def render_args(arglst, argdct):
    """Render arguments for command-line invocation.

    arglst: A list of Argument objects (specifies order)
    argdct: A mapping of argument names to values (specifies rendered values)
    """
    out = ''
    for arg in arglst:
        if arg.name in argdct:
            rendered = arg.render(argdct[arg.name])
            if rendered:
                out += ' '
                out += rendered
    return out
