Combine dictionaries with common and nonexistent keys without filling the gaps

Here is a list of dictionaries:

dictionaries = [    {"Key 1": "value1""Key 2": "value2""Key 3": "value3"    },    {"Key 1": "value4""Key 3": "value5""Key 4": "value6"    },    {"Key 1": "value7""Key 2": "value8""Key 4": "value9"    }]

Here are my expected results:

mergedDictionaries = {"Key 1": ["value1", "value4", "value7"],"Key 2": ["value2", "", "value8"],"Key 3": ["value3", "value5", ""],"Key 4": ["", "value6", "value9"]}

I tried using the collections module, but it fills up the gaps using this code below.

dictionary = defaultdict(list)for key in dictionaries:    for x, y in key.items():        dictionary[x].append(y)

The whole point of this is to make an accurate dataframe when combining the dictionaries.

Is there any method to recreate this situation?