How do I extract all the values of a specific key from a list of dictionaries?

Question

I have a list of dictionaries that all have the same structure within the list. For example:

test_data = [{\'id\':1, \'value\':\'one\'}, {\'id\':2, \'value\         


        

Answer 1

If your data is truly large, a generator will be more efficient:

list((object['value'] for object in test_data))

ex:

>>> list((object['value'] for object in test_data))
['one', 'two', 'three']

The generator portion is this:

(object['value'] for object in test_data)

By wrapping that in a list(), you exhaust the generator and return its values nicely in an array.