如何使用pdb的post_mortem方法？

Question

我正在尝试了解如何使用 pdb.post_mortem() 方法。

对于这个给定的文件

# expdb.py
import pdb
import trace

def hello():
  a = 6 * 9
  b = 7 ** 2
  c = a * b
  d = 4 / 0
  print(c)

tracer = trace.Trace()

命令提示符

'''
# first Try

λ python -i expdb.py
>>> pdb.post_mortem()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Program Files\Anaconda3\lib\pdb.py", line 1590, in post_mortem
    raise ValueError("A valid traceback must be passed if no "
ValueError: A valid traceback must be passed if no exception is being handled
'''

'''
# Second Try

λ python -i expdb.py
>>> pdb.post_mortem(traceback=tracer.run('hello()') )
 --- modulename: trace, funcname: _unsettrace
trace.py(77):         sys.settrace(None)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Program Files\Anaconda3\lib\trace.py", line 500, in run
    self.runctx(cmd, dict, dict)
  File "C:\Program Files\Anaconda3\lib\trace.py", line 508, in runctx
    exec(cmd, globals, locals)
  File "<string>", line 1, in <module>
  File "expdb.py", line 8, in hello
    d = 4 / 0
ZeroDivisionError: division by zero
>>>

Answer 1

post_mortem 方法需要一个 traceback 对象，而不是 Trace 对象。 Traceback 对象可以从 sys.exc_info()[2] inside of an except 块中获取，或者您可以直接调用 pdb.post_mortem() 不带参数（在 except 块中）。

但无论哪种方式，您都必须在调试之前捕获异常。

如何使用pdb的post_mortem方法？

how to use the post_mortem method of pdb?

python

pdb