Dictionaries in list: conditional update with .update()

I am trying to update dictionaries in a list nodes with tuples in another list source with a conditional.

Tuple list:

source = [('144 IV 285', 16),
 ('144 IV 1', 11),
 ('141 IV 155', 7)]

Dictionary list:

nodes = [{'id': '144 IV 285','date': '2018-08-15','relevancy': 10, 'outDegree': 18},
{'id': '144 IV 240','date': '2016-08-15','relevancy': 4, 'outDegree': 10}]

Each item in 'nodes' should be extended by a new key (inDegree) value pair based on the 'source' list. My code:

for item in sources:
    for item2 in nodes:
        if item2["id"] == item[0]:
            item2.update( {"inDegree": item[1]})
        else:
            item2.update( {"inDegree": 0})

Problem: How can I populate the key inDegree either by the value in the source list or 0, if there is no matching id for an item in 'nodes' in the 'source' list?