#NEWLINE# def iter_fields( node ) : #NEWLINE# #INDENT# '\n    Yield a tuple of ``(fieldname, value)`` for each field in ``node._fields``\n    that is present on *node*.\n    ' #NEWLINE# for field in node . _fields : #NEWLINE# #INDENT# try : #NEWLINE# #INDENT# ( yield ( field , getattr ( node , field ) ) ) #NEWLINE# #UNINDENT# except AttributeError : #NEWLINE# #INDENT# pass