pdf merger script

pdf_mergers.py

"""
merges pdf files provided in given directory
### Install
`pip install pypdf2`
### Merging files 
- provide files using `-f or --files flag`	
>`python3 merger.py --files 1_OriginalAndFirstExt.pdf 2_OriginalAndFirstExt.pdf `

### Merging files from directory
- provide input directory (`-i or --input_dir`) which contains pdf
>`python3 merger.py --input_dir inputs --output apple.pdf`

### You can provide output directory using `-o or --output_file` flag
"""
import os
from PyPDF2 import PdfFileMerger
import logging
import argparse

logger = logging.getLogger()

OUTPUT_DIR = 'merged'
OUTPUT_FILE = f'{OUTPUT_DIR}/merged.pdf'
INPUT_DIR = f'inputs'

def main():
    global logger
    logger.setLevel(logging.DEBUG)
    ch = logging.StreamHandler()
    ch.setLevel(logging.INFO)
    formatter = logging.Formatter(
        "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
    )
    ch.setFormatter(formatter)
    logger.addHandler(ch)
    if not os.path.exists(OUTPUT_DIR):
        os.mkdir(OUTPUT_DIR)

    if os.path.exists(OUTPUT_FILE):
        try:
            os.remove(OUTPUT_FILE)
        except: pass

    parser = argparse.ArgumentParser()
    parser.add_argument(
        "-i", "--input_dir",
        type=str,
        help="Directory whose pdf are to be merged"
    )

    parser.add_argument(
        "-f", "--files",
        nargs='+',
        help="provide list of files with -f flag"
    )
    parser.add_argument(
        "-o", "--output_file",
        type=str,
        help="output file name"
    )

    args = parser.parse_args()
    input_dir = args.input_dir
    input_files = args.files
    output_file = args.output_file
    if input_dir or input_files:
        merger = PdfFileMerger(strict=False)
        if input_files:
            logger.info(f"Merging files: {input_files}")
            for _file in input_files:
                merger.append(_file)
        else:
            if input_dir.endswith('/'):
                input_dir = input_dir.strip('/')
            logger.info(f"Merging files from {input_dir} directory")
            for item in os.listdir(input_dir):
                if item.endswith('pdf'):
                    merger.append(f'{input_dir}/{item}')
        if output_file:
            merger.write(output_file)       
            logger.info(f"Merged into: {output_file}")
        else:
            merger.write(OUTPUT_FILE)       
            logger.info(f"Merged into: {OUTPUT_FILE}")
        merger.close()
    else:
        logger.error(f"ERR: --input  or --files arguments")


if __name__ == '__main__':
    main()