Write in-memory data to an encrypted ZIP or 7Z (without using an on-disk temp file)

I have 2 GB of data in memory (for example data = b'ab' * 1000000000) that I would like to write in a encrypted ZIP or 7Z file.

How to do this without writing data to a temporary on-disk file?

Is it possible with only Python built-in tools (+ optionally 7z)?

I've already looked at this:

ZipFile.writestr writes from a in-memory string/bytes which is good but:
ZipFile.setpassword: only for read, and not write
How to create an encrypted ZIP file? : most answers use a file as input (and cannot work with in-memory data), especially the solutions with pyminizip and those with:
```
subprocess.call(['7z', 'a', '-mem=AES256', '-pP4$$W0rd', '-y', 'myarchive.zip']... 
```
Other solutions require to trust an implementation of cryptography by a third-party tool (see comments), so I would like to avoid them.

Solution

7z.exe has the -si flag, which lets it read data for a file from stdin. This way you could still use 7z's commandline from a subprocess even without an extra file:

from subprocess import Popen, PIPE

# inputs
szip_exe = r"C:\Program Files\7-Zip\7z.exe"  # ... get from registry maybe
memfiles = {"data.dat" : b'ab' * 1000000000}
arch_filename = "myarchive.zip"
arch_password = "Swordfish"

for filename, data in memfiles.items():
    args = [szip_exe, "a", "-mem=AES256", "-y", "-p{}".format(arch_password),
        "-si{}".format(filename), output_filename]
    proc = Popen(args, stdin=PIPE, stdout=PIPE, stderr=PIPE)
    proc.stdin.write(data)
    proc.stdin.close()    # causes 7z to terminate 
    # proc.stdin.flush()  # instead of close() when on Mac, see comments
    proc.communicate()    # wait till it actually has

The write() takes somewhat above 40 seconds on my machine, which is quite a lot. I can't say though if that's due to any inefficiencies from piping the whole data through stdin or if it's just how long compressing and encrypting a 2GB file takes. EDIT: Packing the file from HDD took 47 seconds on my machine, which speaks for the latter.