How to check values in dictionary with multiple data

How to check values in dictionary with multiple data

How to find a particular value if the dictionary contains more than one
set of data.
Example:
[{u'first_name': u'a, u'last_name': u'ab'}, { u'first_name': u'c',
u'last_name': u'cd',}]
This is the response i get when i do a get to a json.
I want to check that user "a" (first name) is the person who has "ab" as
last name.However the order of appearance will not always be the same.
I am writing this code in python/robot framework.
Can anyone help?