How to get value of arguments passed to functions on the stack?

Question

Using:

traceback.print_stack()

I can get:

  File "x.py", line 20, in <module>
    y(x)
  File "x.py", line 11, in y
    fun(x)
  File "x.py", line 8, in fun
    traceback.print_stack()

I there any way to get something like this:

  File "x.py", line 20, in <module>
    y(x) WHERE x == 1
  File "x.py", line 11, in y
    fun(x) WHERE x == 'str'
  File "x.py", line 8, in fun
    traceback.print_stack()

I just want to see what arguments was passed to functions.

Answer 1

You can probably rig something up by using inspect.getargvalues() and accessing the stack frame belonging to your traceback:

 inspect.getargvalues(traceback.tb_frame)

You'll have to do some work to get the output exactly as desired. The above line is only for the innermost frame, so you'll have to walk up the stack and access the information you need for every frame. inspect.getouterframes() might come in handy.

Answer 2

You can use the inspect module for this:

>>> import inspect
... def fn(x):
...     try:
...         print(1/0)
...     except ZeroDivisionError as e:
...         frames = inspect.trace()
...         argvalues = inspect.getargvalues(frames[0][0])
...         print("Argvalues: ", inspect.formatargvalues(*argvalues))
>>> fn(12)
Argvalues:  (x=12)