YAML List of Maps
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A YAML list of maps is a useful data structure that allows you to store a collection of related information in a clear and easy-to-read format.
In this guide, we'll explain how to create and work with a YAML list of maps.
What is a YAML List of Maps?
A YAML list of maps is a collection of key-value pairs, where each key-value pair is defined as a map, and the collection of maps is defined as a list.
The YAML format uses whitespace to define the hierarchy of the maps and the elements within the maps.
For example, a YAML list of maps could look like this:
- name: Alice
age: 25
address:
street: 123 Main St
city: Anytown
state: CA
- name: Bob
age: 30
address:
street: 456 Oak Ave
city: Othertown
state: NY
In this example, the list contains two maps, one for Alice and one for Bob.
Each map has keys for name, age, and address, with the address key having its own map for the street, city, and state keys.
Creating a YAML List of Maps
To create a YAML list of maps, you'll need to use a text editor or IDE that supports YAML syntax.
You can start by defining the list with a hyphen -
followed by a space, and then add the maps with key-value pairs.
For example, to create a list of two people with their names and ages, you could use the following YAML code:
- name: Alice
age: 25
- name: Bob
age: 30
You can also nest maps within other maps by indenting the keys and values.
For example, to include the address information for each person, you could modify the previous example to look like this:
- name: Alice
age: 25
address:
street: 123 Main St
city: Anytown
state: CA
- name: Bob
age: 30
address:
street: 456 Oak Ave
city: Othertown
state: NY
Accessing and Manipulating a YAML List of Maps
Once you've created a YAML list of maps, you can access and manipulate the data using a YAML parser or a programming language that supports YAML.
For example, if you're working with Python, you can use the PyYAML library to load the YAML data into a Python object, like this:
import yaml
with open('people.yaml', 'r') as file:
people = yaml.load(file, Loader=yaml.FullLoader)
print(people[0]['name']) # Output: Alice
This code opens a YAML file named 'people.yaml', loads the data into a Python object, and then prints the name of the first person in the list.
You can also modify the data by updating the key-value pairs or adding new maps to the list.
For example, to add a new person to the list, you could use the following code:
new_person = {'name': 'Charlie', 'age': 40}
people.append(new_person)
with open('people.yaml', 'w') as file:
yaml.dump(people, file)
This code creates a new map for Charlie, appends it to the list, and then saves the updated list back to the YAML file.
Conclusion
A YAML list of maps is a powerful data structure that can be used to store and organize complex data in a clear and easy-to-read format.