summing up keys over two dictionaries

add_two_dict.py

d1 = {'key1': 50, 'key2': 100, 'key3':200}
d2 = {'key1': 200, 'key2': 100, 'key4':300}

# the concise way
from collections import Counter
new_dict = Counter(d1) + Counter(d2)
print(new_dict)

# the long way:
new_dict = {}

for j,u in d2.items():
    for k,v in d1.items():
        if j == k:
            new_dict[k] = u + v
        if k not in new_dict:
            new_dict[k] = v
        if j not in new_dict:
            new_dict[j] = u
            
print(new_dict)