on Windows, assuming the file 'foo.zip' exists, the following would cause an
assertion failure in Modules/zipimport.c in zipimport_zipimporter_get_data_impl():

import zipimport

class BadStr(str):
    def replace(self, old, new):
        return 42

zipimport.zipimporter('foo.zip').get_data(BadStr('bar'))


this is because zipimport_zipimporter_get_data_impl() assumes that
BadStr('bar').replace('/', '\\') is a string.