code: def from_path_by_size(dir_path, min_size=0, max_size=1 << 40):
          
          def filter(winfile):
              if (winfile.size_on_disk >= min_size) and \
                  (winfile.size_on_disk <= max_size):
                  return True
              else:
                  return False
  
          return FileCollection.from_path_by_criterion(
              dir_path, filter, keepboth=False)
docs: Create a new FileCollection, and select all files that size in
          a range::
              
              dir_path = "your/path"
              
              # select by file size larger than 100MB
              fc = FileCollection.from_path_by_size(
                  dir_path, min_size=100*1024*1024)
              
              # select by file size smaller than 100MB
              fc = FileCollection.from_path_by_size(
                  dir_path, max_size=100*1024*1024)
                  
              # select by file size from 1MB to 100MB
              fc = FileCollection.from_path_by_size(
                  dir_path, min_size=1024*1024, max_size=100*1024*1024)