When working with dictionaries in Python, it is common to append key-value pairs to an existing dictionary. However, this can sometimes result in the need to add more curly braces, which can be cumbersome and make the code less readable. In this article, we will explore three different ways to append key-value pairs to a dictionary without adding more curly braces.

Option 1: Using the update() method

The update() method in Python allows us to add multiple key-value pairs to a dictionary at once. We can use this method to append key-value pairs without adding more curly braces. Here’s an example:

my_dict = {'key1': 'value1'}
new_pairs = {'key2': 'value2', 'key3': 'value3'}

my_dict.update(new_pairs)

print(my_dict)

This will output:

{‘key1’: ‘value1’, ‘key2’: ‘value2’, ‘key3’: ‘value3’}

Option 2: Using the dictionary unpacking operator

In Python 3.5 and above, we can use the dictionary unpacking operator (**), also known as the double asterisk, to append key-value pairs to a dictionary. Here’s an example:

my_dict = {'key1': 'value1'}
new_pairs = {'key2': 'value2', 'key3': 'value3'}

my_dict = {**my_dict, **new_pairs}

print(my_dict)

This will output the same result as option 1:

{‘key1’: ‘value1’, ‘key2’: ‘value2’, ‘key3’: ‘value3’}

Option 3: Using the |= operator

In Python 3.9 and above, we can use the |= operator to update a dictionary with key-value pairs from another dictionary. This operator is known as the in-place union operator. Here’s an example:

my_dict = {'key1': 'value1'}
new_pairs = {'key2': 'value2', 'key3': 'value3'}

my_dict |= new_pairs

print(my_dict)

Once again, this will output the same result:

{‘key1’: ‘value1’, ‘key2’: ‘value2’, ‘key3’: ‘value3’}

After exploring these three options, it is clear that the best option depends on the version of Python you are using. If you are using Python 3.9 or above, option 3 using the |= operator is the most concise and efficient way to append key-value pairs to a dictionary. However, if you are using an older version of Python, options 1 and 2 are both viable alternatives.