How to load a DBF file within a zip file to a variable without extracting it in Python?

Question

I am trying to load a DBF file that is contained within a zip file into a variable without extracting the zip file. I have tried using the following code, but it is not working:

import zipfile
from dbfread import DBF

def load_dbf_from_zip(zip_filename):
    with zipfile.ZipFile(zip_filename, 'r') as z:
        dbf_filename = z.namelist()[0]
        with z.open(dbf_filename) as f:
            dbf = DBF(f)
    return dbf

dbf = load_dbf_from_zip('my_zip_file.zip')

This code is not working because it is trying to read the DBF file from the zip file using the DBF constructor, which expects a file object as input. However, the open() method of the ZipFile class returns a ZipExtFile object, which is not a file object.

How can I load the DBF file into a variable without extracting the zip file?

Answer 1

It looks like you can't. The library you are using expects a filename as first argument to DBS(), then tries to open and read the file itself. Moreover, the DBS class seems to open and read the file multiple times in internal functions, so you can't just create a temporary file and delete it after instantiating DBS(filename). Pretty silly unfortunately.

You will have to either extract the file to disk or create a NamedTemporaryFile, write data to it and pass its name to DBS. That file should lives as long as the DBS class you work with though.

Overall, I would say this library offers a pretty poor interface, the underlying file could even change and the library will re-open it after it has changed, which I am not sure is something one would normally expect.