Set the current context to that given.

    Attributes provided by ``context`` override those in the current
    context.  If ``context`` doesn't specify a particular attribute,
    the attribute from the current context shows through.

def setcontext(context, _local=local):
    """
    Set the current context to that given.

    Attributes provided by ``context`` override those in the current
    context.  If ``context`` doesn't specify a particular attribute,
    the attribute from the current context shows through.

    """
    oldcontext = getcontext()
    _local.__bigfloat_context__ = oldcontext + context