > 0 for v in pairs.itervalues())
False
>>> all(v < 3000 for v in pairs.itervalues())
True

Since you're using Python 2.7, .itervalues() is probably a little better than .values() because it doesn't create a new list.

Solution 2:

Python 3.x Update

In Python 3, direct iteration over mappings works the same way as it does in Python 2. There are no method based equivalents - the semantic equivalents of d.itervalues() and d.iteritems() in Python 3 are iter(d.values()) and iter(d.items()).

According to the docs, you should use iter(d.values()), instead of d.itervalues():

>>> pairs = { 'word1':0, 'word2':0, 'word3':2000, 'word4':64, 'word5':0, 'wordn':8 }
>>> any(v > 0 for v in iter(pairs.values()))
True
>>> any(v > 3000 for v in iter(pairs.values()))
False