Auto_Backup.py

"""
A basic Backup script, that can sync all the files in a folder to a different folder
ultimately creating a backup of the main folder.
Uses MultiThreading for additional speed. Takes a Threshold as user input and compresses
the file bigger than threshold using gzip.
"""

import argparse
import gzip
import os
import shutil
import sys
import threading


def parse_input():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "-t", "--target", nargs=1, required=True, help="Target Backup folder"
    )
    parser.add_argument(
        "-s", "--source", nargs="+", required=True, help="Source Files to be added"
    )
    parser.add_argument(
        "-c",
        "--compress",
        nargs=1,
        type=int,
        help="Gzip threshold in bytes, Deafault 1024KB",
        default=[1024000],
    )
    # Default Threshold is 1024KB

    # Help is triggered when there is no Input Provided
    if len(sys.argv) == 1:
        parser.print_help()
        sys.exit()

    return parser.parse_args()


def size_if_newer(source, target):
    """If newer it returns size, otherwise it returns False"""

    src_stat = os.stat(source)
    try:
        target_ts = os.stat(target).st_mtime
    except FileNotFoundError:
        try:
            target_ts = os.stat(target + ".gz").st_mtime
        except FileNotFoundError:
            target_ts = 0

    # The time difference of one second is necessary since subsecond accuracy
    # of os.st_mtime is striped by copy2
    return src_stat.st_size if (src_stat.st_mtime - target_ts > 1) else False


def threaded_sync_file(source, target, compress):
    """Threading for Synchronized Files"""
    size = size_if_newer(source, target)

    if size:
        thread = threading.Thread(
            target=transfer_file, args=(source, target, size > compress)
        )
        thread.start()
        return thread


def sync_file(source, target, compress):
    size = size_if_newer(source, target)

    if size:
        transfer_file(source, target, size > compress)


def transfer_file(source, target, compress):
    """Either copy or compress and copies the file"""

    try:
        if compress:
            with gzip.open(target + ".gz", "wb") as target_fid:
                with open(source, "rb") as source_fid:
                    target_fid.writelines(source_fid)
            print("Compress {}".format(source))
        else:
            shutil.copy2(source, target)
            print("Copy {}".format(source))
    except FileNotFoundError:
        os.makedirs(os.path.dirname(target))
        transfer_file(source, target, compress)


def sync_root(root, arg):
    target = arg.target[0]
    compress = arg.compress[0]
    threads = []

    for path, _, files in os.walk(root):
        for source in files:
            source = path + "/" + source
            threads.append(threaded_sync_file(source, target + source, compress))
    #            sync_file(source, target + source, compress)
    for thread in threads:
        thread.join()


if __name__ == "__main__":
    arg = parse_input()
    print("------------------------- Start copy -------------------------")
    print("______________________________________________________________")
    for root in arg.source:
        sync_root(root, arg)
    print("______________________________________________________________")
    print("------------------------- Done Done! -------------------------")

"""
Example Usage-
> python Auto_Backup.py --target ./Backup_Folder --source ./Source_Folder -c Threshold
"""