Python – How to filter a Django query with a list of values

djangodjango-querysetpython

I'm sure this is a trivial operation, but I can't figure out how it's done.

There's got to be something smarter than this:

ids = [1, 3, 6, 7, 9]

for id in ids:
    MyModel.objects.filter(pk=id)

I'm looking to get them all in one query with something like:

MyModel.objects.filter(pk=[1, 3, 6, 7, 9])

How can I filter a Django query with a list of values?

Blog.objects.filter(pk__in=[1, 4, 7])

if not a:
  print("List is empty")

Using the implicit booleanness of the empty list is quite pythonic.

shutil has many methods you can use. One of which is:

from shutil import copyfile
copyfile(src, dst)

# 2nd option
copy(src, dst)  # dst can be a folder; use copy2() to preserve timestamp

Copy the contents of the file named src to a file named dst. Both src and dst need to be the entire filename of the files, including path.
The destination location must be writable; otherwise, an IOError exception will be raised.
If dst already exists, it will be replaced.
Special files such as character or block devices and pipes cannot be copied with this function.
With copy, src and dst are path names given as strs.

Another shutil method to look at is shutil.copy2(). It's similar but preserves more metadata (e.g. time stamps).

If you use os.path operations, use copy rather than copyfile. copyfile will only accept strings.