Possible bug: pdb causes exception

[cklb]

BPO	46535
Nosy	@cklb

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2022-01-26.11:20:07.032>
labels = ['type-bug', 'library', '3.10']
title = 'Possible bug: pdb causes exception'
updated_at = <Date 2022-01-27.15:39:46.150>
user = 'https://github.com/cklb'

bugs.python.org fields:

activity = <Date 2022-01-27.15:39:46.150>
actor = 'cklb'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2022-01-26.11:20:07.032>
creator = 'cklb'
dependencies = []
files = []
hgrepos = []
issue_num = 46535
keywords = []
message_count = 1.0
messages = ['411738']
nosy_count = 1.0
nosy_names = ['cklb']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue46535'
versions = ['Python 3.10']

[cklb]

Consider a script called snippet.py, containing the lines

------------------------------------------

import numpy as np
import pandas as pd

np.finfo(float)
idx = pd.MultiIndex.from_tuples([(1, 2)])
np.finfo(float)
print("Done")

---

When running via 'python snippet.py' no errors occur. However when running via 'python -m pdb snippet.py' the following happens:
> snippet.py(1)<module>()
-> import numpy as np
(Pdb) r
--Return--
> snippet.py(6)<module>()->None
-> np.finfo(float)
(Pdb) c
Traceback (most recent call last):
  File "VENV/lib/python3.10/site-packages/numpy/core/getlimits.py", line 459, in __new__
    dtype = numeric.dtype(dtype)
TypeError: 'NoneType' object is not callable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.10/pdb.py", line 1723, in main
    pdb._runscript(mainpyfile)
  File "/usr/lib/python3.10/pdb.py", line 1583, in _runscript
    self.run(statement)
  File "/usr/lib/python3.10/bdb.py", line 597, in run
    exec(cmd, globals, locals)
  File "<string>", line 1, in <module>
  File "snippet.py", line 6, in <module>
    np.finfo(float)
  File "VENV/lib/python3.10/site-packages/numpy/core/getlimits.py", line 462, in __new__
    dtype = numeric.dtype(type(dtype))
TypeError: 'NoneType' object is not callable
Uncaught exception. Entering post mortem debugging
Running 'cont' or 'step' will restart the program

Commenting the MultiIndex line will will get rid of the problem but I am not quite sure why.

Please note that this error only occurs if the script is run via 'r' in pdb. Running via 'c' does not cause any problems.
Therefore, I suspect that the problem may be with pdb instead of the external packages.

My setup:
$ python --version
Python 3.10.1
$ pip list | grep numpy
numpy 1.22.1
$ pip list | grep pandas
pandas 1.4.0

[damarvin]

Hi,
I see this when debugging in PyCharm, and I cannot downgrade to python 3.9.

(besides commenting out the try-except in numpy/core/getlimits.py::finfo.__new__)
Is there a workaround?

[iritkatriel]

@cklb

Are you still seeing this problem? I'm unable to reproduce it with Python 3.10.4. (numpy-1.23.0, pandas-1.4.3).

iritkatriel@Irits-MBP cpython-654 % python3.10 -m pdb xx.py         
> /Users/iritkatriel/src/cpython-654/xx.py(1)<module>()
-> import numpy as np
(Pdb) r
Done
--Return--
> /Users/iritkatriel/src/cpython-654/xx.py(7)<module>()->None
-> print("Done")
(Pdb) c
The program finished and will be restarted
> /Users/iritkatriel/src/cpython-654/xx.py(1)<module>()
-> import numpy as np
(Pdb) list
  1  ->	import numpy as np
  2  	import pandas as pd
  3  	
  4  	np.finfo(float)
  5  	idx = pd.MultiIndex.from_tuples([(1, 2)])
  6  	np.finfo(float)
  7  	print("Done")
  8