Is it possible to generate and return a ZIP file with App Engine?

Question

I have a small project that would be perfect for Google App Engine. Implementing it hinges on the ability to generate a ZIP file and return it.

Due to the distributed nature of App Engine, from what I can tell, the ZIP file couldn't be created "in-memory" in the traditional sense. It would basically have to be generated and and sent in a single request/response cycle.

Does the Python zip module even exist in the App Engine environment?

Answer 1

zipfile is available at appengine and reworked example follows:

from contextlib import closing
from zipfile import ZipFile, ZIP_DEFLATED

from google.appengine.ext import webapp
from google.appengine.api import urlfetch

def addResource(zfile, url, fname):
    # get the contents      
    contents = urlfetch.fetch(url).content
    # write the contents to the zip file
    zfile.writestr(fname, contents)

class OutZipfile(webapp.RequestHandler):
    def get(self):
        # Set up headers for browser to correctly recognize ZIP file
        self.response.headers['Content-Type'] ='application/zip'
        self.response.headers['Content-Disposition'] = \
            'attachment; filename="outfile.zip"'    

        # compress files and emit them directly to HTTP response stream
        with closing(ZipFile(self.response.out, "w", ZIP_DEFLATED)) as outfile:
            # repeat this for every URL that should be added to the zipfile
            addResource(outfile, 
                'https://www.google.com/intl/en/policies/privacy/', 
                'privacy.html')
            addResource(outfile, 
                'https://www.google.com/intl/en/policies/terms/', 
                'terms.html')