PYTHON
Efficiently Merge Multiple Dictionaries
Combine two or more Python dictionaries into a single dictionary using modern syntax, handling key collisions and preserving data efficiently.
dict1 = {'a': 1, 'b': 2}
dict2 = {'b': 3, 'c': 4}
dict3 = {'d': 5, 'a': 6}
# Python 3.9+ using the union operator (|)
# The rightmost dictionary's value takes precedence for duplicate keys.
merged_dict_39 = dict1 | dict2 | dict3
print(f"Merged (Python 3.9+): {merged_dict_39}")
# Python 3.5+ using dictionary unpacking (**)
# The order of unpacking matters for duplicate keys.
merged_dict_35 = {**dict1, **dict2, **dict3}
print(f"Merged (Python 3.5+): {merged_dict_35}")
# Alternative for older Python versions or explicit iteration
# Create a new dictionary and update sequentially
merged_dict_manual = {}
merged_dict_manual.update(dict1)
merged_dict_manual.update(dict2)
merged_dict_manual.update(dict3)
print(f"Merged (Manual Update): {merged_dict_manual}")
How it works: Merging dictionaries is a common task. Python 3.9 introduced the `|` union operator, providing a clean and direct way to combine dictionaries, with values from the rightmost dictionary overriding those from the left in case of key collisions. For Python 3.5 and later, dictionary unpacking (`**`) offers a similar approach. Older versions require sequential `update()` calls or manual iteration. Both `|` and `**` are concise and efficient methods for merging.