Python: Check if one dictionary is a subset of another larger dictionary

In Python 3, you can use dict.items() to get a set-like view of the dict items. You can then use the <= operator to test if one view is a "subset" of the other:

d1.items() <= d2.items()

In Python 2.7, use the dict.viewitems() to do the same:

d1.viewitems() <= d2.viewitems()

In Python 2.6 and below you will need a different solution, such as using all():

all(key in d2 and d2[key] == d1[key] for key in d1)

Convert to item pairs and check for containment.

all(item in superset.items() for item in subset.items())

Optimization is left as an exercise for the reader.

Note for people that need this for unit testing: there's also an assertDictContainsSubset() method in Python's TestCase class.

http://docs.python.org/2/library/unittest.html?highlight=assertdictcontainssubset#unittest.TestCase.assertDictContainsSubset

It's however deprecated in 3.2, not sure why, maybe there's a replacement for it.