Python Dictionary Methods

What Are Dictionary Methods?

Dictionary methods are built-in functions in Python that help you access, modify, update, and manage dictionaries efficiently.

Commonly Used Dictionary Methods

MethodDescription
clear()Removes all items from the dictionary
copy()Returns a shallow copy of the dictionary
fromkeys()Creates a new dictionary from keys
get()Returns the value for a key
items()Returns a view object of key-value pairs
keys()Returns a view object of all keys
pop()Removes item by key and returns its value
popitem()Removes the last inserted key-value pair
setdefault()Returns value for key; inserts if missing
update()Updates the dictionary with another
values()Returns a view object of all values

Method Examples

1. clear()

person = {"name": "Alice", "age": 25}
person.clear()
print(person)

Output:

{}

2. copy()

person = {"name": "Bob", "age": 30}
new_person = person.copy()
print(new_person)

Output:

{'name': 'Bob', 'age': 30}

3. fromkeys()

keys = ["name", "age"]
default_dict = dict.fromkeys(keys, "unknown")
print(default_dict)

Output:

{'name': 'unknown', 'age': 'unknown'}

4. get()

person = {"name": "Charlie"}
print(person.get("name"))     # Existing key
print(person.get("age", 0))   # Missing key with default

Output:

Charlie
0

5. items()

person = {"name": "Dave", "age": 22}
print(person.items())

Output:

dict_items([('name', 'Dave'), ('age', 22)])

6. keys() and values()

person = {"name": "Dave", "age": 22}
print(person.keys())   # dict_keys(['name', 'age'])
print(person.values()) # dict_values(['Dave', 22])

7. pop()

person = {"name": "Dave", "age": 22}
age = person.pop("age")
print(age)        # 22
print(person)     # {'name': 'Dave'}

8. popitem()

person = {"name": "Dave", "age": 22}
last_item = person.popitem()
print(last_item)

Output:

('name', 'Dave')

9. setdefault()

person = {"name": "Eve"}
age = person.setdefault("age", 20)
print(person)  # {'name': 'Eve', 'age': 20}

10. update()

 

person = {"name": "Eve"}
person.update({"name": "Eva", "city": "Paris"})
print(person)

Output:

{'name': 'Eva', 'age': 20, 'city': 'Paris'}

Tips

  • Use get() when unsure if the key exists to avoid errors.
  • setdefault() is useful for setting default values during data cleaning.
  • update() is great for merging or adding multiple key-value pairs.

Conclusion

Python dictionaries come with powerful methods to manage data effectively. Learning these methods helps you write clean and efficient code.