How to check if a key-value pair is present in a dictionary?

Question

Is there a smart pythonic way to check if there is an item (key,value) in a dict?

a={\'a\':1,\'b\':2,\'c\':3}
b={\'a\':1}
c={\'a\':2}

b in a:
--> True
c          


        

Answer 1

>>> a = {'a': 1, 'b': 2, 'c': 3}
>>> b = {'a': 1}
>>> c = {'a': 2}

First here is a way that works for Python2 and Python3

>>> all(k in a and a[k] == b[k] for k in b)
True
>>> all(k in a and a[k] == c[k] for k in c)
False

In Python3 you can also use

>>> b.items() <= a.items()
True
>>> c.items() <= a.items()
False

For Python2, the equivalent is

>>> b.viewitems() <= a.viewitems()
True
>>> c.viewitems() <= a.viewitems()
False