Iterate over a dictionary in Python

In this article, we will cover How to Iterate Through a Dictionary in Python. 

Dictionary in Python is a collection of data values, used to store data values like a map, unlike other Data Types that hold only a single value as an element, Dictionary holds the key: value pair. 

There are multiple ways to iterate over a dictionary in Python.

• Access key using the build .keys() 
• Access key without using a key() 
• Iterate through all values using .values()
• Iterate through all key, and value pairs using items()
• Access both key and value without using items()
• Print items in Key-Value in pair 

Note: In Python version 3.6 and earlier, dictionaries were unordered. But since Python version 3.7 and later, dictionaries are ordered.

Example 1: Access key using the build .keys() 

In this example, you will see that we are using an in-build. keys() method which helps us to print all the keys in the dictionary.

Output:

dict_keys(['Gujarat', 'Maharashtra', 'Rajasthan', 'Bihar'])

Example 2: Access key without using a key() 

Iterating over dictionaries using ‘for’ loops for iterating our keys and printing all the keys present in the Dictionary.

Output:

List Of given states:

Gujarat
Maharashtra
Rajasthan
Bihar

Time complexity: O(n), where n is the number of keys in the dictionary. 
Auxiliary space: O(1).

Example 3: Iterate through all values using .values()

In this example, we are using the values() method to print all the values present in the dictionary.

Output:

List Of given capitals:

Gandhinagar
Mumbai
Jaipur
Patna

Time complexity: O(n)
Auxiliary space: O(1)

Example 4: Iterate through all key, and value pairs using items()

In this example, we are printing all the key and value pairs present in a dictionary using a items() method.

List Of given states and their capitals:

Gujarat : Gandhinagar
Maharashtra : Mumbai
Rajasthan : Jaipur
Bihar : Patna

Example 5: Access both key and value without using items()

In this example, we are using a Python Loop Through a Dictionary, and with each iteration, we are obtaining the key of the directory after that, we are printing key data and we are using a key as an index to print values from the directory. 

Output:

Gujarat -> Gandhinagar
Maharashtra -> Mumbai
Rajasthan -> Jaipur
Bihar -> Patna

Example 6: Print items in Key-Value in pair 

In this example, we are printing the key values data in the form of pairs and all the pair are enclosed in a dictionary. 

Output:

dict_items([('Gujarat', 'Gandhinagar'), ('Maharashtra', 'Mumbai'), 
('Rajasthan', 'Jaipur'), ('Bihar', 'Patna')])

Example 7: Access key using unpacking of dict

In this example, you will see that we are using * to unpack the dict. The *dict method which helps us to unpack all the keys in the dictionary.

Output:

['Gujarat', 'Maharashtra', 'Rajasthan', 'Bihar']
Gandhinagar-Mumbai-Jaipur-Patna