python讓圖片按照exif信息里的創建時間進行排序

我們經常會從不同的設備里取出照片，比如照相機，手機，iphone等等，操作系統記錄的創建日期經常 會因為拷貝等原因變動，下面的代碼可以給圖片按照exif里的創建時間進行排序，非常有用。

import os
import shutil
import Image
from PIL.ExifTags import TAGS

def print_all_known_exif_tags():
    for k in sorted(TAGS):
        print k, TAGS[k]
def print_all_exif_tags(image):
    try:
        img = Image.open(image)
    except Exception, e:
        print image, "skipping due to", e
    else:
        xf = img._getexif()
        for tag in xf:
            print TAGS.get(tag), xf[tag]
    finally:
        print 'done'
def get_minimum_creation_time(exif_data):
    mtime = "?"
    if 306 in exif_data and exif_data[306] < mtime: # 306 = DateTime
        mtime = exif_data[306]
    if 36867 in exif_data and exif_data[36867] < mtime: # 36867 = DateTimeOriginal
        mtime = exif_data[36867]
    if 36868 in exif_data and exif_data[36868] < mtime: # 36868 = DateTimeDigitized
        mtime = exif_data[36868]
    return mtime
def get_creationdate_with_filename_as_dict(list_of_folders):
    print "Processing all image files in:"

result = {}
for folder in list_of_folders:
    print "- " + folder
    counter = 0
    for f in os.listdir(folder):
        counter += 1
        fullFileName = folder + "\\" + f
        try:
            img = Image.open(fullFileName)
        except Exception, e:
            print "    Skipping '%s' due to exception: %s"%(f, e)
            continue
        mtime = get_minimum_creation_time(img._getexif())
        i = 0
        while mtime+"_"*i in result:
            i += 1
        mtime = mtime+"_"*i
        result[mtime] = fullFileName
    print "  Found %s orignal files in %s."%(counter, folder)
print "Added total of %s to dictionary."%len(result)
return result



def copy_from_image_dict_to_directory(image_dict, output_dir):
    assert os.path.exists(output_dir)
    for i,key in enumerate(sorted(image_dict)):
        dummy, extension =  os.path.splitext(image_dict[key])
        new_file_name = key.replace(":", "-") + extension
        output_file = output_dir + new_file_name
        shutil.copy2(image_dict[key], output_file)
    print "Copied %s files to %s"%(i+1, output_dir)
if name=="main":
    source_dir = "/var/tmp/images"
    output_dir = "/var/tmp/output"

# obtain /var/tmp/images/iPhone, /var/tmp/images/CanonPowerShot, /var/tmp/images/Nikon1
list_of_folders = [source_dir + subfolder for subfolder in os.listdir(source_dir)]

all_files = get_creationdate_with_filename_as_dict(list_of_folders)
copy_from_image_dict_to_directory(all_files, output_dir)</pre>