Prevent AttributeError when deleting a partially initialized Plotter

[adeak]

Breaking a Plotter on __init__() led to two errors:

>>> pv.Plotter(potato='invalid')
Exception ignored in: <function BasePlotter.__del__ at 0x7fe0183279d0>
Traceback (most recent call last):
  File "/home/adeak/pyvista/pyvista/plotting/plotting.py", line 4595, in __del__
    self.deep_clean()
  File "/home/adeak/pyvista/pyvista/plotting/plotting.py", line 3348, in deep_clean
    self.disable_picking()
  File "/home/adeak/pyvista/pyvista/plotting/picking.py", line 1160, in disable_picking
    if self._picker is not None:
AttributeError: 'Plotter' object has no attribute '_picker'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: __init__() got an unexpected keyword argument 'potato'

Guarding against attribute access of self._picker in Plotter.disable_picking() (called during __del__()) fixes this:

>>> pv.Plotter(potato='invalid')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: __init__() got an unexpected keyword argument 'potato'

[codecov]

Codecov Report

Merging #2819 (f0e7053) into main (ffba268) will increase coverage by 0.05%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2819      +/-   ##
==========================================
+ Coverage   93.95%   94.00%   +0.05%     
==========================================
  Files          76       76              
  Lines       16356    16355       -1     
==========================================
+ Hits        15367    15375       +8     
+ Misses        989      980       -9     

[akaszynski]

Thanks! I’ve run into this before and it’s nice to have this cleaned up.

LGTM.