Extract metadata values from columns in SharePoint site

[EBIMASTER117]

I am having difficulty extracting the values of metadata fields from the SharePoint site for the file I am looking at.
Here is an example of the columns that I have

I am trying to collect the value of the DocumentDate column.

Sample of the code I have used:
target = Sharepoint_Context.web.get_file_by_server_relative_path(file_url).expand(["listItemAllFields"]).get().execute_query() target.get_property()

This essentially returns "None"
I am using version 2.4.3 of the package. Can you please advise if I am going about this incorrectly or is there something I am missing? @vgrem

Update:

Figured out how to extract the relevant piece of information by collecting the list item and accessing the property from there.

[EBIMASTER117]

Figured out the correct implementation. To access the metadata of the of the file, I had to collect the relative file as a list item, which gives access into the metadata columns, from there I knew what column I wanted and was able to appropriately access the information