def download_file(url, dest=None, chunk_size=1024, replace="ask",
                  label="Downloading {dest_basename} ({size:.2f}MB)",
                  expected_extension=None):
    """Download a file from a given URL and display progress.

    :param dest: If the destination exists and is a directory, the filename
        will be guessed from the Content-Disposition header. If the destination
        is an existing file, the user will either be prompted to overwrite, or
        the file will be replaced (depending on the value of **replace**). If
        the destination does not exist, it will be used as the filename.
    :param int chunk_size: bytes read in at a time.
    :param replace: If `False`, an existing destination file will not be
        overwritten.
    :param label: a string which is formatted and displayed as the progress bar
        label. Variables provided include *dest_basename*, *dest*, and *size*.
    :param expected_extension: if set, the filename will be sanitized to ensure
        it has the given extension. The extension should not start with a dot
        (`.`).
    """
    dest = Path(dest or url.split("/")[-1])
    response = get(url, stream=True)
    if (dest.exists()
            and dest.is_dir()
            and "Content-Disposition" in response.headers):
        content_disposition = rfc6266.parse_requests_response(response)
        if expected_extension is not None:
            filename = content_disposition.filename_sanitized(
                expected_extension)
        filename = secure_filename(filename)
        dest = dest / filename
    if dest.exists() and not dest.is_dir():
        if (replace is False
                or replace == "ask"
                and not click.confirm("Replace {}?".format(dest))):
            return str(dest)
    size = int(response.headers.get("content-length", 0))
    label = label.format(dest=dest, dest_basename=dest.name,
                         size=size/1024.0/1024)
    with click.open_file(str(dest), "wb") as f:
        content_iter = response.iter_content(chunk_size=chunk_size)
        with click.progressbar(content_iter, length=size/1024,
                               label=label) as bar:
            for chunk in bar:
                if chunk:
                    f.write(chunk)
                    f.flush()
    return str(dest)
def modify(self, dn, changes, controls=None):

        self.result = { 'dn' : '',
                        'referrals' : None,
                        'description' : 'success',
                        'result' : 0,
                        'message' : '',
                        'type' : 'modifyResponse'}

        # Check to see if the user exists in the directory
        try:
            index = self._find_user(dn)
        except StopIteration:
            # If we get here the user doesn't exist so continue
            self.result["description"] = "failure"
            self.result["result"] = 32
            self.result["message"] = "Error no such object: {0!s}".format(dn)
            return False

        # extract the hash we are interested in
        entry = self.directory[index].get("attributes")

        # Loop over the changes hash and apply them
        for k, v in changes.items():
            if v[0] == "MODIFY_DELETE":
                entry.pop(k)
            elif v[0] == "MODIFY_REPLACE" or v[0] == "MODIFY_ADD":
                entry[k] = v[1][0]
            else:
                self.result["result"] = 2
                self.result["message"] = "Error bad/missing/not implemented" \
                    "modify operation: %s" % k[1]

        # Place the attributes back into the directory hash
        self.directory[index]["attributes"] = entry

        # Attempt to write changes to disk
        with open(DIRECTORY, 'w+') as f:
            f.write(str(self.directory))

        return True