How pagination works
#APIs rarely return thousands of records in a single response — that would be slow and wasteful. Instead, they split results into pages. The /api/products/ endpoint returns up to 20 items per page by default, but the catalog has 372 products in total.
Every paginated response includes four top-level fields:
```python
data = response.json()
data['count'] # 372 — total items across ALL pages
data['next'] # URL of the next page, or null if this is the last page
data['previous'] # URL of the previous page, or null if this is the first
data['results'] # list of items on this page
```
To navigate pages, you have two options:
Option 1 — follow the next URL. The server builds the URL for you, so you never have to calculate page numbers:
```python
url = f'{BASE_URL}/api/products/'
while url:
data = requests.get(url).json()
for product in data['results']:
print(product['name'])
url = data['next'] # None when there are no more pages
```
Option 2 — calculate total pages and iterate with a counter:
```python
PAGE_SIZE = 20
first = requests.get(f'{BASE_URL}/api/products/', params={'page_size': PAGE_SIZE}).json()
total_pages = -(-first['count'] // PAGE_SIZE) # ceiling division
for page in range(1, total_pages + 1):
data = requests.get(
f'{BASE_URL}/api/products/',
params={'page': page, 'page_size': PAGE_SIZE},
).json()
# process data['results']
```
Following next is simpler and more robust — it works even if the total count changes while you are paginating. The counter approach is useful when you need to know how many pages there are upfront, for example to show a progress indicator.