Updating a list of python dictionaries with a key, value pair from another list

Question

Let's say I have the following list of python dictionary:

dict1 = [{'domain':'Ratios'},{'domain':'Geometry'}]

and a list like:

list1 = [3, 6]

I'd like to update dict1 or create another list as follows:

dict1 = [{'domain':'Ratios', 'count':3}, {'domain':'Geometry', 'count':6}]

How would I do this?

Answer 1

>>> l1 = [{'domain':'Ratios'},{'domain':'Geometry'}]
>>> l2 = [3, 6]
>>> for d,num in zip(l1,l2):
        d['count'] = num


>>> l1
[{'count': 3, 'domain': 'Ratios'}, {'count': 6, 'domain': 'Geometry'}]

Another way of doing it, this time with a list comprehension which does not mutate the original:

>>> [dict(d, count=n) for d, n in zip(l1, l2)]
[{'count': 3, 'domain': 'Ratios'}, {'count': 6, 'domain': 'Geometry'}]

Answer 2

You could do this:

for i, d in enumerate(dict1):
    d['count'] = list1[i]