Exporting only a specific set of pages in Python with aiohttp

In this guide, we'll show you how to export only a specific set of pages from a document using Python and the aiohttp library to convert them to PDF using PDFShift's API.

When you're converting a document, you might want to export only a specific set of pages from a document. This can be done by setting the pages parameter to the request.

It behaves exactly like the page parameter you can see when you print a document from your browser.

It accepts the following pattern:

A number, such as 2. This will print the page 2
A range, such as 2-4. This will print the pages 2 to 4 (2, 3 and 4)
A list, such as 2,4,5,9. This will print the pages 2, 4, 5 and 9

This way, you can only export the pages that you really need and get immediately the result you want in the PDF, without having to edit it.

Here's an example:

import aiohttp, asyncio, json, base64

# You can get an API key at https://pdfshift.io
api_key = 'sk_xxxxxxxxxxxx'

params = {
    'source': 'https://en.wikipedia.org/wiki/PDF',
    'pages': '2-4'
}

response = None
try:
    auth = base64.b64encode(
        'api:{}'.format(api_key).encode('utf-8')
    ).decode('utf-8')

    async with aiohttp.ClientSession() as session:
        async with session.post(
            'https://api.pdfshift.io/v3/convert/pdf',
            headers={'Authorization': f'Basic {auth}'},
            json=params
        ) as response:
            if response.status >= 400:
                raise Exception('Invalid request: {}'.format(await response.text()))

            with open('result.pdf', 'wb') as f:
                f.write(await response.read())

            print('The PDF document was generated and saved to result.pdf')
except asyncio.TimeoutError:
    raise Exception('The request took too long to process')
except aiohttp.ClientError as e:
    raise Exception(f'An error occurred: {e}')
except Exception as e:
    # We highly recommend you to handle exceptions. Often, PDFShift will provide you with a clear explanation about what happened.
    # Moreover, in case of error, no PDF are returned !
    raise Exception(f'An error occurred: {e}')

For further details on the pages property and its usage, please refer to our dedicated documentation.

We hope this guide was helpful. If you have any questions or noticed any issues on the code above,
feel free to drop us a line.