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How to Generate PDF Invoices from HTML in Python

In this post, you’ll learn how to generate PDF invoices from HTML using our Python PDF Generator API. With our API, you receive 100 credits with the free plan. Different operations on a document consume different amounts of credits, so the number of PDF documents you can generate may vary. To access your API key, sign up for a free account.

To help you get started, we’ve provided a free invoice template in HTML and CSS that can be customized to meet your specific requirements. You can easily style your invoices by updating the CSS file with your own custom images and fonts.

If your invoices are longer than one page, you can add a header and footer section to your HTML file that repeats across all your pages. This ensures that the information you typically add to the top and bottom of your invoices (like the address, logo, page numbers, etc.) is displayed across all the pages.

Requirements

To get started, you’ll need:

To access your PSPDFKit API key, sign up for a free account. Your account includes 100 credits, which can be used for various document operations. Once you’ve signed up, you can find your API key in the Dashboard > API Keys section.

Python is a programming language, and pip is a package manager for Python, which you’ll use to install the requests library. Requests is an HTTP library that makes it easy to make HTTP requests.

Install the requests library with the following command:

python -m pip install requests

Setup

Download the invoice template and extract the contents of the ZIP file into a folder. You’ll get an HTML file, Inter fonts, a Space Mono font, an SVG logo, and a README file.

Creating a CSS File

If you open the index.html file, you’ll see the styles between the opening and closing <style> tag. Copy the styles to a new file called style.css, and save it in the same folder:

@font-face {
	font-family: 'Inter';
	src: url('Inter-Regular.ttf') format('truetype');
	font-weight: 400;
	font-style: normal;
}

@font-face {
	font-family: 'Inter';
	src: url('Inter-Medium.ttf') format('truetype');
	font-weight: 500;
	font-style: normal;
}

@font-face {
	font-family: 'Inter';
	src: url('Inter-Bold.ttf') format('truetype');
	font-weight: 700;
	font-style: normal;
}

@font-face {
	font-family: 'Space Mono';
	src: url('SpaceMono-Regular.ttf') format('truetype');
	font-weight: 400;
	font-style: normal;
}

body {
	font-size: 0.75rem;
	font-family: 'Inter', sans-serif;
	font-weight: 400;
	color: #000000;
	margin: 0 auto;
	position: relative;
}

#pspdfkit-header {
	font-size: 0.625rem;
	text-transform: uppercase;
	letter-spacing: 2px;
	font-weight: 400;
	color: #717885;
	margin-top: 2.5rem;
	margin-bottom: 2.5rem;
	width: 100%;
}

.header-columns {
	display: flex;
	justify-content: space-between;
	padding-left: 2.5rem;
	padding-right: 2.5rem;
}

.logo {
	height: 1.5rem;
	width: auto;
	margin-right: 1rem;
}

.logotype {
	display: flex;
	align-items: center;
	font-weight: 700;
}

h2 {
	font-family: 'Space Mono', monospace;
	font-size: 1.25rem;
	font-weight: 400;
}

h4 {
	font-family: 'Space Mono', monospace;
	font-size: 1rem;
	font-weight: 400;
}

.page {
	margin-left: 5rem;
	margin-right: 5rem;
}

.intro-table {
	display: flex;
	justify-content: space-between;
	margin: 3rem 0 3rem 0;
	border-top: 1px solid #000000;
	border-bottom: 1px solid #000000;
}

.intro-form {
	display: flex;
	flex-direction: column;
	border-right: 1px solid #000000;
	width: 50%;
}

.intro-form:last-child {
	border-right: none;
}

.intro-table-title {
	font-size: 0.625rem;
	margin: 0;
}

.intro-form-item {
	padding: 1.25rem 1.5rem 1.25rem 1.5rem;
}

.intro-form-item:first-child {
	padding-left: 0;
}

.intro-form-item:last-child {
	padding-right: 0;
}

.intro-form-item-border {
	padding: 1.25rem 0 0.75rem 1.5rem;
	border-bottom: 1px solid #000000;
}

.intro-form-item-border:last-child {
	border-bottom: none;
}

.form {
	display: flex;
	flex-direction: column;
	margin-top: 6rem;
}

.no-border {
	border: none;
}

.border {
	border: 1px solid #000000;
}

.border-bottom {
	border: 1px solid #000000;
	border-top: none;
	border-left: none;
	border-right: none;
}

.signer {
	display: flex;
	justify-content: space-between;
	gap: 2.5rem;
	margin: 2rem 0 2rem 0;
}

.signer-item {
	flex-grow: 1;
}

input {
	color: #4537de;
	font-family: 'Space Mono', monospace;
	text-align: center;
	margin-top: 1.5rem;
	height: 4rem;
	width: 100%;
	box-sizing: border-box;
}

input#date,
input#notes {
	text-align: left;
}

input#signature {
	height: 8rem;
}

.intro-text {
	width: 60%;
}

.table-box table,
.summary-box table {
	width: 100%;
	font-size: 0.625rem;
}

.table-box table {
	padding-top: 2rem;
}

.table-box td:first-child,
.summary-box td:first-child {
	width: 50%;
}

.table-box td:last-child,
.summary-box td:last-child {
	text-align: right;
}

.table-box table tr.heading td {
	border-top: 1px solid #000000;
	border-bottom: 1px solid #000000;
	height: 1.5rem;
}

.table-box table tr.item td,
.summary-box table tr.item td {
	border-bottom: 1px solid #d7dce4;
	height: 1.5rem;
}

