pdf_merger.py

# Import Libraries
from PyPDF4 import PdfFileMerger
import os
import argparse


def merge_pdfs(input_files: list, page_range: tuple, output_file: str, bookmark: bool = True):
    """
    Merge a list of PDF files and save the combined result into the `output_file`.
    `page_range` to select a range of pages (behaving like Python's range() function) from the input files
        e.g (0,2) -> First 2 pages 
        e.g (0,6,2) -> pages 1,3,5
    bookmark -> add bookmarks to the output file to navigate directly to the input file section within the output file.
    """
    # strict = False -> To ignore PdfReadError - Illegal Character error
    merger = PdfFileMerger(strict=False)
    for input_file in input_files:
        bookmark_name = os.path.splitext(os.path.basename(input_file))[0] if bookmark else None
        # pages To control which pages are appended from a particular file.
        merger.append(fileobj=open(input_file, 'rb'), pages=page_range, import_bookmarks=False, bookmark=bookmark_name)
    # Insert the pdf at specific page
    merger.write(fileobj=open(output_file, 'wb'))
    merger.close()


def parse_args():
    """Get user command line parameters"""
    parser = argparse.ArgumentParser(description="Available Options")
    parser.add_argument('-i', '--input_files', dest='input_files', nargs='*',
                        type=str, required=True, help="Enter the path of the files to process")
    parser.add_argument('-p', '--page_range', dest='page_range', nargs='*',
                        help="Enter the pages to consider e.g.: (0,2) -> First 2 pages")
    parser.add_argument('-o', '--output_file', dest='output_file',
                        required=True, type=str, help="Enter a valid output file")
    parser.add_argument('-b', '--bookmark', dest='bookmark', default=True, type=lambda x: (
        str(x).lower() in ['true', '1', 'yes']), help="Bookmark resulting file")
    # To Parse The Command Line Arguments
    args = vars(parser.parse_args())
    # To Display The Command Line Arguments
    print("## Command Arguments #################################################")
    print("\n".join("{}:{}".format(i, j) for i, j in args.items()))
    print("######################################################################")
    return args


if __name__ == "__main__":
    # Parsing command line arguments entered by user
    args = parse_args()
    page_range = None
    if args['page_range']:
        page_range = tuple(int(x) for x in args['page_range'][0].split(','))
    # call the main function
    merge_pdfs(
        input_files=args['input_files'], page_range=page_range, 
        output_file=args['output_file'], bookmark=args['bookmark']
    )