Python仅打印最后的追溯？

Question

Consider the following code and traceback:

>>> try:
...  raise KeyboardInterrupt
... except KeyboardInterrupt:
...  raise Exception
... 
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
KeyboardInterrupt

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 4, in <module>
Exception
>>> 

I'd like to print only the most recent traceback (the one in which Exception was raised).
How can this be achieved?

---

From the above example, I'd like to print the following, as if raise Exception had been called outside the except clause.

Traceback (most recent call last):
  File "<stdin>", line 4, in <module>
Exception

Answer 1

The perfect question for me.

You can suppress the exception context, that is the first part of the traceback, by explicitly raising the exception from None :

>>> try:
        raise KeyboardInterrupt
    except:
        raise Exception from None

Traceback (most recent call last):
  File "<pyshell#4>", line 4, in <module>
    raise Exception from None
Exception

This was formalized in PEP 409 and further improved in PEP 415 . The original bug request for this was filed by myself btw.

---

Note that suppressing the context will not actually remove the context from the new exception. So you can still access the original exception:

try:
    try:
        raise Exception('inner')
    except:
        raise Exception('outer') from None
except Exception as e:
    print(e.__context__) # inner