Saves the new version of the file with right numeric postfix. For instance, ex.ma will be saved as ex_01.ma. ex_02.ma will be saved as ex_03.ma, etc.

MagicSave.py

'''
_______________________________________
Name: magicSave
Version: 1.1
Author: Alexander Smirnov
e-mail: [email protected]
site: fabis.xyz
_______________________________________

Instructions:
Put the script into the Maya script folder, for example:
C:\Users\ USERNAME \Documents\maya\ MAYAVERSION \scripts

Assign the code to the hotkey press (for instance Ctrl+S - press):
import magicSave; magicSave.run()

and the code to the hotkey release (for instance Ctrl+S - release):
import magicSave; magicSave.save()

If you press the hotkey shortly (less than 0.4 sec.) it will save the scene in a default way, if you hold the key longer (more than 0.4 sec.) it will save it in the next way:
1. If existing scene called 'Scene.ma', it will save it as 'Scene_01.ma'
2. If existing scene called 'Scene_01.ma', it will save it as 'Scene_02.ma', etc.
Note that if you will save the current scene with the name 'Scene_01.ma', but in this directory exists similar files with postfixes, till, for instance 'Scene_05.ma',
it will show you the prompt dialog window, where it will ask you to overwrite the next version 'Scene_02.ma', save the last scene as 'Scene_06.ma' or cancel the operation.

_______________________________________

'''
import maya.cmds as mc
import maya.mel as mel
import re
import os

def run():
	global mSaveTimer
	mSaveTimer = mc.timerX()

def save():
	global mSaveTimer
	checkTime = mc.timerX(st=mSaveTimer)
	if checkTime<0.4:
		mel.eval( 'checkForUnknownNodes(); FileMenu_SaveItem' )
	else:
		sn = mc.file( q=1, exn=1 ).rsplit( '/', 1 )
		m = re.search( r'\d+$', sn[1][:-3] )
		xName = 1
		nName = ''
		finName = None
		if m:
			nName = re.sub( m.group() + '$', '', sn[1][:-3] ) + '%02d' % ( int( m.group() ) + 1 ) + sn[1][-3:]
		else:
			nName = sn[1][:-3] + '_' + '%02d' % ( xName ) + sn[1][-3:]

		if os.path.exists(sn[0] + '/' + nName):
			cName = nName
			while os.path.exists(sn[0] + '/' + cName):
				sn = (sn[0] + '/' + cName).rsplit( '/', 1 )
				m = re.search( r'\d+$', sn[1][:-3] )
				cName = re.sub( m.group() + '$', '', sn[1][:-3] ) + '%02d' % ( int( m.group() ) + 1 ) + sn[1][-3:]

			result = mc.promptDialog( title='Save scene', tx=cName, message='Next version(s) already exists, save the last one?:', button=[ 'Save last', 'Overwrite next', 'Cancel'], defaultButton='Save as last', cancelButton='Cancel', dismissString='Cancel')

			if result == 'Save last':
				finName = mc.promptDialog( query=1, text=1)
			elif result == 'Overwrite':
				finName = nName
		else:
			finName = nName

		if finName:
			mc.file( rename=sn[0] + '/' + finName )
			mc.file( f=1, s=1 )