下列Python代码的执行结果是？（ ）
mylist=['Failure','is','the','mother','of','success'] for x in mylist[:]: if len(x)<=3: mylist.append(x) print(mylist)
['Failure','is','the','mother','of','success']
['Failure','is','the','mother','of','success','of','is']
['Failure', 'is', 'the', 'mother', 'of', 'success', 'is', 'of']
['Failure', 'is', 'the', 'mother', 'of', 'success', 'is', 'the', 'of']
