Custom incremental backup for maya. It creates an OLD directory and copy the working file in this directory and increment it version number.

incremental_backup_maya.py

import os
import re
import glob
from shutil import copyfile
import maya.cmds as cmds

BACKUP_NAME = "OLD"

full_filename_uri = cmds.file(save=True, type='mayaAscii')
filename = os.path.basename(full_filename_uri)
base, extension = os.path.splitext(filename)

working_dir = os.path.dirname(full_filename_uri)
backup_dir = os.path.join(working_dir, BACKUP_NAME)


# Create a BACKUP_NAME directory if it doesn't exist
if not os.path.exists(backup_dir):
    os.makedirs(backup_dir)
    print "Directory %s did not exist, creating..."% (backup_dir)

backuped_files = glob.glob(os.path.join(backup_dir, base) + "_v*" + extension)
if not backuped_files:
    print "No backuped files found"    
    # Create first file if it does not exist
    copyfile(full_filename_uri, os.path.join(
        backup_dir, base + '_v1' + extension))
else:

    print "Found files", backuped_files

    # Sort file by the integer name to find the last file
    sorted_backuped_files = sorted(
        backuped_files, key=lambda x: int(re.findall("(?<=v)\d+", x)[0]))
    last_file = os.path.basename(sorted_backuped_files[-1])
    last_integer = int(last_file.split("_v")[1].split(extension)[0])
    new_file = "%s_v%i%s" % (os.path.join(
        backup_dir, base), last_integer + 1, extension)
    print "Create new file", new_file
    copyfile(full_filename_uri, new_file)