Personal Data Mountain – coding strategies

#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
"""
copyimages.py
2013/01/07 19:55:57 Daniel Belasco Rogers dan@planbperformance.net
 
User points script at a root directory and script finds all images for
a certain year derived from the Exif data and copies these images into
a destination folder supplied by the user
 
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
 
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>
"""
 
from optparse import OptionParser
from shutil import copy2
import os
import pyexiv2
import sys
 
def parseargs():
    """
    """
    usage = """
%prog   """
    parser = OptionParser(usage, version="%prog 0.1")
    (options, args) = parser.parse_args()
    if len(args) != 3:
        parser.error("""
Please enter a year in the form YYYY, a directory to search for images
under and a directory to save a copy of the images to
e.g. copyimages.py 2007 "/nfs/photos/" "/media/ext3/"
""")
    year = args[0]
    searchpath = args[1]
    destination = args[2]
    return year, searchpath, destination
 
def getexifdate(pathname):
    """
    get creation date from exif
    """
    metadata = pyexiv2.ImageMetadata(pathname)
    try:
        metadata.read()
    except IOError:
        print "%s Unknown image type" % pathname
        return False
    try:
        tag = metadata['Exif.Photo.DateTimeOriginal']
    except KeyError:
        print '%s tag not set' % pathname
        return False
    return tag.value
 
def findimages(year, searchpath):
    """
    ùse os.walk to find images with .jpg extension
    """
    year = int(year)
    imagelist = []
    for (path, dirs, files) in os.walk(searchpath):
        for f in files:
            pathname = os.path.join(path, f)
            if os.path.splitext(pathname)[1].lower() == '.jpg':
                imagedate = getexifdate(pathname)
                if imagedate:
                    try:
                        imageyear = imagedate.year
                    except AttributeError:
                        print '%s invalid date in exif: %s' % (pathname, imagedate)
                        continue
                    if imageyear == year:
                        imagelist.append(pathname)
    return imagelist
 
def copyimages(imagelist, destination):
    """
    iterate through imagelist, copying images to destination directory
    make the dir in a different way by checking if it is present first
    and making it if not, rather than catching it like this.
    """
    for image in imagelist:
        destinationpath = os.path.join(destination, os.path.split(image)[1])
        print "copying %s to %s" % (image, destinationpath)
        # try:
        copy2(image, destinationpath)
        # except IOError:
        #     os.mkdir(destination)
        #     copy2(image, destination)
        # except OSError as e:
        #     print e
        #     sys.exit(2)
    return
 
def main():
    """
    call all functions within script and print stuff to stdout for
    feedback
    """
    year, searchpath, destination = parseargs()
 
    print "Looking in %s for images from %s" % (searchpath, year)
    imagelist = findimages(year, searchpath)
    print "Found %d images" % len(imagelist)
 
    print "Copying images to %s" % destination
    copyimages(imagelist, destination)
    print "Copied %d images. Script ends here." % len(imagelist)
 
if __name__ == '__main__':
    sys.exit(main())