How to Remove a Key from a Dictionary in Python

To remove a key from a dictionary in Python, use pop(key) to remove and return the value, or del dict[key] to delete the key without returning. Both methods remove the key and its value from the dictionary.

Syntax

There are two common ways to remove a key from a dictionary:

• dict.pop(key, default): Removes the key and returns its value. If the key is not found, returns default if provided, otherwise raises KeyError.
• del dict[key]: Deletes the key and its value. Raises KeyError if the key does not exist.

python

value = dict.pop(key, default)
del dict[key]

Example

This example shows how to remove a key using pop() and del. It also shows what happens if the key is missing.

python

my_dict = {'apple': 5, 'banana': 3, 'cherry': 7}

# Remove 'banana' using pop and get its value
banana_count = my_dict.pop('banana')
print('Removed banana count:', banana_count)
print('Dictionary after pop:', my_dict)

# Remove 'apple' using del
del my_dict['apple']
print('Dictionary after del:', my_dict)

# Using pop with default to avoid error
orange_count = my_dict.pop('orange', 0)
print('Removed orange count (default):', orange_count)

# Using del on missing key raises error
try:
    del my_dict['orange']
except KeyError:
    print('KeyError: orange not found')

Output

Removed banana count: 3
Dictionary after pop: {'apple': 5, 'cherry': 7}
Dictionary after del: {'cherry': 7}
Removed orange count (default): 0
KeyError: orange not found

Common Pitfalls

Trying to remove a key that does not exist without handling errors causes a KeyError. Using pop() without a default value or del on a missing key will raise this error.

Always provide a default value to pop() or use in to check if the key exists before deleting.

python

my_dict = {'a': 1, 'b': 2}

# Wrong: raises KeyError if key missing
# my_dict.pop('c')

# Right: provide default to avoid error
value = my_dict.pop('c', None)
print('Value:', value)  # prints None

# Wrong: raises KeyError if key missing
# del my_dict['c']

# Right: check before deleting
if 'c' in my_dict:
    del my_dict['c']
else:
    print('Key c not found, cannot delete')

Output

Value: None
Key c not found, cannot delete

Quick Reference

Summary of methods to remove keys from a dictionary:

Method	Description	Error if Key Missing?
pop(key)	Removes key and returns value	Yes, unless default provided
pop(key, default)	Removes key and returns value or default	No
del dict[key]	Deletes key and value	Yes
popitem()	Removes and returns last inserted key-value pair	Yes if dict empty

Key Takeaways

Use pop(key) to remove a key and get its value safely with a default.

Use del dict[key] to delete a key but check if it exists to avoid errors.

Providing a default to pop() prevents KeyError when key is missing.

Always handle missing keys to avoid runtime errors when removing keys.

Use popitem() to remove the last inserted key-value pair if needed.