d5300_gps_renew.py

import hashlib
import urllib.request
import os

if not os.path.isdir('NIKON'):
    os.makedirs('NIKON')

if os.path.exists('NIKON/NML_28A.ee'):
    with open('NIKON/NML_28A.ee', 'rb') as f:
        checksum = hashlib.sha1(f.read()).hexdigest()
        print("Old file: %s" % checksum)
else:
    checksum = 'invalid'

with urllib.request.urlopen('http://crossgate.nikonimglib.com/dsd_redirect/redirect.do?P=F9JnZ07&R=SLOnf25&L=uTmf400&O=CVMiG00') as response:
    newfile = response.read()
    newhash = hashlib.sha1(newfile).hexdigest()
    print("New file: %s" % newhash)

    if checksum == newhash:
        print("already up to date")
        exit(0)

    with open('NIKON/NML_28A.ee', 'wb') as f:
        f.write(newfile)
    
    with open('NIKON/NML_28A.ee', 'rb') as f:
        checksum = hashlib.sha1(f.read()).hexdigest()
        print("Updated: %s" % checksum)