# Python >= 3.5:
def merge_dictionaries(a, b):
return {**a, **b}
# else:
def merge_dictionaries(a, b):
c = a.copy() # make a copy of a
c.update(b) # modify keys and values of a with the b ones
return c
a = { 'x': 1, 'y': 2}
b = { 'y': 3, 'z': 4}
print(merge_dictionaries(a, b)) # {'y': 3, 'x': 1, 'z': 4}# Example usage:
# Say you have the following dictionaries and want to merge dict_b into dict_a
dict_a = {"ABC": {"DE": {"F": "G"}}}
dict_b = {"ABC": {"DE": {"H": "I"}, "JKL": "M"}}
def merge_nested_dictionaries(dict_a, dict_b, path=None):
"""
recursive function for merging dict_b into dict_a
"""
if path is None:
path = []
for key in dict_b:
if key in dict_a:
if isinstance(dict_a[key], dict) and isinstance(dict_b[key], dict):
merge_nested_dictionaries(dict_a[key], dict_b[key], path + [str(key)])
# if the b dictionary matches the a dictionary from here on, skip adding it
elif dict_a[key] == dict_b[key]:
pass
# if the same series of keys lead to different terminal values in
# each dictionary, the dictionaries can't be merged unambiguously
else:
raise Exception('Conflict at %s' % '.'.join(path + [str(key)]))
# if the key isn't in a, add the rest of the b dictionary to a at this point
else:
dict_a[key] = dict_b[key]
return dict_a
# running:
merge_nested_dictionaries(dict_a, dict_b)
# returns:
{'ABC': {'DE': {'F': 'G', 'H': 'I'}, 'JKL': 'M'}}dict1 = {'color': 'blue', 'shape': 'square'}
dict2 = {'color': 'red', 'edges': 4}
dict1.update(dict2) #if a key exists in both, it takes the value of the second dict
# dict1 = {'color': 'red', 'shape': 'square', 'edges': 4}
# dict2 is left unchanged>>> x = {'a': 1, 'b': 2}
>>> y = {'b': 10, 'c': 11}
>>> z = {**x, **y} #In Python 3.5 or greater only
>>> print(z)
{'a': 1, 'b': 10, 'c': 11}
from collections import defaultdict
d1 = {1: 2, 3: 4}
d2 = {1: 6, 3: 7}
dd = defaultdict(list)
for d in (d1, d2): # you can list as many input dicts as you want here
for key, value in d.items():
dd[key].append(value)
print(dd)def mergeDict(dict1, dict2):
''' Merge dictionaries and keep values of common keys in list'''
dict3 = {**dict1, **dict2}
for key, value in dict3.items():
if key in dict1 and key in dict2:
dict3[key] = [value , dict1[key]]
return dict3
# Merge dictionaries and add values of common keys in a list
dict3 = mergeDict(dict1, dict2)
print('Dictionary 3 :')
print(dict3)