Merge multiple pdf files into one pdf file.

merge_pdf.py

"""
Merge multiple pdf files into one pdf file.

Args:
    f (list/str): List of filenames to merge
    out (str): Save filename to merge all of the files into.

Requires:

  * pip install PyPDF2

"""
import os
import sys
# print(sys.executable)
import glob
import argparse
from PyPDF2 import PdfFileMerger


def merge(files, out=None):
    if len(files) == 0:
        raise ValueError('At least 1 file is required!')
    elif not all(isinstance(f, str) and f.lower().endswith('.pdf') for f in files):
        raise TypeError('All of the given files must be a string filename with a ".pdf" extension.')
    if out is None:
        f_split = os.path.splitext(files[0])
        out = ''.join((f_split[0], '_merged', f_split[1]))
    
    merger = PdfFileMerger()

    # Check if files in directory or glob pattern
    if len(files) == 1:
        if os.path.isdir(files[0]):
            files = glob.glob(os.path.join(files[0], '*.pdf'))
        elif '*' in files[0]:
            files = glob.glob(files[0])
        
    # merge the files
    for pdf in files:
        merger.append(pdf)

    merger.write(out)
    merger.close()
    return out


if __name__ == "__main__":
    P = argparse.ArgumentParser(description='Merge PDF files')
    P.add_argument('files', nargs='*', type=str, help="PDF file names to merge")
    P.add_argument('--out', '-o', default=None, type=str, help='Output file name. If not given the first filename with _merged will be used.')
    
    ARGS = P.parse_args()
    
    files = ARGS.files
    out = ARGS.out

    if len(files) == 0:
        # Ask for file names
        files = []
        while True:
            f = input('Enter a file path (leave blank to stop): ').strip()
            if f:
                files.append(f)
            else:
                break
        
        if not out:
            out = input('Enter a safe filename (leave blank for auto): ').strip() or None

    out = merge(files, out=out)    
    print('File saved to ', out)