Copy file reference in variable explorer generates PicklingError

Description

What steps will reproduce the problem?

on attempt to copy from “Variable viewer” cell corresponding to closed file reference (“TextIOWrapper object of _io module”)

Traceback

  File "C:\Anaconda\lib\site-packages\spyder\plugins\variableexplorer\widgets\collectionseditor.py", line 1037, in copy
    obj = self.delegate.get_value(idx)
  File "C:\Anaconda\lib\site-packages\spyder\plugins\variableexplorer\widgets\collectionseditor.py", line 1386, in get_value
    return self.parent().get_value(name)
  File "C:\Anaconda\lib\site-packages\spyder\plugins\variableexplorer\widgets\collectionseditor.py", line 1439, in get_value
    value = self.shellwidget.get_value(name)
  File "C:\Anaconda\lib\site-packages\spyder\plugins\ipythonconsole\widgets\namespacebrowser.py", line 99, in get_value
    timeout=CALL_KERNEL_TIMEOUT).get_value(name)
  File "C:\Anaconda\lib\site-packages\spyder_kernels\comms\commbase.py", line 542, in __call__
    call_dict, call_data, self._comm_id)
  File "C:\Anaconda\lib\site-packages\spyder\plugins\ipythonconsole\comms\kernelcomm.py", line 114, in _get_call_return_value
    call_dict, call_data, comm_id)
  File "C:\Anaconda\lib\site-packages\spyder_kernels\comms\commbase.py", line 420, in _get_call_return_value
    return self._sync_error(reply['value'])
  File "C:\Anaconda\lib\site-packages\spyder_kernels\comms\commbase.py", line 480, in _sync_error
    error_wrapper.raise_error()
  File "C:\Anaconda\lib\site-packages\spyder_kernels\comms\commbase.py", line 90, in raise_error
    raise self.etype(self)
Exception in comms call get_value:

  File "C:\Anaconda\lib\site-packages\spyder_kernels\comms\commbase.py", line 343, in _handle_remote_call
    self._set_call_return_value(msg_dict, return_value)

  File "C:\Anaconda\lib\site-packages\spyder_kernels\comms\commbase.py", line 376, in _set_call_return_value
    comm_id=self.calling_comm_id)

  File "C:\Anaconda\lib\site-packages\spyder_kernels\comms\commbase.py", line 245, in _send_message
    data, protocol=self._comms[comm_id]['pickle_protocol'])]

  File "C:\Anaconda\lib\site-packages\cloudpickle\cloudpickle.py", line 1125, in dumps
    cp.dump(obj)

  File "C:\Anaconda\lib\site-packages\cloudpickle\cloudpickle.py", line 482, in dump
    return Pickler.dump(self, obj)

  File "C:\Anaconda\lib\pickle.py", line 409, in dump
    self.save(obj)

  File "C:\Anaconda\lib\pickle.py", line 476, in save
    f(self, obj) # Call unbound method with explicit self

  File "C:\Anaconda\lib\site-packages\cloudpickle\cloudpickle.py", line 1010, in save_file
    raise pickle.PicklingError("Cannot pickle closed files")

_pickle.PicklingError: Cannot pickle closed files

Versions

• Spyder version: 4.0.1
• Python version: 3.6.7
• Qt version: 5.12.5
• PyQt5 version: 5.12.3
• Operating System: Windows 10

Dependencies

atomicwrites >=1.2.0         :  1.3.0 (OK)
chardet >=2.0.0              :  3.0.4 (OK)
cloudpickle >=0.5.0          :  1.2.2 (OK)
diff_match_patch >=20181111  :  20181111 (OK)
intervaltree                 :  None (OK)
IPython >=4.0                :  7.11.1 (OK)
jedi =0.14.1                 :  0.14.1 (OK)
nbconvert >=4.0              :  5.6.1 (OK)
numpydoc >=0.6.0             :  0.9.2 (OK)
pexpect >=4.4.0              :  4.7.0 (OK)
pickleshare >=0.4            :  0.7.5 (OK)
psutil >=0.3                 :  5.6.7 (OK)
pygments >=2.0               :  2.5.2 (OK)
pylint >=0.25                :  2.4.4 (OK)
pyls >=0.31.2;<0.32.0        :  0.31.7 (OK)
zmq >=17                     :  18.1.1 (OK)
qdarkstyle >=2.7             :  2.7 (OK)
qtawesome >=0.5.7            :  0.6.1 (OK)
qtconsole >=4.6.0            :  4.6.0 (OK)
qtpy >=1.5.0                 :  1.9.0 (OK)
rtree >=0.8.3                :  0.9.3 (OK)
sphinx >=0.6.6               :  2.3.1 (OK)
spyder_kernels >=1.8.1;<2.0.0:  1.8.1 (OK)
watchdog                     :  None (OK)
cython >=0.21                :  0.29.14 (OK)
matplotlib >=2.0.0           :  3.1.2 (OK)
numpy >=1.7                  :  1.18.1 (OK)
pandas >=0.13.1              :  0.25.3 (OK)
scipy >=0.17.0               :  1.3.1 (OK)
sympy >=0.7.3                :  1.5.1 (OK)

[ccordoba12]

@dalthviz, please solve this one by adding PicklingError on line 102 of the file that appears below:

https://github.com/spyder-ide/spyder/blob/cb9e8c1ad135ee65f1c62268c0a2ce2aab7e2514/spyder/plugins/ipythonconsole/widgets/namespacebrowser.py#L95-L103

So, UnpicklingError can be generated when Spyder is unable to deserialize the value that comes from the kernel; and PicklingError when the kernel is unable to serialize the value Spyder is asking for.

[skytter]

Good point - or remove copy option from context menu (for this data type)