Search and replace for text within a pdf, in Python [duplicate]

This can be done with PyPDF2 package. The implementation may depend on the original PDF template structure. But if the template is stable enough and isn’t changed very often the replacement code shouldn’t be generic but rather simple.

I did a small sketch on how you could replace the text inside a PDF file. It replaces all occurrences of PDF tokens to DOC.

import os
import argparse
from PyPDF2 import PdfFileReader, PdfFileWriter
from PyPDF2.generic import DecodedStreamObject, EncodedStreamObject


def replace_text(content, replacements = dict()):
    lines = content.splitlines()

    result = ""
    in_text = False

    for line in lines:
        if line == "BT":
            in_text = True

        elif line == "ET":
            in_text = False

        elif in_text:
            cmd = line[-2:]
            if cmd.lower() == 'tj':
                replaced_line = line
                for k, v in replacements.items():
                    replaced_line = replaced_line.replace(k, v)
                result += replaced_line + "\n"
            else:
                result += line + "\n"
            continue

        result += line + "\n"

    return result


def process_data(object, replacements):
    data = object.getData()
    decoded_data = data.decode('utf-8')

    replaced_data = replace_text(decoded_data, replacements)

    encoded_data = replaced_data.encode('utf-8')
    if object.decodedSelf is not None:
        object.decodedSelf.setData(encoded_data)
    else:
        object.setData(encoded_data)


if __name__ == "__main__":
    ap = argparse.ArgumentParser()
    ap.add_argument("-i", "--input", required=True, help="path to PDF document")
    args = vars(ap.parse_args())

    in_file = args["input"]
    filename_base = in_file.replace(os.path.splitext(in_file)[1], "")

    # Provide replacements list that you need here
    replacements = { 'PDF': 'DOC'}

    pdf = PdfFileReader(in_file)
    writer = PdfFileWriter()

    for page_number in range(0, pdf.getNumPages()):

        page = pdf.getPage(page_number)
        contents = page.getContents()

        if isinstance(contents, DecodedStreamObject) or isinstance(contents, EncodedStreamObject):
            process_data(contents, replacements)
        elif len(contents) > 0:
            for obj in contents:
                if isinstance(obj, DecodedStreamObject) or isinstance(obj, EncodedStreamObject):
                    streamObj = obj.getObject()
                    process_data(streamObj, replacements)

        writer.addPage(page)

    with open(filename_base + ".result.pdf", 'wb') as out_file:
        writer.write(out_file)

The results are

UPDATE 2021-03-21:

Updated the code example to handle DecodedStreamObject and EncodedStreamObject which actually contian data stream with text to update.