Alright, let's begin by looking at the code and breaking it down step by step.
import requests
import json
def retrieve_and_display_data(url):
response = requests.get(url)
data = response.json()
for item in data['results']:
print(item['name'])
if data.get('next'):
retrieve_and_display_data(data['next'])
retrieve_and_display_data("https://swapi.co/api/people/")
The code here is a bit messy since the function is doing too many things - fetching the data, processing it, checking for more pages, and printing the results all within one function. It's not ideal, but for this example, it works.
So why use a function in the first place?
We need to repeat the same actions (fetch, process, and display data) multiple times, once per page. The only thing that changes each time is the URL for the next page. Hence, we pass the URL as an argument to the function.
The following lines are pretty straightforward if you're already familiar with them.
Then comes the crucial line: if data.get('next'):
In dictionaries, you usually access values using dictionary[key], which raises a KeyError if the key doesn't exist. Using .get('key') instead checks if the key exists without raising an exception. While the try/except method is considered more "pythonic", the if statement might be easier to grasp.
What does .get('next') do? Essentially the same thing, but it returns None if the key is missing. In Python, None evaluates to false.
In essence, this line checks if the 'next' key is present in your data (the API returns null for missing data). If it's there, we call the function again with the URL of the next page, continuing until the 'next' key is absent or null in the JSON response.
Simply kick off the function with the initial URL and let it handle the rest :)
I hope this explanation clarifies everything for you!