def get(url, session=None, silent=not debug, **kwargs):
    """Retrieve a given URL and log response.

    :param session: a :class:`requests.Session` object.
    :param silent: if **True**, response status and URL will not be printed.
    """
    session = session or requests
    kwargs["verify"] = kwargs.get("verify", True)
    r = session.get(url, **kwargs)
    if not silent:
        status_code = click.style(
            str(r.status_code),
            fg="green" if r.status_code in (200, 304) else "red")
        click.echo(status_code + " " + url)
        if r.status_code == 404:
            raise PackageNotFoundError
    return r
def _parse_filter():
        op = pyparsing.oneOf('! & |')
        lpar  = pyparsing.Literal('(').suppress()
        rpar  = pyparsing.Literal(')').suppress()

        k = pyparsing.Word(pyparsing.alphanums)
        # NOTE: We may need to expand on this list, but as this is not a real
        # LDAP server we should be OK.
        # Value to contain:
        #   numbers, upper/lower case letters, astrisk, at symbol, minus, full
        #   stop, backslash or a space
        v = pyparsing.Word(pyparsing.alphanums + "-*@.\\ äöü")
        rel = pyparsing.oneOf("= ~= >= <=")

        expr = pyparsing.Forward()
        atom = pyparsing.Group(lpar + op + expr + rpar) \
                            | pyparsing.Combine(lpar + k + rel + v + rpar)
        expr << atom + pyparsing.ZeroOrMore( expr )

        return expr