How to generate barcode and sign document using Python Leave feedback

Barcodes represent textual information as a quite small image that could be automatically scanned. Such an approach brings new opportunities in the computer processing of documents like sorting or moving through a business workflow. In this article, we will discuss useful ways to sign electronic documents with data encrypted in Bar or QR codes using Python.

GroupDocs.Signature for Python via .NET provides API for signing a wide range of document formats. Moreover, API includes special abilities for additional document content processing. Supported formats are PDF, Microsoft Word, Microsoft PowerPoint, Microsoft Excel, PNG, JPEG, and many others.

Use pip to install the package:

pip install groupdocs-signature-net

It is a common problem to add additional data to various types of business documents. Such a document may look as in the picture below. One of the most useful ways is to place a barcode directly on the document page.

To generate a barcode and sign a particular document with it:

• Instantiate the Signature class providing a path to the source document or document stream.
• Create the BarcodeSignOptions instance and set up all demanded fields.
• Invoke the sign method to process the document, providing the output file path and sign options.

from groupdocs.signature import Signature
from groupdocs.signature.domain import BarcodeTypes, HorizontalAlignment
from groupdocs.signature.options import BarcodeSignOptions


def sign_pdf_with_codabar():
    # Initialize signature handler
    with Signature("sample.pdf") as signature:
        # Create barcode signature options
        barcode_options = BarcodeSignOptions()
        barcode_options.horizontal_alignment = HorizontalAlignment.RIGHT
        barcode_options.top = 150
        barcode_options.encode_type = BarcodeTypes.CODABAR
        barcode_options.text = "19/06/2022"

        # Sign document
        result = signature.sign("signed_codabar.pdf", barcode_options)
        print(f"Barcodes added: {len(result.succeeded)}")


if __name__ == "__main__":
    sign_pdf_with_codabar()

Binary file (PDF, 46 KB)

Codabar encodes digits and the characters - $ : / . + only. Other characters are dropped without an error: the text Approved_19/06/2022 would be encoded as 19/06/2022. Pick a symbology such as Code 128 when the text contains letters.

A document signed with a Codabar might look like in the picture below. The Codabar format was developed for printed documents and might be useful in office document flow.

The Barcode Generator Online App provides an opportunity to try document signing with barcodes for free.

Another way to improve documents is to generate the barcode first and then add it to documents using third-party tools. For this case, it is possible to generate code as an image.

• Create the BarcodeSignOptions class instance and set up all the demanded fields.
• Instantiate the PreviewSignatureOptions object providing the methods for creation and releasing of the image stream.
• Invoke the static Signature.generate_signature_preview method to obtain the barcode image as a stream.
• Use the resultant barcode stream in any possible way.

import io

from groupdocs.signature import Signature
from groupdocs.signature.domain import BarcodeTypes
from groupdocs.signature.options import BarcodeSignOptions, PreviewSignatureOptions


def generate_barcode_image():
    # Create a memory stream to store the barcode image
    result = io.BytesIO()

    # Setup barcode signature options
    barcode_options = BarcodeSignOptions()
    barcode_options.encode_type = BarcodeTypes.CODE93
    barcode_options.text = "Case 148-01"

    # Create preview options
    preview_options = PreviewSignatureOptions(
        barcode_options,
        lambda options: result,  # Create the image stream
        lambda options, stream: None,  # Release the image stream
    )

    # Generate image to stream; no document is needed
    Signature.generate_signature_preview(preview_options)

    # Use the barcode image, for example save it for a third-party tool
    with open("barcode_result.png", "wb") as image_file:
        image_file.write(result.getvalue())
    print(f"Barcode image: {len(result.getvalue())} bytes")


if __name__ == "__main__":
    generate_barcode_image()

Binary file (PNG, 2 KB)

An image containing the generated barcode might look in this way:

In order to use the API without evaluation limitations, you can get a free temporary license.

To sum up, some useful ways of processing documents and barcodes were discussed in this article. Using Python improves the productivity of such actions dramatically. In addition, you can use the Barcode Generator Online App to generate barcodes and/or sign your files with barcodes for free.

Read the documentation to learn how to use GroupDocs.Signature in your Python applications. Also, you may discuss any questions or issues at the GroupDocs forum.

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