Python比较XML.Etree以及目录列表中的文件和文件夹名称的差异

Question

I'm using Python to compare my flickr photos to my local harddrive photo directories.

In order to do this, I'm using OAuth in Python and getting an etree listing of each folder/album I have in flickr. The folder/album contents on flickr 'should' match my local copy directory.

I'd like my script to tell me when there are items not in my photo listing on my local drive and flickr (and vice versa).

The 'title' field of the flickr photos should be the same as the filename on Linux and directory names on Linux will/should match the album names on flickr. That is currently how I have it set up.

I'm wondering what would be the best and most efficient way to compare these item lists in Python (etree node items vs os.listdir() items)?

I'd rather not get into using sort() in bash to sort any piped output to filenames unless necessary. I'd like to keep everything in Python if possible as I'm just learning it.

I could use os.listdir() and compare that to the XML.Etree nodes returned to flickr, but what would be the best approach to do this comparison?

Keep in mind that the lists may not be the same and may not be sorted when comparing items from flickr and Linux.

I have the following snippet of code written to get results from flickr:

...oauth code above...
sets = flickr.photosets.getList(user_id=user_id)
print ("Total sets: " + sets.find('photosets').attrib['total'])
all_sets = sets.find('photosets').findall('photoset')

for each_set in all_sets:
   for node in each_set.findall('title'):
      print ("photoset: " + each_set.get('id') + ", " + node.text + ", photos: ", each_set.get('photos'))
      all_photos = flickr.photosets.getPhotos(user_id=user_id, photoset_id=each_set.get('id'))
      photos = all_photos.find('photoset')
      for photo in photos:
         print (photo.get('title'))

An example of the output from the above code would be:

photoset: 72157659163323894, Birthday Party - Nov 21, 2015, photos:  131
...
2015:11:21-16:11:14-IMG_20151121_161114372
2015:11:21-16:11:10-IMG_20151121_161109739
2015:11:21-16:10:36-IMG_20151121_161035497
2015:11:21-15:47:14-IMG_20151121_154713671
2015:11:21-15:43:17-IMG_20151121_154317180
2015:11:21-15:43:15-IMG_20151121_154315539
2015:11:21-15:23:42-IMG_20151121_152342348
2015:11:21-15:23:11-IMG_20151121_152311411
...
2015:11:21-16:21:19-DSC_0603
2015:11:21-16:21:13-DSC_0602
2015:11:21-16:21:11-DSC_0601
2015:11:21-16:21:09-DSC_0600
2015:11:21-16:21:07-DSC_0599
2015:11:21-16:21:05-DSC_0598
2015:11:21-16:20:13-DSC_0597
2015:11:21-16:20:09-DSC_0596
2015:11:21-16:19:59-DSC_0595
2015:11:21-16:19:56-DSC_0594
2015:11:21-16:19:55-DSC_0593
...

The API for getPhotos is here: https://www.flickr.com/services/api/flickr.photosets.getPhotos.htm which shows some of the example xtree/XML output.

Etree API: https://docs.python.org/2/library/xml.etree.elementtree.html

Answer 1

To check if the file from your flickr exist on your hd:

not_on_hd = []
for file in flickr_photos:
    if os.path.exists("path/to/"+file):
        continue
    else:
        not_on_hd.append(file)
print(not_on_hd)

To do it the other way around I'd use a simple if file_on_drive is in flickr_photos , and append the ones that return false to a list, just like above.

not_on_flickr = []
for file_on_drive in files_on_drive:
    if file_on_drive in flickr_photos:
        continue
    else:
        not_on_flickr.append(file_on_drive)
print(not_on_flickr)

Since you asked for efficiency: pop() any files that have been found in the first run from the list, making the second run shorter.

not_on_hd = []
for i,file in enumerate(flickr_photos):
    if os.path.exists("/path/to/"+file):
        continue
    else:
        not_on_hd.append(file)
        flickr_photos.pop(i)
print(not_on_hd)

Here's some docs on what I did up there:
enumerate() - python3 docs
is in - Python3 Docs (Section 6.10.2) (And the difference between is and == here )

Answer 2

Birds eye view:

1. Create a set (datatype set !) of full path names from the XML.
2. Create another set of full path names from your local file system.
3. Use set operations to get the paths missing on either side.