TinyPNG API via Python. Optimizes .png and .jpg files in the current directory and outputs to "optimized/".

tiny.py

from __future__ import print_function

import os
import tinify

tinify.key = ""  # Fill your developer key here
exts = ("jpg", "png", "jpeg")
basewidth = 1500
files = [f for f in os.listdir(".") if os.path.isfile(f) and f.endswith(exts)]

for f in files:
    print("Optimizing %s" % f)
    source = tinify.from_file(f)
    resized = source.resize(method="scale", width=basewidth)
    resized.to_file("optimized/%s" % f)