Error pickling MCNP_Problem: Cannot pickle 'generator' object

[tjlaboss]

Cannot pickle montepy.MCNP_Problem objects.

Describe the bug

Since v0.3.0, can no longer pickle montepy.MCNP_Problem for more complicated input decks. The MCNP_Problem contains an unpicklable generator object. Rolling back to v0.2.10 fixes this.

This occurs when the problem contains tallies (possibly other non-implemented data cards?).

This is not caught by tests/test_interface.py::TestBrinyFermentation .

To Reproduce / Error Message

>>> deck = montepy.read_input("path/to/input.imcnp")
>>> with open("path/to/pickle.pkl", 'wb') as pkl:
...    pickle.dump(deck, pkl)
TypeError: cannot pickle 'generator' object

MCNP input file snippet

MCNP Test Model for Tallies
1 1 20 -1000  imp:n,p=1 U=350 trcl=5
2 2 8  -1005  imp:n=1    imp:p=0.5
3 3 -1  1000 1005 -1010 imp:n,p=1
99 0 1010     imp:n,p=0
5 0   #99     imp:n,p=3 fill=350 (1 0 0 ) 

C surfaces
1000 SO 1
1005 RCC 0 1.5 -0.5 0 0 1 0.25
1010 SO 3

C data
C materials
C UO2 5 atpt enriched
m1        92235.80c           5 &
92238.80c          95
C Iron
m2        26054.80c        5.85
          26056.80c       91.75
          26057.80c        2.12
          26058.80c        0.28 
C water
m3        1001.80c           2
          8016.80c           1
MT3 lwtr.23t h-zr.20t h/zr.28t
C
C Tallies --> This breaks MontePy!
f7:n 1
C
C execution
ksrc 0 0 0 
kcode 100000 1.000 50 1050
phys:p j 1 2j 1
mode n p 
vol NO 2J 1 1.5 J

Versions

• 0.3.0,
• 0.3.1,
• 0.3.2

[MicahGale]

This sounds familiar to an old issue.

[tjlaboss]

Issue #189

Something broke the ability to pickle inputs between then and now (for inputs with some as-yet unidentified complexity that is not tested tallies).

[tjlaboss]

Created #468 to test this.

[MicahGale]

Thanks for doing this. I'm not sure if tests/inputs/test.imcnp is the best place for this though. Every time the file is updated a lot of tests have to be updated because I hard code in what the file is in a lot of places. Probably not the best test design.

[MicahGale]

Long term: https://docs.python.org/3/library/pickle.html#handling-stateful-objects this is probably a solution that is needed along with #193.