Merge pdfs by BytesIO

fdf_explore.py

"""Script to generate templates and merge with docs to sign them"""

import io
from fpdf import Template
from PyPDF2 import PdfFileWriter, PdfFileReader


def create_elements(el_dict):
    """Creates a elements dict to customize the template"""
    final_dict = []
    assert isinstance(el_dict, dict)
    max_height = 5 * (len(el_dict)) + 5
    for i in el_dict:
        el = {
            "name": i,
            "type": "T",
            "x1": -40,
            "y1": -(max_height),
            "font": "Arial",
            "size": 6.0,
            "bold": 0,
            "italic": 0,
            "underline": 0,
            "foreground": 0,
            "background": 0,
            "align": "I",
            "text": str(i + " : ") + str(el_dict[i]),
            "priority": 2,
        }
        final_dict.append(el)
        max_height = max_height - 5
    return final_dict


def merge_docs_by_io(inp_io, template_io):
    output = PdfFileWriter()
    input_pdf = PdfFileReader(inp_io)
    template = PdfFileReader(template_io)
    for i in range(input_pdf.getNumPages()):
        input_pdf.getPage(i).mergePage(template.getPage(0))
        output.addPage(input_pdf.getPage(i))
    return output


def create_sign_template(user_content):
    """Generates and returns a bytearry containing the template of the sign doc"""
    elements = create_elements(user_content)
    temp_doc = Template(format="A4", elements=elements)
    temp_doc.add_page()

    temp_doc.render('template_def_out.pdf')

    out_str = temp_doc.render(None, dest='S')
    b_out = io.BytesIO()
    b_out.write(out_str.encode('latin1'))
    b_out.seek(0)

    # Instead of sample.pdf, pass BytesIO. It works
    md = merge_docs_by_io(b_out, 'sample.pdf')
    m_out = io.BytesIO()
    md.write(m_out)
    m_out.seek(0)

    with open('merged.pdf', 'wb') as f:
        f.write(m_out.read())


if __name__ == "__main__":
    create_sign_template(
        {
            "Signed by": "Bharat",
            "Reason": "Loan Document",
            "Signed on": "15/5/2018",
            "Remark": "Signed using mobile and otp",
        }
    )