Python Program to Merge Two Dictionaries

Example 1: Using the | Operator

dict_1 = {1: 'a', 2: 'b'}
dict_2 = {2: 'c', 4: 'd'}

print(dict_1 | dict_2)

Output

{1: 'a', 2: 'c', 4: 'd'}

In Python 3.9 and later versions, the | operator can be used to merge dictionaries.

Note: If there are two keys with the same name, the merged dictionary contains the value of the latter key.

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Example 2: Using the ** Operator

dict_1 = {1: 'a', 2: 'b'}
dict_2 = {2: 'c', 4: 'd'}

print({**dict_1, **dict_2})

Output

{1: 'a', 2: 'c', 4: 'd'}

In the above program, we have used ** to unpack dictionaries dict_1 and dict_2. Then, the dictionaries are merged by placing them inside {}.

To know more about **kwargs, visit Python *args and **kwargs.

Note: The above code works for Python 3.5 and above versions.

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Example 3: Using copy() and update()

dict_1 = {1: 'a', 2: 'b'}
dict_2 = {2: 'c', 4: 'd'}

dict_3 = dict_2.copy()
dict_3.update(dict_1)

print(dict_3)

Output

{2: 'b', 4: 'd', 1: 'a'}

Here, we have first copied the elements of dict_2 to dict_3 using the dictionary copy() method. Then, we updated dict_3 with the values of dict_1 using the dictionary update() method.