Combine Or Merge Dictionaries Based On More Than One Key Or Multi Keys

I've been searching all morning but most examples of merging was based on only one key, I couldn't find anything on multiple keys. x = [ {'pid':111, 'sid':6, 'eid':123, 'x_qty'

Solution 1:

This is re-keying off a tuple:

>>> from operator import itemgetter
>>> from collections import defaultdict
>>> data = defaultdict(dict)
>>> f = itemgetter('pid', 'sid', 'eid')
>>> for d in [*x, *y]:
...     data[f(d)].update(d)
... >>> list(data.values())
[{'eid': 123, 'pid': 111, 'sid': 6, 'x_qty': 30, 'y_qty': 123},
 {'eid': 6212, 'pid': 222, 'sid': 56, 'x_qty': 2},
 {'eid': 6212, 'pid': 333, 'sid': 56, 'y_qty': 112}]

Solution 2:

Here is an alternative using 3rd party library pandas, which accepts a list of dictionaries.

import pandas as pd

# merge data
merged = pd.DataFrame(x).merge(pd.DataFrame(y), how='outer')

# iterate, remove nan, convert to int
res = [s.dropna().astype(int).to_dict() for _, s in merged.iterrows()]

[{'eid': 123, 'pid': 111, 'sid': 6, 'x_qty': 30, 'y_qty': 123},
 {'eid': 6212, 'pid': 222, 'sid': 56, 'x_qty': 2},
 {'eid': 6212, 'pid': 333, 'sid': 56, 'y_qty': 112}]