Comparing file name and file size to determine new files

Question

I am writing a script that will sync a remote SFTP folder with a local folder and only download files that do not exist in the remote folder or have a different file size. paramiko has a st_size method that will return the file size. os has a similar method.

What I can not figure out is how to compare the file name and the file size at the same time. I could create a list of lists, like so:

files = [
  ['file_name1.txt', 123456],
  ['file_name2.txt', 234567]
]

Then loop over these results.

Or I could create a dictionary where the file name is the key and the file size is the value, then iterate over the dict.

files = {'file_name1.txt': 123456, 'file_name2.txt': 234567}

Is there a best practice here to compare two variables at the same time?

Answer 1

Using list would be better option, for the following reasons:

• dictionary uses more resources than list. (Only valid for Python < 3.6, this would matter if there are 100s of element)
• List are indexed so, you can access the items without actually knowing both filename or its size, however dictionary needs at least a key or value, which is not possible with dictionary.

Some beneficial links:

• About memory space
• Dictionary vs List