python 中打印堆栈的详细信息

import traceback

class MyClass(object):

    def __init__(self, name):
        self.name = name

    def sayName(self):
        try:
            print(self.num)
            return self.name
        except Exception:
            # traceback.print_exc(file=open('error.log','a+'))
            traceback.print_exc()
            return 'aaa2'


x = MyClass('adley')
print(x.sayName())

Traceback (most recent call last):
  File "/Users/adleytales/studyspace/python-playground/class.py", line 10, in sayName
    print(self.num)
AttributeError: 'MyClass' object has no attribute 'num'
aaa2