Python: Add a key to a dictionary

Last update on March 27 2025 12:57:48 (UTC/GMT +8 hours)

2. Add Key to Dictionary

Write a Python program to add a key to a dictionary.

Sample Solution:

Python Code:

# Create a dictionary 'd' with two key-value pairs.
d = {0: 10, 1: 20}

# Print the original dictionary 'd'.
print(d)

# Update the dictionary 'd' by adding a new key-value pair {2: 30}.
d.update({2: 30})

# Print the dictionary 'd' after the update, which now includes the new key-value pair.
print(d) 

Sample Output:

{0: 10, 1: 20}                                                                                                
{0: 10, 1: 20, 2: 30} 

For more Practice: Solve these Related Problems:

• Write a Python script to add a new key-value pair to a dictionary only if the key does not exist already.
• Write a Python script to update a dictionary with multiple new keys from a list, setting each to a default value.
• Write a Python script to merge a list of key-value pairs into an existing dictionary without overwriting existing keys.
• Write a Python script to insert a key into a dictionary at a specific position while preserving insertion order.

Python Code Editor:

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