def format_arg_value(arg_val):
    """Return a string representing a (name, value) pair.

    >>> format_arg_value(('x', (1, 2, 3)))
    'x=(1, 2, 3)'
    """
    arg, val = arg_val
    return "%s=%r" % (arg, val)
Return a string representing a (name, value) pair.

    >>> format_arg_value(('x', (1, 2, 3)))
    'x=(1, 2, 3)'
    
src/watchdog/utils/echo.py