How to extract zip file recursively?

Question

I have a zip file which contains three zip files in it like this:

zipfile.zip\  
    dirA.zip\
         a  
    dirB.zip\
         b  
    dirC.zip\
         c

I want to extract all the inner zip files that are inside the zip file in directories with these names (dirA, dirB, dirC).
Basically, I want to end up with the following schema:

output\  
    dirA\
         a  
    dirB\
         b  
    dirC\
         c

I have tried the following:

import os, re
from zipfile import ZipFile

os.makedirs(directory)  # where directory is "\output"
with ZipFile(self.archive_name, "r") as archive:
    for id, files in data.items():
        if files:
            print("Creating", id)
            dirpath = os.path.join(directory, id)

            os.mkdir(dirpath)

            for file in files:
                match = pattern.match(filename)
                new = match.group(2)
                new_filename = os.path.join(dirpath, new)

                content = archive.open(file).read()
            with open(new_filename, "wb") as outfile:
                outfile.write(content)

But it only extracts the zip file and I end up with:

output\  
    dirA\
         dirA.zip 
    dirB\
         dirB.zip 
    dirC\
         dirC.zip

Any suggestions including code-segments will be much appreciated cause I have tried so many different things and read the docs without success.

Answer 1

When extracting the zip file, you would want to write the inner zip files to memory instead of them on disk. To do this, I've used BytesIO.

Check out this code:

import os
import io
import zipfile

def extract(filename):
    z = zipfile.ZipFile(filename)
    for f in z.namelist():
        # get directory name from file
        dirname = os.path.splitext(f)[0]  
        # create new directory
        os.mkdir(dirname)  
        # read inner zip file into bytes buffer 
        content = io.BytesIO(z.read(f))
        zip_file = zipfile.ZipFile(content)
        for i in zip_file.namelist():
            zip_file.extract(i, dirname)

If you run extract("zipfile.zip") with zipfile.zip as:

zipfile.zip/
    dirA.zip/
        a
    dirB.zip/
        b
    dirC.zip/
        c

Output should be:

dirA/
  a
dirB/
  b
dirC/
  c

Answer 2

For a function that extracts a nested zip file (any level of nesting) and cleans up the original zip files:

import zipfile, re, os

def extract_nested_zip(zippedFile, toFolder):
    """ Extract a zip file including any nested zip files
        Delete the zip file(s) after extraction
    """
    with zipfile.ZipFile(zippedFile, 'r') as zfile:
        zfile.extractall(path=toFolder)
    os.remove(zippedFile)
    for root, dirs, files in os.walk(toFolder):
        for filename in files:
            if re.search(r'\.zip$', filename):
                fileSpec = os.path.join(root, filename)
                extract_nested_zip(fileSpec, root)