.summary-box table tr.no-border-item td {
	border-bottom: none;
	height: 1.5rem;
}

.summary-box table tr.total td {
	border-top: 1px solid #000000;
	border-bottom: 1px solid #000000;
	height: 1.5rem;
}

.summary-box table tr.item td:first-child,
.summary-box table tr.total td:first-child {
	border: none;
	height: 1.5rem;
}

#pspdfkit-footer {
	font-size: 0.5rem;
	text-transform: uppercase;
	letter-spacing: 1px;
	font-weight: 500;
	color: #717885;
	margin-top: 2.5rem;
	bottom: 2.5rem;
	position: absolute;
	width: 100%;
}

.footer-columns {
	display: flex;
	justify-content: space-between;
	padding-left: 2.5rem;
	padding-right: 2.5rem;
}

To access the styles from index.html, use the <link> tag. While referring to the stylesheet file, just use the name of the file and don’t create nested paths:

<!DOCTYPE html>
<html lang="en">
	<head>
		<meta
			http-equiv="Content-Type"
			content="text/html; charset=UTF-8"
		/>
		<link rel="stylesheet" href="style.css" />
		<title>Invoice</title>
	</head>
</html>

Interacting with the API

Now, import requests and json to the pspdfkit.py file. Place the pspdfkit.py file in the root directory of your project:

import requests
import json

Preparing the Payload

Create a dictionary to hold the data you want to send to the API. However, later you’ll need to convert the dictionary to a JSON object using the json.dumps function.

The instructions object references files by the name of their parts that are appended in the form data as files:

instructions = {
    'parts': [
        {
            'html': 'index.html',
            'assets': [
                "style.css",
                "Inter-Regular.ttf",
                "Inter-Medium.ttf",
                "Inter-Bold.ttf",
                "SpaceMono-Regular.ttf",
                "logo.svg",
            ],
        }
    ]
}

To access the requests library, use the request method.

Now, make a POST request to the https://api.pspdfkit.com/build endpoint with the instructions object as the payload. Then, save the resulting PDF as result.pdf in the same folder as the Python file.

Don’t forget to replace YOUR_API_KEY with your API key:

response = requests.request(
    'POST',
    'https://api.pspdfkit.com/build',
    headers={
        'Authorization': 'Bearer {YOUR_API_KEY}', # Replace with your API key.
    },
    files={
        'index.html': open('index.html', 'rb'),
        'style.css': open('style.css', 'rb'),
        'Inter-Regular.ttf': open('Inter-Regular.ttf', 'rb'),
        'Inter-Medium.ttf': open('Inter-Medium.ttf', 'rb'),
        'Inter-Bold.ttf': open('Inter-Bold.ttf', 'rb'),
        'SpaceMono-Regular.ttf': open('SpaceMono-Regular.ttf', 'rb'),
        'logo.svg': open('logo.svg', 'rb'),
    },
    data={
        'instructions': json.dumps(instructions)
    },
    stream=True
)

if response.ok:
    with open('result.pdf', 'wb') as fd:
        for chunk in response.iter_content(chunk_size=8096):
            fd.write(chunk)
else:
    print(response.text)
    exit()

Generating the PDF

Now, run the Python application by executing the following command:

python3 pspdfkit.py

# Or for Python 2

python pspdfkit.py

You can see the full code below:

import requests
import json

instructions = {
    'parts': [
        {
            'html': 'index.html',
            'assets': [
                "style.css",
                "Inter-Regular.ttf",
                "Inter-Medium.ttf",
                "Inter-Bold.ttf",
                "SpaceMono-Regular.ttf",
                "logo.svg",
            ],
        }
    ]
}

response = requests.request(
    'POST',
    'https://api.pspdfkit.com/build',
    headers={
        'Authorization': 'Bearer {YOUR_API_KEY}' # Replace with your API key.
    },
    files={
        'index.html': open('index.html', 'rb'),
        'style.css': open('style.css', 'rb'),
        'Inter-Regular.ttf': open('Inter-Regular.ttf', 'rb'),
        'Inter-Medium.ttf': open('Inter-Medium.ttf', 'rb'),
        'Inter-Bold.ttf': open('Inter-Bold.ttf', 'rb'),
        'SpaceMono-Regular.ttf': open('SpaceMono-Regular.ttf', 'rb'),
        'logo.svg': open('logo.svg', 'rb'),
    },
    data={
        'instructions': json.dumps(instructions)
    },
    stream=True
)

if response.ok:
    with open('result.pdf', 'wb') as fd:
        for chunk in response.iter_content(chunk_size=8096):
            fd.write(chunk)
else:
    print(response.text)
    exit()

Conclusion

In this post, you generated a PDF invoice from an HTML template using our Python PDF generation API. We created similar PDF invoice generation blog posts using sample code from other programming languages:

In addition to templates for generating invoices, we created free templates for other commonly used documents, like receipts, certificates, and reports. If you’re interested in generating other types of documents in Python, check out the following posts:

All our templates are available for you to download on our PDF Generator API page. Feel free to customize or add any CSS to the template to fit your use case or help reflect your company’s brand.

Author

Hulya Masharipov Technical Writer

Hulya is a frontend web developer and technical writer at Nutrient who enjoys creating responsive, scalable, and maintainable web experiences. She’s passionate about open source, web accessibility, cybersecurity privacy, and blockchain.

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API Python HTML How To PDF Generation

How to Generate PDF Invoices from HTML in Python

Requirements

Setup

Creating a CSS File

Interacting with the API

Preparing the Payload

Generating the PDF

Conclusion

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