Looping Through Dictionaries

tags: #python/documentation/dictionaries

There are three ways to iterate over the items in a dictionary by using a For Loop based on its:

• Keys
• Values
• Key-Value Pair

1. Looping Through all Key-Value Pairs

Python dictionary provides a method called items() that returns an object which contains a list of key-value pairs as tuples in a list. To iterate over all key-value pairs in a dictionary, you can use a for loop to unpack each tuple in the list.

Example:

person = {
    'first_name': 'John',
    'last_name': 'Doe',
    'age': 25,
    'favorite_colors': ['blue', 'green'],
    'active': True
}

for key, value in person.items():
    print(f"{key}: {value}") # f string

first_name: John
last_name: Doe
age: 25
favorite_colors: ['blue', 'green']
active: True

2. Looping through all the keys in a dictionary

You can loop through keys in a dictionary by using a for loop with the keys() method.

for key in dictionary.keys():
	print(key)

Note: looping through all keys is the default behaviour when looping through a dictionary -> therefore, a keys() method is not necessary:

for key in dictionary_name:
	print(key)

3. Looping through all the values in a dictionary

You can loop through values in a dictionary by using a for loop with the values() method.

for value in dictionary.values():
	print(value)