python image resize with ratio

run.py

#!/usr/bin/env python
import PIL
from PIL import Image
import os, sys

mywidth = 1200

path = "/pathtofolder/"
dirs = os.listdir( path )

def resize():
    for item in dirs:
        if os.path.isfile(path+item):
			img = Image.open(path+item)
			wpercent = (mywidth/float(img.size[0]))
			hsize = int((float(img.size[1])*float(wpercent)))
			img = img.resize((mywidth,hsize), PIL.Image.ANTIALIAS)
			img.save(path+'resized/'+item)
resize()