ActiveState Code

#!/usr/bin/python

__version__ = '$Id: exif_redater.py 470 2008-03-06 06:40:14Z mn $'

USAGE = "exif_redater.py\n\tredate .jpg/.jpeg files according to EXIF data"

"""
Iterates through a directory, reading the EXIF data from each jpg/jpeg file.
Parses the date/time from EXIF data and if it differs from file
modification date/time then changes file date/time

author: Michal Niklas
"""

import os
import os.path
import sys
import time

import EXIF

ALL_CNT = 0
CHANGED_CNT = 0

# which file should be checked
EXTENSIONS = ('.jpg', '.jpeg')

# what tags use to redate file (use first found)
DT_TAGS = ["Image DateTime", "EXIF DateTimeOriginal", "DateTime"]


def show_fdt(fdt):
	"""human readable format of file modification datetime"""
	return time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime(fdt))


def exif_info2time(ts):
	"""changes EXIF date ('2005:10:20 23:22:28') to number of seconds since 1970-01-01"""
	tpl = time.strptime(ts, '%Y:%m:%d %H:%M:%S')
	return time.mktime(tpl)


def redate_by_exif(fn):
	"""reads EXIF from jpg/jpeg and if file datetime differs from EXIF changes file date"""
	global ALL_CNT, CHANGED_CNT
	ALL_CNT += 1
	dt_value = None
	exif_time = None
	s = os.stat(fn)
	f = open(fn, 'rb')
	try:
		tags = EXIF.process_file(f)
		for dt_tag in DT_TAGS:
			try:
				dt_value = "%s" % tags[dt_tag]
				break
			except:
				continue
		if dt_value:
			file_time = s[8]
			exif_time = exif_info2time(dt_value)
	finally:
		f.close()
	if exif_time:
		secs_diff = file_time - exif_time
		MAX_DIFF = 130.0
		if secs_diff > MAX_DIFF or secs_diff < -MAX_DIFF:
			print "%s    %s -> %s" % (fn, show_fdt(file_time), show_fdt(exif_time))
			os.utime(fn, (exif_time, exif_time))
			CHANGED_CNT += 1


def process_dir(_, dir_name, files):
	"""looks for .jpg/.jpeg file in dir"""
	for fname in files:
		can_change = False
		fnl = fname.lower()
		for ext in EXTENSIONS:
			if fnl.endswith(ext):
				can_change = True
				break
		if can_change:
			fname = os.path.join(dir_name, fname)
			if os.path.isfile(fname):
				try:
					redate_by_exif(fname)
				except:
					pass


def main():
	os.path.walk('.', process_dir, None)
	print '\nChecked: %d\nChanged %d\n' % (ALL_CNT, CHANGED_CNT)


if '--version' in sys.argv:
	print __version__
else:
	if __name__ == '__main__':
		if '--help' in sys.argv:
			print USAGE
		else:
			main()