Upload file in chunks not working for zipped files

[davedavemckay]

Large in-memory zip files should be treated like large files and uploaded in chunks, however, this throws FileNotFoundError.

Offending code:

for i in range(chunk_count):
                        start = i * chunk_size
                        end = min(start + chunk_size, file_data_size)
                        part_number = i + 1
                        with open(filename, 'rb') as f:
                            f.seek(start)
                            chunk_data = f.read(end - start)

Cannot open(filename, 'rb') as no file exists on disk.