In Python, a “List” represents a collection of ordered items that are mutable/changeable. On the other hand, a dictionary is a data structure that holds the collection of elements as key-value pairs. Lists are written with square brackets, dictionaries are written with curly braces, and commas separate the items. Keys and values in a dictionary can be of any type. In Python, a list of dictionaries is a collection of dictionaries where each dictionary represents a single entity, and the list represents a collection of entities.

How to Create/Define a List of Dictionaries?

Python allows us to create a list who’s each item represents a dictionary, and this type of list is referred to as a list of dictionaries. Syntax: To create a list of dictionaries in Python, you can use the following syntax:

list_of_dicts = [{'key_1': item_1, 'key_2': item_2, ..., 'key_n': item_n}, {'key_1': item_1, 'key_2': item_2, ..., 'key_n': item_n}, ...]

Let’s comprehend it practically.

Example: Creating a List of Dictionary for Employees’ Data

This example will teach you how to define a list of dictionaries in Python. This example program creates a list of dictionaries for the employee’s data.

emp_info = [{1: 'John', 2: 'Sasha', 3: 'Boby'},
             {1: 'Alexa', 2: 'Stephan', 3: 'Naomi', 4: 'Jacky'}]
print(emp_info)

The employee id is defined as a key, while the employee name is defined as a value. Output:

In the above image, two dictionary-type items are created in the “emp_info” list.

How to Access Keys Using Indexes?

To access the keys in a list of dictionaries using indexes, you can use the following syntax:

list_of_dict[index][key]

Here is an example of how you can do this.

Example: Accessing Dictionary’s Keys Using Indexes

In this example, some specific keys will be accessed using the indexes:

emp_info = [{1: 'John', 2: 'Sasha', 3: 'Boby'},
             {1: 'Alexa', 2: 'Stephan', 3: 'Naomi', 4: 'Jacky'}]
print(emp_info[0][2])
print(emp_info[1][3])

Output:

In the above image the second element of the first dictionary and third element of the second dictionary are accessed using the respective indexes.

How to Add/Append a New Dictionary to a List of Dictionaries?

Python’s append() function adds/appends a new dictionary to an already existing list of dictionaries. Syntax: The following syntax is used to append a new dictionary:

list.append(new_dictionary)

Note: When you append a dictionary to a list, the dictionary is not copied. Instead, a reference to the same dictionary object is added to the list. So, changing the original dictionary will also affect the list.

Example: Python Code to Append a New Dictionary to a List of Dictionaries

In this example, a new dictionary “new_emp” will be created and appended with an existing list of dictionaries “emp_info”:

emp_info = [{1: 'John', 2: 'Sasha', 3: 'Boby'},
             {1: 'Alexa', 2: 'Stephan', 3: 'Naomi', 4: 'Jacky'}]
new_emp = {1: 'Jones', 2: 'Trish'}
emp_info.append(new_emp)
print(emp_info)

Output

The “new_emp” dictionary is appended to the “emp_info” list of dictionaries.

How to Delete/Remove a Specific Dictionary From a List of Dictionaries?

In Python, you can delete a particular dictionary using the Del keyword. Syntax The following syntax is used to delete a dictionary from a list of dictionaries:

del list_of_dicts[index][key]

Here is an example of how to use the del keyword to delete a dictionary from a list.

Example: Deleting a Dictionary From a List of Dictionaries

Suppose you need to delete the second key of the second dictionary. For this, you can use the del keyword as follows:

emp_info = [{1: 'John', 2: 'Sasha', 3: 'Boby'},
             {1: 'Alexa', 2: 'Stephan', 3: 'Naomi', 4: 'Jacky'}]
del emp_info[1][2]
print(emp_info)

Output:

The second key of the second dictionary is deleted successfully.

Conclusion

A list of dictionaries is a data structure in which each list element is a dictionary. This can be useful for storing and organizing data that has multiple attributes or properties associated with each item. In this post, we have learned different use cases of the List of dictionaries using examples.